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Sample records for chytrid fungus batrachochytrium

  1. Waterfowl: potential environmental reservoirs of the chytrid fungus Batrachochytrium dendrobatidis

    OpenAIRE

    Garmyn, An; Van Rooij, Pascale; Pasmans, Frank; Hellebuyck, Tom; Van den Broeck, Wim; Haesebrouck, Freddy; Martel, An

    2012-01-01

    Infections with Batrachochytrium dendrobatidis (B. dendrobatidis), the causal agent of chytridiomycosis, have been shown to play an important role in the decline of amphibians worldwide. Spread of the fungus is poorly understood. Bird movement might possibly contribute to the spread of B. dendrobatidis in the environment. Therefore, 397 wild geese in Belgium were screened for presence of B. dendrobatidis on their toes using real-time quantitative PCR (qPCR). In addition, chemotaxis towards, a...

  2. The Amphibian Chytrid Fungus, Batrachochytrium dendrobatidis, in Fully Aquatic Salamanders from Southeastern North America

    OpenAIRE

    Chatfield, Matthew W. H.; Moler, Paul; Richards-Zawacki, Corinne L.

    2012-01-01

    Little is known about the impact that the pathogenic amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), has on fully aquatic salamander species of the eastern United States. As a first step in determining the impacts of Bd on these species, we aimed to determine the prevalence of Bd in wild populations of fully aquatic salamanders in the genera Amphiuma, Necturus, Pseudobranchus, and Siren. We sampled a total of 98 salamanders, representing nine species from sites in Florida, Miss...

  3. Presence of the Amphibian Chytrid Fungus Batrachochytrium dendrobatidis in Native Amphibians Exported from Madagascar

    OpenAIRE

    Kolby, Jonathan E.

    2014-01-01

    The emerging infectious disease chytridiomycosis is driven by the spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd), a highly virulent pathogen threatening global amphibian biodiversity. Although pandemic in distribution, previous intensive field surveys have failed to detect Bd in Madagascar, a biodiversity hotspot home to hundreds of endemic amphibian species. Due to the presence of Bd in nearby continental Africa and the ecological crisis that can be expected followin...

  4. Terrestrial Dispersal and Potential Environmental Transmission of the Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis)

    OpenAIRE

    Kolby, Jonathan E.; Sara D Ramirez; Berger, Lee; Richards-Hrdlicka, Kathryn L.; Jocque, Merlijn; Lee F Skerratt

    2015-01-01

    Dispersal and exposure to amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) is not confined to the aquatic habitat, but little is known about pathways that facilitate exposure to wild terrestrial amphibians that do not typically enter bodies of water. We explored the possible spread of Bd from an aquatic reservoir to terrestrial substrates by the emergence of recently metamorphosed infected amphibians and potential deposition of Bd-positive residue on riparian vegetation in Cusuco...

  5. Infection of an invasive frog Eleutherodactylus coqui by the chytrid fungus Batrachochytrium dendrobatidis in Hawaii

    OpenAIRE

    Beard, Karen H.; O'Neill, Eric M.

    2005-01-01

    The chytrid fungus Batrachochytrium dendrobatidis has contributed to declines and extinctions of amphibians worldwide. B. dendrobatidis is known to infect the frog Eleutherodactylus coqui in its native Puerto Rico. E. coqui was accidentally introduced into Hawaii in the late 1980s, where there are now hundreds of populations. B. dendrobatidis was being considered as a biological control agent for E. coqui because there are no native amphibians in Hawaii. Using a DNA-based assay, we tested 382...

  6. Chytrid fungus Batrachochytrium dendrobatidis has nonamphibian hosts and releases chemicals that cause pathology in the absence of infection

    OpenAIRE

    McMahon, Taegan A.; Laura A Brannelly; Chatfield, Matthew W. H.; Johnson, Pieter T. J.; Joseph, Maxwell B.; Valerie J McKenzie; Richards-Zawacki, Corinne L.; Venesky, Matthew D.; Rohr, Jason R.

    2012-01-01

    Batrachochytrium dendrobatidis, a pathogenic chytrid fungus implicated in worldwide amphibian declines, is considered an amphibian specialist. Identification of nonamphibian hosts could help explain the virulence, heterogeneous distribution, variable rates of spread, and persistence of B. dendrobatidis in freshwater ecosystems even after amphibian extirpations. Here, we test whether mosquitofish (Gambusia holbrooki) and crayfish (Procambarus spp. and Orconectes virilis), which are syntopic wi...

  7. West Africa - A Safe Haven for Frogs? A Sub-Continental Assessment of the Chytrid Fungus (Batrachochytrium dendrobatidis)

    OpenAIRE

    Penner, Johannes; Adum, Gilbert B.; McElroy, Matthew T.; Doherty-Bone, Thomas; Hirschfeld, Mareike; Sandberger, Laura; Weldon, Ché; Cunningham, Andrew A; Ohst, Torsten; Wombwell, Emma; Portik, Daniel M.; Reid, Duncan; Hillers, Annika; Ofori-Boateng, Caleb; Oduro, William

    2013-01-01

    A putative driver of global amphibian decline is the panzootic chytrid fungus Batrachochytrium dendrobatidis (Bd). While Bd has been documented across continental Africa, its distribution in West Africa remains ambiguous. We tested 793 West African amphibians (one caecilian and 61 anuran species) for the presence of Bd. The samples originated from seven West African countries - Bénin, Burkina Faso, Côte d'Ivoire, Ghana, Guinea, Liberia, Sierra Leone - and were collected from a variety of habi...

  8. West Africa – a safe haven for frogs? A sub–continental assessment of the Chytrid Fungus (Batrachochytrium dendrobatidis)

    OpenAIRE

    Penner, Johannes; Weldon, Ché; Adum, Gilbert B.; McElroy, Matthew T.; Doherty-Bone, Thomas

    2013-01-01

    A putative driver of global amphibian decline is the panzootic chytrid fungus Batrachochytrium dendrobatidis (Bd). While Bd has been documented across continental Africa, its distribution in West Africa remains ambiguous. We tested 793 West African amphibians (one caecilian and 61 anuran species) for the presence of Bd. The samples originated from seven West African countries - Be´nin, Burkina Faso, Coˆ te d’Ivoire, Ghana, Guinea, Liberia, Sierra Leone - and were collected from a var...

  9. First survey for the amphibian chytrid fungus Batrachochytrium dendrobatidis in Connecticut (USA) finds widespread prevalence.

    Science.gov (United States)

    Richards-Hrdlicka, Kathryn L; Richardson, Jonathan L; Mohabir, Leon

    2013-02-28

    The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) is an emerging infectious fungal pathogen of amphibians and is linked to global population declines. Until now, there has only been 1 survey for the fungus in the northeastern USA, which focused primarily on northern New England. We tested for Bd in a large number of samples (916 individuals from 116 sites) collected throughout the state of Connecticut, representing 18 native amphibian species. In addition, 239 preserved wood frog Lithobates sylvaticus tadpoles from throughout the state were screened for the fungus. Bd presence was assessed in both the fresh field swabs and the preserved samples using a sensitive quantitative PCR assay. Our contemporary survey found widespread Bd prevalence throughout Connecticut, occurring in 14 species and in 28% of all sampled animals. No preserved L. sylvaticus specimens tested positive for the fungus. Two common species, bullfrogs R. catesbeiana and green frogs R. clamitans had particularly high infection rates (0.21-0.39 and 0.33-0.42, respectively), and given their wide distribution throughout the state, we suggest they may serve as sentinels for Bd occurrence in this region. Further analyses found that several other factors increase the likelihood of infection, including life stage, host sex, and host family. Within sites, ponds with ranids, especially green frogs, increased the likelihood of Bd prevalence. By studying Bd in populations not facing mass declines, the results from this study are an important contribution to our understanding of how some amphibian species and populations remain infected yet exhibit no signs of chytridiomycosis even when Bd is widely distributed. PMID:23446966

  10. First evidence of amphibian chytrid fungus (Batrachochytrium dendrobatidis and ranavirus in Hong Kong amphibian trade.

    Directory of Open Access Journals (Sweden)

    Jonathan E Kolby

    Full Text Available The emerging infectious amphibian diseases caused by amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd and ranaviruses are responsible for global amphibian population declines and extinctions. Although likely to have been spread by a variety of activities, transcontinental dispersal appears closely associated with the international trade in live amphibians. The territory of Hong Kong reports frequent, high volume trade in amphibians, and yet the presence of Bd and ranavirus have not previously been detected in either traded or free-ranging amphibians. In 2012, a prospective surveillance project was conducted to investigate the presence of these pathogens in commercial shipments of live amphibians exported from Hong Kong International Airport. Analysis of skin (Bd and cloacal (ranavirus swabs by quantitative PCR detected pathogen presence in 31/265 (11.7% and in 105/185 (56.8% of amphibians, respectively. In addition, the water in which animals were transported tested positive for Bd, demonstrating the risk of pathogen pollution by the disposal of untreated wastewater. It is uncertain whether Bd and ranavirus remain contained within Hong Kong's trade sector, or if native amphibians have already been exposed. Rapid response efforts are now urgently needed to determine current pathogen distribution in Hong Kong, evaluate potential trade-associated exposure to free-ranging amphibians, and identify opportunities to prevent disease establishment.

  11. Terrestrial Dispersal and Potential Environmental Transmission of the Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis).

    Science.gov (United States)

    Kolby, Jonathan E; Ramirez, Sara D; Berger, Lee; Richards-Hrdlicka, Kathryn L; Jocque, Merlijn; Skerratt, Lee F

    2015-01-01

    Dispersal and exposure to amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) is not confined to the aquatic habitat, but little is known about pathways that facilitate exposure to wild terrestrial amphibians that do not typically enter bodies of water. We explored the possible spread of Bd from an aquatic reservoir to terrestrial substrates by the emergence of recently metamorphosed infected amphibians and potential deposition of Bd-positive residue on riparian vegetation in Cusuco National Park, Honduras (CNP). Amphibians and their respective leaf perches were both sampled for Bd presence and the pathogen was detected on 76.1% (35/46) of leaves where a Bd-positive frog had rested. Although the viability of Bd detected on these leaves cannot be discerned from our quantitative PCR results, the cool air temperature, closed canopy, and high humidity of this cloud forest environment in CNP is expected to encourage pathogen persistence. High prevalence of infection (88.5%) detected in the recently metamorphosed amphibians and frequent shedding of Bd-positive residue on foliage demonstrates a pathway of Bd dispersal between aquatic and terrestrial habitats. This pathway provides the opportunity for environmental transmission of Bd among and between amphibian species without direct physical contact or exposure to an aquatic habitat. PMID:25927835

  12. Genomic Correlates of Virulence Attenuation in the Deadly Amphibian Chytrid Fungus, Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Refsnider, Jeanine M; Poorten, Thomas J; Langhammer, Penny F; Burrowes, Patricia A; Rosenblum, Erica Bree

    2015-11-01

    Emerging infectious diseasespose a significant threat to global health, but predicting disease outcomes for particular species can be complicated when pathogen virulence varies across space, time, or hosts. The pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd) has caused worldwide declines in frog populations. Not only do Bd isolates from wild populations vary in virulence, but virulence shifts can occur over short timescales when Bd is maintained in the laboratory. We leveraged changes in Bd virulence over multiple generations of passage to better understand mechanisms of pathogen virulence. We conducted whole-genome resequencing of two samples of the same Bd isolate, differing only in passage history, to identify genomic processes associated with virulence attenuation. The isolate with shorter passage history (and greater virulence) had greater chromosome copy numbers than the isolate maintained in culture for longer, suggesting that virulence attenuation may be associated with loss of chromosome copies. Our results suggest that genomic processes proposed as mechanisms for rapid evolution in Bd are correlated with virulence attenuation in laboratory culture within a single lineage of Bd. Moreover, these genomic processes can occur over extremely short timescales. On a practical level, our results underscore the importance of immediately cryo-archiving new Bd isolates and using fresh isolates, rather than samples cultured in the laboratory for long periods, for laboratory infection experiments. Finally, when attempting to predict disease outcomes for this ecologically important pathogen, it is critical to consider existing variation in virulence among isolates and the potential for shifts in virulence over short timescales. PMID:26333840

  13. The amphibian chytrid fungus, Batrachochytrium dendrobatidis, in fully aquatic salamanders from Southeastern North America.

    Directory of Open Access Journals (Sweden)

    Matthew W H Chatfield

    Full Text Available Little is known about the impact that the pathogenic amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd, has on fully aquatic salamander species of the eastern United States. As a first step in determining the impacts of Bd on these species, we aimed to determine the prevalence of Bd in wild populations of fully aquatic salamanders in the genera Amphiuma, Necturus, Pseudobranchus, and Siren. We sampled a total of 98 salamanders, representing nine species from sites in Florida, Mississippi, and Louisiana. Overall, infection prevalence was found to be 0.34, with significant differences among genera but no clear geographic pattern. We also found evidence for seasonal variation, but additional sampling throughout the year is needed to clarify this pattern. The high rate of infection discovered in this study is consistent with studies of other amphibians from the southeastern United States. Coupled with previously published data on life histories and population densities, the results presented here suggest that fully aquatic salamanders may be serving as important vectors of Bd and the interaction between these species and Bd warrants additional research.

  14. Prevalence of the amphibian chytrid fungus (Batrachochytrium dendrobatidis) at Buenos Aires National Wildlife Refuge, Arizona, USA

    Science.gov (United States)

    Sigafus, Brent H.; Hossack, Blake R.; Muths, Erin L.; Schwalbe, Cecil R.

    2014-01-01

    Information on disease presence can be of use to natural resource managers, especially in areas supporting threatened and endangered species that occur coincidentally with species that are suspected vectors for disease. Ad hoc reports may be of limited utility (Muths et al. 2009), but a general sense of pathogen presence (or absence) can inform management directed at T&E species, especially in regions where disease is suspected to have caused population declines (Bradley et al. 2002). The Chiricahua Leopard Frog (Lithobates chiricahuensis), a species susceptible to infection by the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) (Bradley et al. 2002), and the non-native, invasive American Bullfrog (L. catesbeianus), a suspected vector for chytridiomycosis (Schloegel et al. 2012, Gervasi et al. 2013), both occur at Buenos Aires National Wildlife Refuge (BANWR) and surrounding lands in southern Arizona. Efforts to eradicate the bullfrog from BANWR began in 1997 (Suhre, 2010). Eradication from the southern portion of BANWR was successful by 2008 but the bullfrog remains present at the Arivaca Cienega and in areas immediately adjacent to the refuge (Fig. 1). Curtailing the re-invasion of the bullfrog into BANWR will require vigilance as to ensure the health of Chiricahua Leopard Frog populations.

  15. Terrestrial Dispersal and Potential Environmental Transmission of the Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis.

    Directory of Open Access Journals (Sweden)

    Jonathan E Kolby

    Full Text Available Dispersal and exposure to amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd is not confined to the aquatic habitat, but little is known about pathways that facilitate exposure to wild terrestrial amphibians that do not typically enter bodies of water. We explored the possible spread of Bd from an aquatic reservoir to terrestrial substrates by the emergence of recently metamorphosed infected amphibians and potential deposition of Bd-positive residue on riparian vegetation in Cusuco National Park, Honduras (CNP. Amphibians and their respective leaf perches were both sampled for Bd presence and the pathogen was detected on 76.1% (35/46 of leaves where a Bd-positive frog had rested. Although the viability of Bd detected on these leaves cannot be discerned from our quantitative PCR results, the cool air temperature, closed canopy, and high humidity of this cloud forest environment in CNP is expected to encourage pathogen persistence. High prevalence of infection (88.5% detected in the recently metamorphosed amphibians and frequent shedding of Bd-positive residue on foliage demonstrates a pathway of Bd dispersal between aquatic and terrestrial habitats. This pathway provides the opportunity for environmental transmission of Bd among and between amphibian species without direct physical contact or exposure to an aquatic habitat.

  16. Presence of amphibian chytrid fungus (Batrachochytrium dendrobatidis) in rainwater suggests aerial dispersal is possible

    Science.gov (United States)

    Kolby, Jonathan E.; Sara D. Ramirez; Lee Berger; Griffin, Dale W.; Merlijn Jocque; Lee F. Skerratt

    2015-01-01

    Abstract Global spread of the pathogenic amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) may involve dispersal mechanisms not previously explored. Weather systems accompanied by strong wind and rainfall have been known to assist the dispersal of microbes pathogenic to plants and animals, and we considered a similar phenomenon might occur with Bd. We investigated this concept by sampling rainwater from 20 precipitation events for the presence of Bd in Cusuco National Park, Honduras: a site where high Bd prevalence was previously detected in stream-associated amphibians. Quantitative PCR analysis confirmed the presence of Bd in rainwater in one (5 %) of the weather events sampled, although viability cannot be ascertained from molecular presence alone. The source of the Bd and distance that the contaminated rainwater traveled could not be determined; however, this collection site was located approximately 600 m from the nearest observed perennial river by straight-line aerial distance. Although our results suggest atmospheric Bd dispersal is uncommon and unpredictable, even occasional short-distance aerial transport could considerably expand the taxonomic diversity of amphibians vulnerable to exposure and at risk of decline, including terrestrial and arboreal species that are not associated with permanent water bodies.

  17. Presence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in native amphibians exported from Madagascar.

    Directory of Open Access Journals (Sweden)

    Jonathan E Kolby

    Full Text Available The emerging infectious disease chytridiomycosis is driven by the spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd, a highly virulent pathogen threatening global amphibian biodiversity. Although pandemic in distribution, previous intensive field surveys have failed to detect Bd in Madagascar, a biodiversity hotspot home to hundreds of endemic amphibian species. Due to the presence of Bd in nearby continental Africa and the ecological crisis that can be expected following establishment in Madagascar, enhanced surveillance is imperative. I sampled 565 amphibians commercially exported from Madagascar for the presence of Bd upon importation to the USA, both to assist early detection efforts and demonstrate the conservation potential of wildlife trade disease surveillance. Bd was detected in three animals via quantitative PCR: a single Heterixalus alboguttatus, Heterixalus betsileo, and Scaphiophryne spinosa. This is the first time Bd has been confirmed in amphibians from Madagascar and presents an urgent call to action. Our early identification of pathogen presence prior to widespread infection provides the necessary tools and encouragement to catalyze a swift, targeted response to isolate and eradicate Bd from Madagascar. If implemented before establishment occurs, an otherwise likely catastrophic decline in amphibian biodiversity may be prevented.

  18. Amphibian chytrid fungus (Batrachochytrium dendrobatidis) in coastal and montane California, USA Anurans

    Science.gov (United States)

    Fellers, Gary M.; Cole, Rebecca A.; Reinitz, David M.; Kleeman, Patrick M.

    2011-01-01

    We found amphibian chytrid fungus (Bd = Batrachochytrium dendrobatidis) to be widespread within a coastalwatershed at Point Reyes National Seashore, California and within two high elevation watersheds at Yosemite NationalPark, California. Bd was associated with all six species that we sampled (Bufo boreas, B. canorus, Pseudacris regilla, Ranadraytonii, R. sierrae, and Lithobates catesbeianus). For those species sampled at 10 or more sites within a watershed, thepercentage of Bd-positive sites varied from a low of 20.7% for P. regilla at one Yosemite watershed to a high of 79.6% forP. regilla at the Olema watershed at Point Reyes. At Olema, the percent of Bd-positive water bodies declined each year ofour study (2005-2007). Because P. regilla was the only species found in all watersheds, we used that species to evaluatehabitat variables related to the sites where P. regilla was Bd-positive. At Olema, significant variables were year, length ofshoreline (perimeter), percentage cover of rooted vegetation, and water depth. At the two Yosemite watersheds, waterdepth, water temperature, and silt/mud were the most important covariates, though the importance of these three factorsdiffered between the two watersheds. The presence of Bd in species that are not declining suggests that some of theamphibians in our study were innately resistant to Bd, or had developed resistance after Bd became established.

  19. Pathogenic Chytrid Fungus Batrachochytrium dendrobatidis, but Not B. salamandrivorans, Detected on Eastern Hellbenders

    OpenAIRE

    Bales, Emma K.; Oliver J Hyman; Loudon, Andrew H.; Harris, Reid N.; Lipps, Gregory; Chapman, Eric; Roblee, Kenneth; John D Kleopfer; Terrell, Kimberly A.

    2015-01-01

    Recent worldwide declines and extinctions of amphibian populations have been attributed to chytridiomycosis, a disease caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd). Until recently, Bd was thought to be the only Batrachochytrium species that infects amphibians; however a newly described species, Batrachochytrium salamandrivorans (Bs), is linked to die-offs in European fire salamanders (Salamandra salamandra). Little is known about the distribution, host range, or origin ...

  20. Salamander chytrid fungus (Batrachochytrium salamandrivorans) in the United States—Developing research, monitoring, and management strategies

    Science.gov (United States)

    Grant, Evan H. Campbell; Muths, Erin L.; Katz, Rachel A; Canessa, Stefano; Adams, Michael J.; Ballard, Jennifer R.; Berger, Lee; Briggs, Cheryl J.; Coleman, Jeremy; Gray, Matthew J.; Harris, M. Camille; Harris, Reid N.; Hossack, Blake R.; Huyvaert, Kathryn P.; Kolby, Jonathan E.; Lips, Karen R.; Lovich, Robert E.; McCallum, Hamish I.; Mendelson, Joseph R., III; Nanjappa, Priya; Olson, Deanna H.; Powers, Jenny G.; Richgels, Katherine L.D.; Russell, Robin E.; Schmidt, Benedikt R.; Spitzen-van der Sluijs, Annemarieka; Watry, Mary Kay; Woodhams, Douglas C.; White, C. LeAnn

    2016-01-01

    The recently (2013) identified pathogenic chytrid fungus, Batrachochytrium salamandrivorans (Bsal), poses a severe threat to the distribution and abundance of salamanders within the United States and Europe. Development of a response strategy for the potential, and likely, invasion of Bsal into the United States is crucial to protect global salamander biodiversity. A formal working group, led by Amphibian Research and Monitoring Initiative (ARMI) scientists from the U.S. Geological Survey (USGS) Patuxent Wildlife Research Center, Fort Collins Science Center, and Forest and Rangeland Ecosystem Science Center, was held at the USGS Powell Center for Analysis and Synthesis in Fort Collins, Colorado, United States from June 23 to June 25, 2015, to identify crucial Bsal research and monitoring needs that could inform conservation and management strategies for salamanders in the United States. Key findings of the workshop included the following: (1) the introduction of Bsal into the United States is highly probable, if not inevitable, thus requiring development of immediate short-term and long-term intervention strategies to prevent Bsal establishment and biodiversity decline; (2) management actions targeted towards pathogen containment may be ineffective in reducing the long-term spread of Bsal throughout the United States; and (3) early detection of Bsal through surveillance at key amphibian import locations, among high-risk wild populations, and through analysis of archived samples is necessary for developing management responses. Top research priorities during the preinvasion stage included the following: (1) deployment of qualified diagnostic methods for Bsal and establishment of standardized laboratory practices, (2) assessment of susceptibility for amphibian hosts (including anurans), and (3) development and evaluation of short- and long-term pathogen intervention and management strategies. Several outcomes were achieved during the workshop, including development

  1. Widespread occurrence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in the southeastern USA

    Science.gov (United States)

    Rothermel, Betsie B.; Walls, Susan C.; Mitchell, Joseph C.; Dodd, C. Kenneth, Jr.; Irwin, Lisa K.; Green, David E.; Vazquez, Victoria M.; Petranka, James W.; Stevenson, Dirk J.

    2008-01-01

     From 1999 to 2006, we sampled >1200 amphibians for the fungal pathogen Batrachochytrium dendrobatidis(Bd) at 30 sites in the southeastern USA. Using histological techniques or PCR assays, we detected chytrid infection in 10 species of aquatic-breeding amphibians in 6 states. The prevalence of chytrid infection was 17.8% for samples of postmetamorphic amphibians examined using skin swab-PCR assays (n = 202 samples from 12 species at 4 sites). In this subset of samples, anurans had a much higher prevalence of infection than caudates (39.2% vs. 5.5%, respectively). Mean prevalence in ranid frogs was 40.7%. The only infected salamanders were Notophthalmus viridescens at 3 sites. We found infected amphibians from late winter through late spring and in 1 autumn sample. Although we encountered moribund or dead amphibians at 9 sites, most mortality events were not attributed to Bd. Chytridiomycosis was established as the probable cause of illness or death in fewer than 10 individuals. Our observations suggest a pattern of widespread and subclinical infections. However, because most of the sites in our study were visited only once, we cannot dismiss the possibility that chytridiomycosis is adversely affecting some populations. Furthermore, although there is no evidence of chytrid-associated declines in our region, the presence of this pathogen is cause for concern given global climate change and other stressors. Although presence-absence surveys may still be needed for some taxa, such as bufonids, we recommend that future researchers focus on potential population-level effects at sites where Bd is now known to occur.

  2. Pathogenic chytrid fungus Batrachochytrium dendrobatidis, but not B. salamandrivorans, detected on eastern hellbenders.

    Science.gov (United States)

    Bales, Emma K; Hyman, Oliver J; Loudon, Andrew H; Harris, Reid N; Lipps, Gregory; Chapman, Eric; Roblee, Kenneth; Kleopfer, John D; Terrell, Kimberly A

    2015-01-01

    Recent worldwide declines and extinctions of amphibian populations have been attributed to chytridiomycosis, a disease caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd). Until recently, Bd was thought to be the only Batrachochytrium species that infects amphibians; however a newly described species, Batrachochytrium salamandrivorans (Bs), is linked to die-offs in European fire salamanders (Salamandra salamandra). Little is known about the distribution, host range, or origin of Bs. In this study, we surveyed populations of an aquatic salamander that is declining in the United States, the eastern hellbender (Cryptobranchus alleganiensis alleganiensis), for the presence of Bs and Bd. Skin swabs were collected from a total of 91 individuals in New York, Pennsylvania, Ohio, and Virginia, and tested for both pathogens using duplex qPCR. Bs was not detected in any samples, suggesting it was not present in these hellbender populations (0% prevalence, 95% confidence intervals of 0.0-0.04). Bd was found on 22 hellbenders (24% prevalence, 95% confidence intervals of 0.16 ≤ 0.24 ≤ 0.34), representing all four states. All positive samples had low loads of Bd zoospores (12.7 ± 4.9 S.E.M. genome equivalents) compared to other Bd susceptible species. More research is needed to determine the impact of Batrachochytrium infection on hellbender fitness and population viability. In particular, understanding how hellbenders limit Bd infection intensity in an aquatic environment may yield important insights for amphibian conservation. This study is among the first to evaluate the distribution of Bs in the United States, and is consistent with another, which failed to detect Bs in the U.S. Knowledge about the distribution, host-range, and origin of Bs may help control the spread of this pathogen, especially to regions of high salamander diversity, such as the eastern United States. PMID:25695636

  3. Pathogenic chytrid fungus Batrachochytrium dendrobatidis, but not B. salamandrivorans, detected on eastern hellbenders.

    Directory of Open Access Journals (Sweden)

    Emma K Bales

    Full Text Available Recent worldwide declines and extinctions of amphibian populations have been attributed to chytridiomycosis, a disease caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd. Until recently, Bd was thought to be the only Batrachochytrium species that infects amphibians; however a newly described species, Batrachochytrium salamandrivorans (Bs, is linked to die-offs in European fire salamanders (Salamandra salamandra. Little is known about the distribution, host range, or origin of Bs. In this study, we surveyed populations of an aquatic salamander that is declining in the United States, the eastern hellbender (Cryptobranchus alleganiensis alleganiensis, for the presence of Bs and Bd. Skin swabs were collected from a total of 91 individuals in New York, Pennsylvania, Ohio, and Virginia, and tested for both pathogens using duplex qPCR. Bs was not detected in any samples, suggesting it was not present in these hellbender populations (0% prevalence, 95% confidence intervals of 0.0-0.04. Bd was found on 22 hellbenders (24% prevalence, 95% confidence intervals of 0.16 ≤ 0.24 ≤ 0.34, representing all four states. All positive samples had low loads of Bd zoospores (12.7 ± 4.9 S.E.M. genome equivalents compared to other Bd susceptible species. More research is needed to determine the impact of Batrachochytrium infection on hellbender fitness and population viability. In particular, understanding how hellbenders limit Bd infection intensity in an aquatic environment may yield important insights for amphibian conservation. This study is among the first to evaluate the distribution of Bs in the United States, and is consistent with another, which failed to detect Bs in the U.S. Knowledge about the distribution, host-range, and origin of Bs may help control the spread of this pathogen, especially to regions of high salamander diversity, such as the eastern United States.

  4. Cell Density Effects of Frog Skin Bacteria on Their Capacity to Inhibit Growth of the Chytrid Fungus, Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Yasumiba, Kiyomi; Bell, Sara; Alford, Ross

    2016-01-01

    Bacterial symbionts on frog skin can reduce the growth of the chytrid fungus Batrachochytrium dendrobatidis (Bd) through production of inhibitory metabolites. Bacteria can be effective at increasing the resistance of amphibians to chytridiomycosis when added to amphibian skin, and isolates can be screened for production of metabolites that inhibit Bd growth in vitro. However, some bacteria use density-dependent mechanism such as quorum sensing to regulate metabolite production. It is therefore important to consider cell density effects when evaluating bacteria as possible candidates for bioaugmentation. The aim of our study was to evaluate how the density of cutaneous bacteria affects their inhibition of Bd growth in vitro. We sampled cutaneous bacteria isolated from three frog species in the tropical rainforests of northern Queensland, Australia, and selected ten isolates that were inhibitory to Bd in standardised pilot trials. We grew each isolate in liquid culture at a range of initial dilutions, sub-sampled each dilution at a series of times during the first 48 h of growth and measured spectrophotometric absorbance values, cell counts and Bd-inhibitory activity of cell-free supernatants at each time point. The challenge assay results clearly demonstrated that the inhibitory effects of most isolates were density dependent, with relatively low variation among isolates in the minimum cell density needed to inhibit Bd growth. We suggest the use of minimum cell densities and fast-growing candidate isolates to maximise bioaugmentation efforts. PMID:26563320

  5. Chytrid fungus Batrachochytrium dendrobatidis has nonamphibian hosts and releases chemicals that cause pathology in the absence of infection.

    Science.gov (United States)

    McMahon, Taegan A; Brannelly, Laura A; Chatfield, Matthew W H; Johnson, Pieter T J; Joseph, Maxwell B; McKenzie, Valerie J; Richards-Zawacki, Corinne L; Venesky, Matthew D; Rohr, Jason R

    2013-01-01

    Batrachochytrium dendrobatidis, a pathogenic chytrid fungus implicated in worldwide amphibian declines, is considered an amphibian specialist. Identification of nonamphibian hosts could help explain the virulence, heterogeneous distribution, variable rates of spread, and persistence of B. dendrobatidis in freshwater ecosystems even after amphibian extirpations. Here, we test whether mosquitofish (Gambusia holbrooki) and crayfish (Procambarus spp. and Orconectes virilis), which are syntopic with many amphibian species, are possible hosts for B. dendrobatidis. Field surveys in Louisiana and Colorado revealed that zoosporangia occur within crayfish gastrointestinal tracts, that B. dendrobatidis prevalence in crayfish was up to 29%, and that crayfish presence in Colorado wetlands was a positive predictor of B. dendrobatidis infections in cooccurring amphibians. In experiments, crayfish, but not mosquitofish, became infected with B. dendrobatidis, maintained the infection for at least 12 wk, and transmitted B. dendrobatidis to amphibians. Exposure to water that previously held B. dendrobatidis also caused significant crayfish mortality and gill recession. These results indicate that there are nonamphibian hosts for B. dendrobatidis and suggest that B. dendrobatidis releases a chemical that can cause host pathology, even in the absence of infection. Managing these biological reservoirs for B. dendrobatidis and identifying this chemical might provide new hope for imperiled amphibians. PMID:23248288

  6. West Africa - a safe haven for frogs? A sub-continental assessment of the chytrid fungus (Batrachochytrium dendrobatidis.

    Directory of Open Access Journals (Sweden)

    Johannes Penner

    Full Text Available A putative driver of global amphibian decline is the panzootic chytrid fungus Batrachochytrium dendrobatidis (Bd. While Bd has been documented across continental Africa, its distribution in West Africa remains ambiguous. We tested 793 West African amphibians (one caecilian and 61 anuran species for the presence of Bd. The samples originated from seven West African countries - Bénin, Burkina Faso, Côte d'Ivoire, Ghana, Guinea, Liberia, Sierra Leone - and were collected from a variety of habitats, ranging from lowland rainforests to montane forests, montane grasslands to humid and dry lowland savannahs. The species investigated comprised various life-history strategies, but we focused particularly on aquatic and riparian species. We used diagnostic PCR to screen 656 specimen swabs and histology to analyse 137 specimen toe tips. All samples tested negative for Bd, including a widespread habitat generalist Hoplobatrachus occipitalis which is intensively traded on the West African food market and thus could be a potential dispersal agent for Bd. Continental fine-grained (30 arc seconds environmental niche models suggest that Bd should have a broad distribution across West Africa that includes most of the regions and habitats that we surveyed. The surprising apparent absence of Bd in West Africa indicates that the Dahomey Gap may have acted as a natural barrier. Herein we highlight the importance of this Bd-free region of the African continent - especially for the long-term conservation of several threatened species depending on fast flowing forest streams (Conraua alleni ("Vulnerable" and Petropedetes natator ("Near Threatened" as well as the "Critically Endangered" viviparous toad endemic to the montane grasslands of Mount Nimba (Nimbaphrynoides occidentalis.

  7. Spatial Assessment of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) in South Africa Confirms Endemic and Widespread Infection

    OpenAIRE

    Tarrant, Jeanne; Cilliers, Dirk; du Preez, Louis H.; Weldon, Ché

    2013-01-01

    Chytridiomycosis has been identified as a major cause of global amphibian declines. Despite widespread evidence of Batrachochytrium dendrobatidis infection in South African frogs, sampling for this disease has not focused on threatened species, or whether this pathogen poses a disease risk to these species. This study assessed the occurrence of Bd-infection in South African Red List species. In addition, all known records of infection from South Africa were used to model the ecological niche ...

  8. Activities of Temporin Family Peptides against the Chytrid Fungus (Batrachochytrium dendrobatidis) Associated with Global Amphibian Declines

    OpenAIRE

    Rollins-Smith, Louise A.; Carey, Cynthia; Conlon, J. Michael; Reinert, Laura K.; Doersam, Jennifer K.; Bergman, Tomas; Silberring, Jerzy; Lankinen, Hilkka; Wade, David

    2003-01-01

    Temporin A and structurally related peptides produced in amphibian dermal granular glands and in wasp venom were tested for growth inhibition of Batrachochytrium dendrobatidis, a pathogen associated with global amphibian declines. Two natural amphibian temporins, a wasp temporin, and six synthetic analogs effectively inhibited growth. Differences in potency due to amino acid substitution suggest that ability to penetrate membranes and form an α-helical structure is important for their effecti...

  9. Spatial assessment of amphibian chytrid fungus (Batrachochytrium dendrobatidis in South Africa confirms endemic and widespread infection.

    Directory of Open Access Journals (Sweden)

    Jeanne Tarrant

    Full Text Available Chytridiomycosis has been identified as a major cause of global amphibian declines. Despite widespread evidence of Batrachochytrium dendrobatidis infection in South African frogs, sampling for this disease has not focused on threatened species, or whether this pathogen poses a disease risk to these species. This study assessed the occurrence of Bd-infection in South African Red List species. In addition, all known records of infection from South Africa were used to model the ecological niche of Bd to provide a better understanding of spatial patterns and associated disease risk. Presence and prevalence of Bd was determined through quantitative real-time PCR of 360 skin swab samples from 17 threatened species from 38 sites across the country. Average prevalence was 14.8% for threatened species, with pathogen load varying considerably between species. MaxEnt was used to model the predicted distribution of Bd based on 683 positive records for South Africa. The resultant probability threshold map indicated that Bd is largely restricted to the wet eastern and coastal regions of South Africa. A lack of observed adverse impacts on wild threatened populations supports the endemic pathogen hypothesis for southern Africa. However, all threatened species occur within the limits of the predicted distribution for Bd, exposing them to potential Bd-associated risk factors. Predicting pathogen distribution patterns and potential impact is increasingly important for prioritising research and guiding management decisions.

  10. Widespread occurrence of the chytrid fungus batrachochytrium dendrobatidis on oregon spotted frogs (rana pretiosa)

    Science.gov (United States)

    Pearl, C.A.; Bowerman, J.; Adams, M.J.; Chelgren, N.D.

    2009-01-01

    The pathogen Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines in multiple continents, including western North America. We investigated Bd prevalence in Oregon spotted frog (Rana pretiosa), a species that has declined across its range in the Pacific Northwest. Polymerase chain reaction analysis of skin swabs indicated that Bd was prevalent within populations (420 of 617 juvenile and adults) and widespread among populations (36 of 36 sites) where we sampled R. pretiosa in Oregon and Washington. We rarely detected Bd in R. pretiosa larvae (2 of 72). Prevalence of Bd in postmetamorphic R. pretiosa was inversely related to frog size. We found support for an interactive effect of elevation and sampling date on Bd: prevalence of Bd generally increased with date, but this effect was more pronounced at lower elevations. We also found evidence that the body condition of juvenile R. pretiosa with Bd decreased after their first winter. Our data indicate that some Oregon spotted frog populations are currently persisting with relatively high Bd prevalence, but the risk posed by Bd is unknown. ?? 2010 International Association for Ecology and Health.

  11. Salamanders increase their feeding activity when infected with the pathogenic chytrid fungus Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Hess, Alexandra; McAllister, Caroline; DeMarchi, Joseph; Zidek, Makenzie; Murone, Julie; Venesky, Matthew D

    2015-10-27

    Immune function is a costly line of defense against parasitism. When infected with a parasite, hosts frequently lose mass due to these costs. However, some infected hosts (e.g. highly resistant individuals) can clear infections with seemingly little fitness losses, but few studies have tested how resistant hosts mitigate these costly immune defenses. We explored this topic using eastern red-backed salamanders Plethodon cinereus and the fungal pathogen Batrachochytrium dendrobatidis (Bd). Bd is generally lethal for amphibians, and stereotypical symptoms of infection include loss in mass and deficits in feeding. However, individuals of P. cinereus can clear their Bd infections with seemingly few fitness costs. We conducted an experiment in which we repeatedly observed the feeding activity of Bd-infected and non-infected salamanders. We found that Bd-infected salamanders generally increased their feeding activity compared to non-infected salamanders. The fact that we did not observe any differences in mass change between the treatments suggests that increased feeding might help Bd-infected salamanders minimize the costs of an effective immune response. PMID:26503775

  12. Physiological responses of Brazilian amphibians to an enzootic infection of the chytrid fungus Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Bovo, Rafael P; Andrade, Denis V; Toledo, Luís Felipe; Longo, Ana V; Rodriguez, David; Haddad, Célio F B; Zamudio, Kelly R; Becker, C Guilherme

    2016-01-13

    Pathophysiological effects of clinical chytridiomycosis in amphibians include disorders of cutaneous osmoregulation and disruption of the ability to rehydrate, which can lead to decreased host fitness or mortality. Less attention has been given to physiological responses of hosts where enzootic infections of Batrachochytrium dendrobatidis (Bd) do not cause apparent population declines in the wild. Here, we experimentally tested whether an enzootic strain of Bd causes significant mortality and alters host water balance (evaporative water loss, EWL; skin resistance, R(s); and water uptake, WU) in individuals of 3 Brazilian amphibian species (Dendropsophus minutus, n = 19; Ischnocnema parva, n = 17; Brachycephalus pitanga, n = 15). Infections with enzootic Bd caused no significant mortality, but we found an increase in R(s) in 1 host species concomitant with a reduction in EWL. These results suggest that enzootic Bd infections can indeed cause sub-lethal effects that could lead to reduction of host fitness in Brazilian frogs and that these effects vary among species. Thus, our findings underscore the need for further assessment of physiological responses to Bd infections in different host species, even in cases of sub-clinical chytridiomycosis and long-term enzootic infections in natural populations. PMID:26758658

  13. A non-lethal technique for detecting the chytrid fungus Batrachochytrium dendrobatidis on tadpoles.

    Science.gov (United States)

    Retallick, Richard W R; Miera, Verma; Richards, Kathryn L; Field, Kimberleigh J; Collins, James P

    2006-09-14

    Batrachochytrium dendrobatidis (Bd) infection on post-metamorphic frogs and salamanders is commonly diagnosed using polymerase chain reaction (PCR) of skin scrapings taken with mildly abrasive swabs. The technique is sensitive, non-lethal, and repeatable for live animals. Tadpoles are generally not sampled by swabbing but are usually killed and their mouthparts excised to test for the pathogen. We evaluated a technique for non-lethal Bd diagnosis using quantitative PCR (qPCR) on swabs scraped over the mouthparts of live tadpoles. The sensitivity of non-lethal (swabbing) and lethal (removal of mouthparts) sampling was assessed using 150 Bd-infected Rana subaquavocalis tadpoles. Swabbing was consistently less sensitive than lethal sampling, but still detected Bd. Experimental Bd prevalence was 41.1% when estimated by destructively sampling mouthparts and 4.7 to 36.6% (mean = 21.4%) when estimated with swabs. Detection rates from swabbing varied with investigator and time since infection. The likelihood of detecting Bd-infected tadpoles was similar regardless of size and developmental stage. Swabbing mouthparts of live tadpoles is a feasible and effective survey technique for Bd, but, because it is less sensitive, more tadpoles must be sampled to estimate prevalence at a confidence level comparable to destructive sampling. PMID:17067076

  14. Mapping the global emergence of Batrachochytrium dendrobatidis, the amphibian chytrid fungus.

    Directory of Open Access Journals (Sweden)

    Deanna H Olson

    Full Text Available The rapid worldwide emergence of the amphibian pathogen Batrachochytrium dendrobatidis (Bd is having a profound negative impact on biodiversity. However, global research efforts are fragmented and an overarching synthesis of global infection data is lacking. Here, we provide results from a community tool for the compilation of worldwide Bd presence and report on the analyses of data collated over a four-year period. Using this online database, we analysed: 1 spatial and taxonomic patterns of infection, including amphibian families that appear over- and under-infected; 2 relationships between Bd occurrence and declining amphibian species, including associations among Bd occurrence, species richness, and enigmatic population declines; and 3 patterns of environmental correlates with Bd, including climate metrics for all species combined and three families (Hylidae, Bufonidae, Ranidae separately, at both a global scale and regional (U.S.A. scale. These associations provide new insights for downscaled hypothesis testing. The pathogen has been detected in 52 of 82 countries in which sampling was reported, and it has been detected in 516 of 1240 (42% amphibian species. We show that detected Bd infections are related to amphibian biodiversity and locations experiencing rapid enigmatic declines, supporting the hypothesis that greater complexity of amphibian communities increases the likelihood of emergence of infection and transmission of Bd. Using a global model including all sampled species, the odds of Bd detection decreased with increasing temperature range at a site. Further consideration of temperature range, rather than maximum or minimum temperatures, may provide new insights into Bd-host ecology. Whereas caution is necessary when interpreting such a broad global dataset, the use of our pathogen database is helping to inform studies of the epidemiology of Bd, as well as enabling regional, national, and international prioritization of conservation

  15. Prevalence of the pathogenic chytrid fungus, Batrachochytrium dendrobatidis, in an endangered population of northern leopard frogs, Rana pipiens

    OpenAIRE

    Govindarajulu Purnima; Houston Barb; Adama Doug; Voordouw Maarten J; Robinson John

    2010-01-01

    Abstract Background Emerging infectious diseases threaten naïve host populations with extinction. Chytridiomycosis, an emerging infectious disease of amphibians, is caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd) and has been linked to global declines in amphibians. Results We monitored the prevalence of Bd for four years in the Northern leopard frog, Rana pipiens, which is critically imperiled in British Columbia (BC), Canada. The prevalence of Bd initially increased and ...

  16. Prevalence of the pathogenic chytrid fungus, Batrachochytrium dendrobatidis, in an endangered population of northern leopard frogs, Rana pipiens

    Directory of Open Access Journals (Sweden)

    Govindarajulu Purnima

    2010-03-01

    Full Text Available Abstract Background Emerging infectious diseases threaten naïve host populations with extinction. Chytridiomycosis, an emerging infectious disease of amphibians, is caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd and has been linked to global declines in amphibians. Results We monitored the prevalence of Bd for four years in the Northern leopard frog, Rana pipiens, which is critically imperiled in British Columbia (BC, Canada. The prevalence of Bd initially increased and then remained constant over the last three years of the study. Young of the year emerging from breeding ponds in summer were rarely infected with Bd. Some individuals cleared their Bd infections and the return rate between infected and uninfected individuals was not significantly different. Conclusions The BC population of R. pipiens appears to have evolved a level of resistance that allows it to co-exist with Bd. However, this small population of R. pipiens remains vulnerable to extinction.

  17. Development of antimicrobial peptide defenses of southern leopard frogs, Rana sphenocephala, against the pathogenic chytrid fungus, Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Holden, Whitney M; Reinert, Laura K; Hanlon, Shane M; Parris, Matthew J; Rollins-Smith, Louise A

    2015-01-01

    Amphibian species face the growing threat of extinction due to the emerging fungal pathogen Batrachochytrium dendrobatidis, which causes the disease chytridiomycosis. Antimicrobial peptides (AMPs) produced in granular glands of the skin are an important defense against this pathogen. Little is known about the ontogeny of AMP production or the impact of AMPs on potentially beneficial symbiotic skin bacteria. We show here that Rana (Lithobates) sphenocephala produces a mixture of four AMPs with activity against B. dendrobatidis, and we report the minimum inhibitory concentration (MIC) of synthesized replicates of these four AMPs tested against B. dendrobatidis. Using mass spectrometry and protein quantification assays, we observed that R. sphenocephala does not secrete a mature suite of AMPs until approximately 12 weeks post-metamorphosis, and geographically disparate populations produce a different suite of peptides. Use of norepinephrine to induce maximal secretion significantly reduced levels of culturable skin bacteria. PMID:25218643

  18. The invasive chytrid fungus of amphibians paralyzes lymphocyte responses

    OpenAIRE

    Fites, J. Scott; Ramsey, Jeremy P.; Holden, Whitney M.; Collier, Sarah P.; Sutherland, Danica M.; Reinert, Laura K.; Gayek, A. Sophia; Dermody, Terence S.; Aune, Thomas M.; Oswald-Richter, Kyra; Rollins-Smith, Louise A.

    2013-01-01

    The chytrid fungus, Batrachochytrium dendrobatidis, causes chytridiomycosis and is a major contributor to global amphibian declines. Although amphibians have robust immune defenses, clearance of this pathogen is impaired. Because inhibition of host immunity is a common survival strategy of pathogenic fungi, we hypothesized that B. dendrobatidis evades clearance by inhibiting immune functions. We found that B. dendrobatidis cells and supernantants impaired lymphocyte proliferation and induced ...

  19. Prevalence of the pathogenic chytrid fungus, Batrachochytrium dendrobatidis, in an endangered population of northern leopard frogs, Rana pipiens

    OpenAIRE

    Voordouw, Maarten J.; Adama, Doug; Houston, Barb; Govindarajulu, Purnima; Robinson, John

    2011-01-01

    Background Emerging infectious diseases threaten naïve host populations with extinction. Chytridiomycosis, an emerging infectious disease of amphibians, is caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd) and has been linked to global declines in amphibians. Results We monitored the prevalence of Bd for four years in the Northern leopard frog, Rana pipiens, which is critically imperiled in British Columbia (BC), Canada. The prevalence of Bd initially increased and then r...

  20. Why Does Amphibian Chytrid (Batrachochytrium dendrobatidis) Not Occur Everywhere? An Exploratory Study in Missouri Ponds

    OpenAIRE

    Strauss, Alex; Smith, Kevin G.

    2013-01-01

    The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), is a globally emerging pathogen that has caused widespread amphibian population declines, extirpations, and extinctions. However, Bd does not occur in all apparently suitable amphibian populations, even within regions where it is widespread, and it is often unclear why Bd occurs in some habitats but not others. In this study, we rigorously surveyed the amphibian and invertebrate biodiversity of 29 ponds in Missouri, screened r...

  1. Elevated temperature clears chytrid fungus infections from tadpoles of the midwife toad, Alytes obstetricans

    OpenAIRE

    Geiger, C C; Küpfer, E; Schär, S; Wolf, S.; Schmidt, B R

    2011-01-01

    The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) is sensitive to high temperature. Hence, exposing amphibians to high temperature may be a method to clear Bd infection. However, the effect of exposure to elevated temperature has never been tested in larval stages or temperate species.We experimentally exposed tadpoles of the toad Alytes obstetricans to low, medium and high temperatures and found that most, but not all, tadpoles lost the infection when exposed to temperature...

  2. Amphibian Chytrid Fungus in Madagascar neither Shows Widespread Presence nor Signs of Certain Establishment

    OpenAIRE

    Kolby, Jonathan E.; Lee F Skerratt

    2015-01-01

    The global spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) is associated with amphibian mass mortality, population decline, and extinction. Over the past decade, concern has been expressed for the potential introduction of Bd to Madagascar, a global hotspot of amphibian biodiversity. Following years without detection, widespread Bd presence in Madagascar has now been reported (Bletz et al. 2015a), raising international conservation concern. Before reacting to this find...

  3. Absence of invasive Chytrid fungus (Batrachochytrium dendrobatidis in native Fijian ground frog (Platymantis vitiana populations on Viwa-Tailevu, Fiji Islands

    Directory of Open Access Journals (Sweden)

    Edward Narayan

    2011-12-01

    Full Text Available We report on the first survey of chytridiomycosis (Batrachochytrium dendrobatidis- Bd in the endangered Fijian ground frog (Platymantis vitiana population on Viwa-Tailevu, Fiji Islands. This fungal pathogen has been implicated as the primary cause of amphibian declines worldwide. Few cases have been reported from tropical Asia however it was recently documented in 4 species of frogs in Indonesia. Two hundred individual frogs were swabbed from 5 different sites on Viwa Island. Swabs were tested to quantify the number of Bd zoospore equivalents using real-time Polymerase Chain Reaction (qPCR technique. We found zero (% prevalence of Bd in ground frogs. The lack of Bd may be due to 1 hot weather all year round inhibiting the spread of Bd, 2 Bd may be absent from Viwa Island due to a lack of amphibian introductions (not introduced or importation of exotic frogs such as Rana catesbeia-na, or Xenopus spp or pet trade spp or 3 the lack of introduction by human vectors due to the geographic isolation, and low visitation of non-local people into the island. While it is difficult to test these hypotheses, a precautionary approach would suggest an effective quarantine is required to protect Fiji’s endemic frogs from future disease outbreak. Conservation effort and research is needed at international level to assist the Fiji government in monitoring and protecting their unique endemic amphibians from outbreaks of B. dendrobatidis.

  4. Inhibition of Local Immune Responses by the Frog-Killing Fungus Batrachochytrium dendrobatidis

    OpenAIRE

    Fites, J. Scott; Reinert, Laura K.; Chappell, Timothy M.; Rollins-Smith, Louise A.

    2014-01-01

    Amphibians are suffering unprecedented global declines. A leading cause is the infectious disease chytridiomycosis caused by the chytrid fungus Batrachochytrium dendrobatidis. Chytridiomycosis is a skin disease which disrupts transport of essential ions leading to death. Soluble factors produced by B. dendrobatidis impair amphibian and mammalian lymphocytes in vitro, but previous studies have not shown the effects of these inhibitory factors in vivo. To demonstrate in vivo inhibition of immun...

  5. Chytrid fungus infections in laboratory and introduced Xenopus laevis populations:assessing the risks for U.K. native amphibians

    OpenAIRE

    Tinsley, Richard C.; Coxhead, Peter George; Stott, Lucy C; Tinsley, Matthew C.; Piccinni, Maya Z.; Guille, Matthew J.

    2015-01-01

    The chytrid fungus Batrachochytrium dendrobatidis (Bd) is notorious amongst current conservation biology challenges, responsible for mass mortality and extinction of amphibian species. World trade in amphibians is implicated in global dissemination. Exports of South African Xenopus laevis have led to establishment of this invasive species on four continents. Bd naturally infects this host in Africa and now occurs in several introduced populations. However, no previous studies have investigate...

  6. Immune Defenses against Batrachochytrium dendrobatidis, a Fungus Linked to Global Amphibian Declines, in the South African Clawed Frog, Xenopus laevis▿

    OpenAIRE

    Ramsey, Jeremy P.; Reinert, Laura K.; Harper, Laura K.; Douglas C Woodhams; Rollins-Smith, Louise A.

    2010-01-01

    Batrachochytrium dendrobatidis is a chytrid fungus that causes the lethal skin disease chytridiomycosis in amphibians. It is regarded as an emerging infectious disease affecting diverse amphibian populations in many parts of the world. Because there are few model amphibian species for immunological studies, little is known about immune defenses against B. dendrobatidis. We show here that the South African clawed frog, Xenopus laevis, is a suitable model for investigating immunity to this path...

  7. Substrate-Specific Gene Expression in Batrachochytrium dendrobatidis, the Chytrid Pathogen of Amphibians

    OpenAIRE

    Rosenblum, Erica Bree; Poorten, Thomas J; Joneson, Suzanne; Settles, Matthew

    2012-01-01

    Determining the mechanisms of host-pathogen interaction is critical for understanding and mitigating infectious disease. Mechanisms of fungal pathogenicity are of particular interest given the recent outbreaks of fungal diseases in wildlife populations. Our study focuses on Batrachochytrium dendrobatidis (Bd), the chytrid pathogen responsible for amphibian declines around the world. Previous studies have hypothesized a role for several specific families of secreted proteases as pathogenicity ...

  8. Why does Amphibian Chytrid (Batrachochytrium dendrobatidis not occur everywhere? An exploratory study in Missouri ponds.

    Directory of Open Access Journals (Sweden)

    Alex Strauss

    Full Text Available The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd, is a globally emerging pathogen that has caused widespread amphibian population declines, extirpations, and extinctions. However, Bd does not occur in all apparently suitable amphibian populations, even within regions where it is widespread, and it is often unclear why Bd occurs in some habitats but not others. In this study, we rigorously surveyed the amphibian and invertebrate biodiversity of 29 ponds in Missouri, screened resident amphibian larvae (Rana (Lithobates sp. for Bd infection, and characterized the aquatic physiochemical environment of each pond (temperature pH, conductivity, nitrogen, phosphorus, and chlorophyll-a. Our goal was to generate hypotheses toward answering the question, "Why does Bd not occur in all apparently suitable habitats?" Bd occurred in assayed amphibians in 11 of the 29 ponds in our study area (38% of ponds. We found no significant relationship between any single biotic or abiotic variable and presence of Bd. However, multivariate analyses (nonmetric multidimensional scaling and permutational tests of dispersion revealed that ponds in which Bd occurred were a restricted subset of all ponds in terms of amphibian community structure, macroinvertebrate community structure, and pond physiochemistry. In other words, Bd ponds from 6 different conservation areas were more similar to each other than would be expected based on chance. The results of a structural equation model suggest that patterns in the occurrence of Bd among ponds are primarily attributable to variation in macroinvertebrate community structure. When combined with recent results showing that Bd can infect invertebrates as well as amphibians, we suggest that additional research should focus on the role played by non-amphibian biota in determining the presence, prevalence, and pathogenicity of Bd in amphibian populations.

  9. Absence of invasive Chytrid fungus (Batrachochytrium dendrobatidis) in native Fijian ground frog (Platymantis vitiana) populations on Viwa-Tailevu, Fiji Islands

    OpenAIRE

    Edward Narayan; Frank Molinia; Jean-Marc Hero

    2011-01-01

    We report on the first survey of chytridiomycosis (Batrachochytrium dendrobatidis- Bd) in the endangered Fijian ground frog (Platymantis vitiana) population on Viwa-Tailevu, Fiji Islands. This fungal pathogen has been implicated as the primary cause of amphibian declines worldwide. Few cases have been reported from tropical Asia however it was recently documented in 4 species of frogs in Indonesia. Two hundred individual frogs were swabbed from 5 different sites on Viwa Island. Swabs were tes...

  10. Endemic infection of the amphibian chytrid fungus in a frog community post-decline.

    Directory of Open Access Journals (Sweden)

    Richard W R Retallick

    2004-11-01

    Full Text Available The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of numerous frog species worldwide. In Queensland, Australia, it has been proposed as the cause of the decline or apparent extinction of at least 14 high-elevation rainforest frog species. One of these, Taudactylus eungellensis, disappeared from rainforest streams in Eungella National Park in 1985-1986, but a few remnant populations were subsequently discovered. Here, we report the analysis of B. dendrobatidis infections in toe tips of T. eungellensis and sympatric species collected in a mark-recapture study between 1994 and 1998. This longitudinal study of the fungus in individually marked frogs sheds new light on the effect of this threatening infectious process in field, as distinct from laboratory, conditions. We found a seasonal peak of infection in the cooler months, with no evidence of interannual variation. The overall prevalence of infection was 18% in T. eungellensis and 28% in Litoria wilcoxii/jungguy, a sympatric frog that appeared not to decline in 1985-1986. No infection was found in any of the other sympatric species. Most importantly, we found no consistent evidence of lower survival in T. eungellensis that were infected at the time of first capture, compared with uninfected individuals. These results refute the hypothesis that remnant populations of T. eungellensis recovered after a B. dendrobatidis epidemic because the pathogen had disappeared. They show that populations of T. eungellensis now persist with stable, endemic infections of B. dendrobatidis.

  11. Effects of pond salinization on survival rate of amphibian hosts infected with the chytrid fungus.

    Science.gov (United States)

    Stockwell, Michelle Pirrie; Storrie, Lachlan James; Pollard, Carla Jean; Clulow, John; Mahony, Michael Joseph

    2015-04-01

    The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of amphibian populations worldwide, but management options are limited. Recent studies show that sodium chloride (NaCl) has fungicidal properties that reduce the mortality rates of infected hosts in captivity. We investigated whether similar results can be obtained by adding salt to water bodies in the field. We increased the salinity of 8 water bodies to 2 or 4 ppt and left an additional 4 water bodies with close to 0 ppt and monitored salinity for 18 months. Captively bred tadpoles of green and golden bell frog (Litoria aurea) were released into each water body and their development, levels of B. dendrobatidis infection, and survival were monitored at 1, 4, and 12 months. The effect of salt on the abundance of nontarget organisms was also investigated in before and after style analyses. Salinities remained constant over time with little intervention. Hosts in water bodies with 4 ppt salt had a significantly lower prevalence of chytrid infection and higher survival, following metamorphosis, than hosts in 0 ppt salt. Tadpoles in the 4 ppt group were smaller in length after 1 month in the release site than those in the 0 and 2 ppt groups, but after metamorphosis body size in all water bodies was similar . In water bodies with 4 ppt salt, the abundance of dwarf tree frogs (Litoria fallax), dragonfly larvae, and damselfly larvae was lower than in water bodies with 0 and 2 ppt salt, which could have knock-on effects for community structure. Based on our results, salt may be an effective field-based B. dendrobatidis mitigation tool for lentic amphibians that could contribute to the conservation of numerous susceptible species. However, as in all conservation efforts, these benefits need to be weighed against negative effects on both target and nontarget organisms. PMID:25354647

  12. Sodium chloride inhibits the growth and infective capacity of the amphibian chytrid fungus and increases host survival rates.

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    Michelle Pirrie Stockwell

    Full Text Available The amphibian chytrid fungus Batrachochytrium dendrobatidis is a recently emerged pathogen that causes the infectious disease chytridiomycosis and has been implicated as a contributing factor in the global amphibian decline. Since its discovery, research has been focused on developing various methods of mitigating the impact of chytridiomycosis on amphibian hosts but little attention has been given to the role of antifungal agents that could be added to the host's environment. Sodium chloride is a known antifungal agent used routinely in the aquaculture industry and this study investigates its potential for use as a disease management tool in amphibian conservation. The effect of 0-5 ppt NaCl on the growth, motility and survival of the chytrid fungus when grown in culture media and its effect on the growth, infection load and survivorship of infected Peron's tree frogs (Litoria peronii in captivity, was investigated. The results reveal that these concentrations do not negatively affect the survival of the host or the pathogen. However, concentrations greater than 3 ppt significantly reduced the growth and motility of the chytrid fungus compared to 0 ppt. Concentrations of 1-4 ppt NaCl were also associated with significantly lower host infection loads while infected hosts exposed to 3 and 4 ppt NaCl were found to have significantly higher survival rates. These results support the potential for NaCl to be used as an environmentally distributed antifungal agent for the prevention of chytridiomycosis in susceptible amphibian hosts. However, further research is required to identify any negative effects of salt exposure on both target and non-target organisms prior to implementation.

  13. Substrate-specific gene expression in Batrachochytrium dendrobatidis, the chytrid pathogen of amphibians.

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    Erica Bree Rosenblum

    Full Text Available Determining the mechanisms of host-pathogen interaction is critical for understanding and mitigating infectious disease. Mechanisms of fungal pathogenicity are of particular interest given the recent outbreaks of fungal diseases in wildlife populations. Our study focuses on Batrachochytrium dendrobatidis (Bd, the chytrid pathogen responsible for amphibian declines around the world. Previous studies have hypothesized a role for several specific families of secreted proteases as pathogenicity factors in Bd, but the expression of these genes has only been evaluated in laboratory growth conditions. Here we conduct a genome-wide study of Bd gene expression under two different nutrient conditions. We compare Bd gene expression profiles in standard laboratory growth media and in pulverized host tissue (i.e., frog skin. A large proportion of genes in the Bd genome show increased expression when grown in host tissue, indicating the importance of studying pathogens on host substrate. A number of gene classes show particularly high levels of expression in host tissue, including three families of secreted proteases (metallo-, serine- and aspartyl-proteases, adhesion genes, lipase-3 encoding genes, and a group of phylogenetically unusual crinkler-like effectors. We discuss the roles of these different genes as putative pathogenicity factors and discuss what they can teach us about Bd's metabolic targets, host invasion, and pathogenesis.

  14. Amphibian Chytrid Fungus in Madagascar neither Shows Widespread Presence nor Signs of Certain Establishment.

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    Jonathan E Kolby

    Full Text Available The global spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd is associated with amphibian mass mortality, population decline, and extinction. Over the past decade, concern has been expressed for the potential introduction of Bd to Madagascar, a global hotspot of amphibian biodiversity. Following years without detection, widespread Bd presence in Madagascar has now been reported (Bletz et al. 2015a, raising international conservation concern. Before reacting to this finding with a significant management response, the accuracy and context of the data warrant cautious review. Re-examination of a 10-year dataset together with results from more recent surveillance (Kolby et al. 2015 does not yet demonstrate widespread Bd presence. Detection of Bd at "positive" locations in Madagascar has been inconsistent for unknown reasons. Whether Bd is established in Madagascar (i.e. populations are self-sustaining or instead requires continued introduction to persist also remains uncertain. The deployment of emergency conservation rescue initiatives is expected to target areas where the distribution of Bd and the risk of chytridiomycosis endangering amphibians is believed to overlap. Thus, erroneous description of Bd presence would misdirect limited conservation resources. Standardized surveillance and confirmatory surveys are now imperative to reliably characterize the distribution, potential spread, virulence and overall risk of Bd to amphibians in Madagascar.

  15. Transition of chytrid fungus infection from mouthparts to hind limbs during amphibian metamorphosis.

    Science.gov (United States)

    McMahon, Taegan A; Rohr, Jason R

    2015-03-01

    The chytrid fungus, Batrachochytrium dendrobatidis (Bd), is implicated in worldwide amphibian declines. Bd has been shown to qualitatively transition from the mouthparts of tadpoles to the hindlimbs during metamorphosis, but we lack evidence of consistency in the timing of this transition across amphibian species. We also do not have predictive functions for the abundance of Bd in mouthparts and limbs as tadpoles develop or for the relationship between keratin and Bd abundance. Hence, researchers presently have little guidance on where to sample developing amphibians to maximize Bd detection, which could affect the accuracy of prevalence and abundance estimates for this deadly pathogen. Here, we show consistency in the timing of the transition of Bd from mouthparts to hind limbs across two frog species (Osteopilus septentrionalis and Mixophyes fasciolatus). Keratin and Bd simultaneously declined from the mouthparts starting at approximately Gosner stage 40. However, keratin on the hindlimbs began to appear at approximately stage 38 but, on average, Bd was not detectable on the hindlimbs until approximately stage 40, suggesting a lag between keratin and Bd arrival. Predictive functions for the relationships between developmental stage and keratin and developmental stage and Bd for mouthparts and hind limbs are provided so that researchers can optimize sampling designs and minimize erroneous conclusions associated with missing Bd infections or misestimating Bd abundance. PMID:25384612

  16. Amphibian Chytrid Fungus in Madagascar neither Shows Widespread Presence nor Signs of Certain Establishment.

    Science.gov (United States)

    Kolby, Jonathan E; Skerratt, Lee F

    2015-01-01

    The global spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) is associated with amphibian mass mortality, population decline, and extinction. Over the past decade, concern has been expressed for the potential introduction of Bd to Madagascar, a global hotspot of amphibian biodiversity. Following years without detection, widespread Bd presence in Madagascar has now been reported (Bletz et al. 2015a), raising international conservation concern. Before reacting to this finding with a significant management response, the accuracy and context of the data warrant cautious review. Re-examination of a 10-year dataset together with results from more recent surveillance (Kolby et al. 2015) does not yet demonstrate widespread Bd presence. Detection of Bd at "positive" locations in Madagascar has been inconsistent for unknown reasons. Whether Bd is established in Madagascar (i.e. populations are self-sustaining) or instead requires continued introduction to persist also remains uncertain. The deployment of emergency conservation rescue initiatives is expected to target areas where the distribution of Bd and the risk of chytridiomycosis endangering amphibians is believed to overlap. Thus, erroneous description of Bd presence would misdirect limited conservation resources. Standardized surveillance and confirmatory surveys are now imperative to reliably characterize the distribution, potential spread, virulence and overall risk of Bd to amphibians in Madagascar. PMID:26465924

  17. Effects of the amphibian chytrid fungus and four insecticides on Pacific treefrogs (Pseudacris regilla)

    Science.gov (United States)

    Kleinhez, Peter; Boone, Michelle D.; Fellers, Gary

    2012-01-01

    Chemical contamination may influence host-pathogen interactions, which has implications for amphibian population declines. We examined the effects of four insecticides alone or as a mixture on development and metamorphosis of Pacific Treefrogs (Pseudacris regilla) in the presence or absence of the amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]). Bd exposure had a negative impact on tadpole activity, survival to metamorphosis, time to metamorphosis, and time of tail absorption (with a marginally negative effect on mass at metamorphosis); however, no individuals tested positive for Bd at metamorphosis. The presence of sublethal concentrations of insecticides alone or in a mixture did not impact Pacific Treefrog activity as tadpoles, survival to metamorphosis, or time and size to metamorphosis. Insecticide exposure did not influence the effect of Bd exposure. Our study did not support our prediction that effects of Bd would be greater in the presence of expected environmental concentrations of insecticide(s), but it did show that Bd had negative effects on responses at metamorphosis that could reduce the quality of juveniles recruited into the population.

  18. Immunomodulatory metabolites released by the frog-killing fungus Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Rollins-Smith, Louise A; Fites, J Scott; Reinert, Laura K; Shiakolas, Andrea R; Umile, Thomas P; Minbiole, Kevin P C

    2015-12-01

    Batrachochytrium dendrobatidis is a fungal pathogen in the phylum Chytridiomycota that causes the skin disease chytridiomycosis. Chytridiomycosis is considered an emerging infectious disease linked to worldwide amphibian declines and extinctions. Although amphibians have well-developed immune defenses, clearance of this pathogen from the skin is often impaired. Previously, we showed that the adaptive immune system is involved in the control of the pathogen, but B. dendrobatidis releases factors that inhibit in vitro and in vivo lymphocyte responses and induce lymphocyte apoptosis. Little is known about the nature of the inhibitory factors released by this fungus. Here, we describe the isolation and characterization of three fungal metabolites produced by B. dendrobatidis but not by the closely related nonpathogenic chytrid Homolaphlyctis polyrhiza. These metabolites are methylthioadenosine (MTA), tryptophan, and an oxidized product of tryptophan, kynurenine (Kyn). Independently, both MTA and Kyn inhibit the survival and proliferation of amphibian lymphocytes and the Jurkat human T cell leukemia cell line. However, working together, they become effective at much lower concentrations. We hypothesize that B. dendrobatidis can adapt its metabolism to release products that alter the local environment in the skin to inhibit immunity and enhance the survival of the pathogen. PMID:26371122

  19. Genome-wide transcriptional response of Silurana (Xenopus tropicalis to infection with the deadly chytrid fungus.

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    Erica Bree Rosenblum

    Full Text Available Emerging infectious diseases are of great concern for both wildlife and humans. Several highly virulent fungal pathogens have recently been discovered in natural populations, highlighting the need for a better understanding of fungal-vertebrate host-pathogen interactions. Because most fungal pathogens are not fatal in the absence of other predisposing conditions, host-pathogen dynamics for deadly fungal pathogens are of particular interest. The chytrid fungus Batrachochytrium dendrobatidis (hereafter Bd infects hundreds of species of frogs in the wild. It is found worldwide and is a significant contributor to the current global amphibian decline. However, the mechanism by which Bd causes death in amphibians, and the response of the host to Bd infection, remain largely unknown. Here we use whole-genome microarrays to monitor the transcriptional responses to Bd infection in the model frog species, Silurana (Xenopus tropicalis, which is susceptible to chytridiomycosis. To elucidate the immune response to Bd and evaluate the physiological effects of chytridiomycosis, we measured gene expression changes in several tissues (liver, skin, spleen following exposure to Bd. We detected a strong transcriptional response for genes involved in physiological processes that can help explain some clinical symptoms of chytridiomycosis at the organismal level. However, we detected surprisingly little evidence of an immune response to Bd exposure, suggesting that this susceptible species may not be mounting efficient innate and adaptive immune responses against Bd. The weak immune response may be partially explained by the thermal conditions of the experiment, which were optimal for Bd growth. However, many immune genes exhibited decreased expression in Bd-exposed frogs compared to control frogs, suggesting a more complex effect of Bd on the immune system than simple temperature-mediated immune suppression. This study generates important baseline data for ongoing

  20. Effects of amphibian chytrid fungus on individual survival probability in wild boreal toads

    Science.gov (United States)

    Pilliod, D.S.; Muths, E.; Scherer, R. D.; Bartelt, P.E.; Corn, P.S.; Hossack, B.R.; Lambert, B.A.; Mccaffery, R.; Gaughan, C.

    2010-01-01

    Chytridiomycosis is linked to the worldwide decline of amphibians, yet little is known about the demographic effects of the disease. We collected capture-recapture data on three populations of boreal toads (Bufo boreas [Bufo = Anaxyrus]) in the Rocky Mountains (U.S.A.). Two of the populations were infected with chytridiomycosis and one was not. We examined the effect of the presence of amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]; the agent of chytridiomycosis) on survival probability and population growth rate. Toads that were infected with Bd had lower average annual survival probability than uninfected individuals at sites where Bd was detected, which suggests chytridiomycosis may reduce survival by 31-42% in wild boreal toads. Toads that were negative for Bd at infected sites had survival probabilities comparable to toads at the uninfected site. Evidence that environmental covariates (particularly cold temperatures during the breeding season) influenced toad survival was weak. The number of individuals in diseased populations declined by 5-7%/year over the 6 years of the study, whereas the uninfected population had comparatively stable population growth. Our data suggest that the presence of Bd in these toad populations is not causing rapid population declines. Rather, chytridiomycosis appears to be functioning as a low-level, chronic disease whereby some infected individuals survive but the overall population effects are still negative. Our results show that some amphibian populations may be coexisting with Bd and highlight the importance of quantitative assessments of survival in diseased animal populations. Journal compilation. ?? 2010 Society for Conservation Biology. No claim to original US government works.

  1. Successful treatment of Batrachochytrium salamandrivorans infections in salamanders requires synergy between voriconazole, polymyxin E and temperature

    OpenAIRE

    Blooi, Mark; Pasmans, Frank; Rouffaer, Lieze; Haesebrouck, Freddy; Vercammen, Francis; Martel, An

    2015-01-01

    Chytridiomycosis caused by the chytrid fungus Batrachochytrium salamandrivorans (Bsal) poses a serious threat to urodelan diversity worldwide. Antimycotic treatment of this disease using protocols developed for the related fungus Batrachochytrium dendrobatidis (Bd), results in therapeutic failure. Here, we reveal that this therapeutic failure is partly due to different minimum inhibitory concentrations (MICs) of antimycotics against Bsal and Bd. In vitro growth inhibition of Bsal occurs after...

  2. Effects of temperature and hydric environment on survival of the Panamanian Golden Frog infected with a pathogenic chytrid fungus.

    Science.gov (United States)

    Bustamante, Heidi M; Livo, Lauren J; Carey, Cynthia

    2010-06-01

    Considerable controversy exists concerning whether or not climate changes (particularly global warming) are causing outbreaks of a lethal amphibian pathogen, the chytrid fungus Batrachochytrium dendrobatidis (Longcore, Pessier & D.K. Nichols 1999). In the present study, groups of Panamanian golden frogs (Atelopus zeteki Dunn, 1993), a critically endangered amphibian thought to be nearly extinct in Panama, were exposed to varying dosages of zoospores of Batrachochytrium dendrobatidis, temperatures and hydric environments in order to learn whether this species is susceptible to this pathogen and, if so, how environmental factors affect survival. This pathogen proved to be highly lethal for A. zeteki. Frogs exposed to a dosage of 100 Bd zoospores survived significantly (P<0.0001) longer than those that had been exposed to 10(4) or 10(6) zoospores. Exposed frogs housed at 23 °C survived significantly (P<0.0001) longer than those that were housed at 17 °C. Exposed frogs held in dry conditions survived significantly longer than those in wet conditions (P<0.0001). As a laboratory study, these results do not directly test hypotheses about the relation between climate change and the decline of these frogs in the field, but they inform the discussion about how environmental conditions can have an impact on the interaction between a susceptible amphibian and this pathogen. These data do not support the contention that rising global temperatures are necessary to cause the death of amphibians infected with this pathogen because the pathogen was equally lethal at 17 as at 23 °C, and frogs at the warmer temperature lived significantly longer than those at the cooler one. PMID:21392332

  3. The development of a spatially-explicit, individual-based, disease model for frogs and the chytrid fungus

    Science.gov (United States)

    Background / Question / Methods The fungal pathogen, Batrachochytrium dendrobatidis (BD), has been associated with amphibian population declines and even extinctions worldwide. Transmission of the fungus between amphibian hosts occurs via motile zoospores, which are produced on...

  4. Elevation, temperature, and aquatic connectivity all influence the infection dynamics of the amphibian chytrid fungus in adult frogs.

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    Sarah J Sapsford

    Full Text Available Infectious diseases can cause population declines and even extinctions. The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd, has caused population declines and extinctions in amphibians on most continents. In the tropics, research on the dynamics of this disease has focused on amphibian populations in mountainous areas. In most of these areas, high and low elevation sites are connected by an assemblage of streams that may transport the infectious stage of the pathogen from high to low elevations, and, also, this pathogen, which grows well at cool temperatures, may persist better in cooler water flowing from high elevations. Thus, the dynamics of disease at low elevation sites without aquatic connections to higher elevation sites, i.e., non-contiguous low elevation sites, may differ from dynamics at contiguous low elevation sites. We sampled adult common mistfrogs (Litoria rheocola at six sites of three types: two at high (> 400 m elevations, two at low elevations contiguous with high elevation streams, and two at low elevations non-contiguous with any high elevation site. Adults were swabbed for Bd diagnosis from June 2010 to June 2011 in each season, over a total of five sampling periods. The prevalence of Bd fluctuated seasonally and was highest in winter across all site types. Site type significantly affected seasonal patterns of prevalence of Bd. Prevalence remained well above zero throughout the year at the high elevation sites. Prevalence declined to lower levels in contiguous low sites, and reached near-zero at non-contiguous low sites. Patterns of air temperature fluctuation were very similar at both the low elevation site types, suggesting that differences in water connectivity to high sites may have affected the seasonal dynamics of Bd prevalence between contiguous and non-contiguous low elevation site types. Our results also suggest that reservoir hosts may be important in the persistence of disease at low elevations.

  5. Population genetics of the frog-killing fungus Batrachochytrium dendrobatidis

    OpenAIRE

    Morgan, Jess A T; Vance T Vredenburg; Rachowicz, Lara J.; Knapp, Roland A; Stice, Mary J.; Tunstall, Tate; Bingham, Rob E.; Parker, John M.; Longcore, Joyce E.; Moritz, Craig; Briggs, Cheryl J.; Taylor, John W.

    2007-01-01

    Global amphibian decline by chytridiomycosis is a major environmental disaster that has been attributed to either recent fungal spread or environmental change that promotes disease. Here, we present a population genetic comparison of Batrachochytrium dendrobatidis isolates from an intensively studied region of frog decline, the Sierra Nevada of California. In support of a novel pathogen, we find low diversity, no amphibian-host specificity, little correlation between fungal genotype and geogr...

  6. Widespread presence of the pathogenic fungus Batrachochytrium dendrobatidis in wild amphibian communities in Madagascar

    OpenAIRE

    Bletz, Molly C.; Rosa, Gonçalo M.; Andreone, Franco; Elodie A. Courtois; Schmeller, Dirk S; Nirhy H C Rabibisoa; Rabemananjara, Falitiana C. E.; Raharivololoniaina, Liliane; Vences, Miguel; Weldon, Ché; Edmonds, Devin; Raxworthy, Christopher J.; Harris, Reid N.; Fisher, Matthew C; Crottini,Angelica

    2015-01-01

    Amphibian chytridiomycosis, an emerging infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd), has been a significant driver of amphibian declines. While globally widespread, Bd had not yet been reported from within Madagascar. We document surveys conducted across the country between 2005 and 2014, showing Bd's first record in 2010. Subsequently, Bd was detected in multiple areas, with prevalence reaching up to 100%. Detection of Bd appears to be associated with mid to h...

  7. Tolerance of fungal infection in European water frogs exposed to Batrachochytrium dendrobatidis after experimental reduction of innate immune defenses

    OpenAIRE

    Woodhams Douglas C; Bigler Laurent; Marschang Rachel

    2012-01-01

    Abstract Background While emerging diseases are affecting many populations of amphibians, some populations are resistant. Determining the relative contributions of factors influencing disease resistance is critical for effective conservation management. Innate immune defenses in amphibian skin are vital host factors against a number of emerging pathogens such as ranaviruses and the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd). Adult water frogs from Switzerland (Pelophylax esc...

  8. Coqui frogs persist with the deadly chytrid fungus despite a lack of defensive antimicrobial peptides.

    Science.gov (United States)

    Rollins-Smith, Louise A; Reinert, Laura K; Burrowes, Patricia A

    2015-02-10

    The amphibian skin fungus Batrachochytrium dendrobatidis (Bd) occurs widely in Puerto Rico and is thought to be responsible for the apparent extinction of 3 species of endemic frogs in the genus Eleutherodactylus, known as coquis. To examine immune defenses which may protect surviving species, we induced secretion of skin peptides from adult common coqui frogs E. coqui collected from upland forests at El Yunque. By matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, we were unable to detect peptide signals suggestive of antimicrobial peptides, and enriched peptides showed no capacity to inhibit growth of Bd. Thus, it appears that E. coqui depend on other skin defenses to survive in the presence of this deadly fungus. PMID:25667340

  9. A Brazilian anuran (Hylodes magalhaesi: Leptodactylidae) infected by Batrachochytrium dendrobatidis: a conservation concern

    OpenAIRE

    Toledo, L. F.; Haddad, C. F. B.; Carnaval, A. C. O. Q.; F. B. Britto

    2010-01-01

    Several studies have associated the chytrid fungus Batrachochytrium dendrobatidis with anuran population declines worldwide. To date, the fungus has been found in Africa, the Americas, Australia, and Europe. However, it has never been reported to occur in the Atlantic forest or Brazil. Based on morphological, histological, and molecular data, we encountered evidence of B. dendrobatidis infection in a high-altitude stream-dwelling Brazilian anuran species, Hylodes magalhaesi (Leptodactylidae)....

  10. Quantitative Proteomics of an Amphibian Pathogen, Batrachochytrium dendrobatidis, following Exposure to Thyroid Hormone

    OpenAIRE

    Thekkiniath, Jose; Zabet-Moghaddam, Masoud; Kottapalli, Kameswara Rao; Pasham, Mithun R.; San Francisco, Susan; San Francisco, Michael

    2015-01-01

    Batrachochytrium dendrobatidis (Bd), a chytrid fungus, has increasingly been implicated as a major factor in the worldwide decline of amphibian populations. The fungus causes chytridiomycosis in susceptible species leading to massive die-offs of adult amphibians. Although Bd infects the keratinized mouthparts of tadpoles and negatively affects foraging behavior, these infections are non-lethal. An important morphogen controlling amphibian metamorphosis is thyroid hormone (T3). Tadpoles may be...

  11. Chytrid fungus acts as a generalist pathogen infecting species-rich amphibian families in Brazilian rainforests.

    Science.gov (United States)

    Valencia-Aguilar, Anyelet; Ruano-Fajardo, Gustavo; Lambertini, Carolina; da Silva Leite, Domingos; Toledo, Luís Felipe; Mott, Tamí

    2015-05-11

    The fungus Batrachochytrium dendrobatidis (Bd) is among the main causes of declines in amphibian populations. This fungus is considered a generalist pathogen because it infects several species and spreads rapidly in the wild. To date, Bd has been detected in more than 100 anuran species in Brazil, mostly in the southern portion of the Atlantic forest. Here, we report survey data from some poorly explored regions; these data considerably extend current information on the distribution of Bd in the northern Atlantic forest region. In addition, we tested the hypothesis that Bd is a generalist pathogen in this biome. We also report the first positive record for Bd in an anuran caught in the wild in Amazonia. In total, we screened 90 individuals (from 27 species), of which 39 individuals (from 22 species) were Bd-positive. All samples collected in Bahia (2 individuals), Pernambuco (3 individuals), Pará (1 individual), and Minas Gerais (1 individual) showed positive results for Bd. We found a positive correlation between anuran richness per family and the number of infected species in the Atlantic forest, supporting previous observations that Bd lacks strong host specificity; of 38% of the anuran species in the Atlantic forest that were tested for Bd infection, 25% showed positive results. The results of our study exemplify the pandemic and widespread nature of Bd infection in amphibians. PMID:25958806

  12. Thermoregulatory behaviour affects prevalence of chytrid fungal infection in a wild population of Panamanian golden frogs

    OpenAIRE

    Richards-Zawacki, Corinne L.

    2009-01-01

    Predicting how climate change will affect disease dynamics requires an understanding of how the environment affects host–pathogen interactions. For amphibians, global declines and extinctions have been linked to a pathogenic chytrid fungus, Batrachochytrium dendrobatidis. Using a combination of body temperature measurements and disease assays conducted before and after the arrival of B. dendrobatidis, this study tested the hypothesis that body temperature affects the prevalence of infection i...

  13. Evidence for acquisition of virulence effectors in pathogenic chytrids

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    Summers Kyle

    2011-07-01

    Full Text Available Abstract Background The decline in amphibian populations across the world is frequently linked to the infection of the chytrid fungus Batrachochytrium dendrobatidis (Bd. This is particularly perplexing because Bd was only recently discovered in 1999 and no chytrid fungus had previously been identified as a vertebrate pathogen. Results In this study, we show that two large families of known virulence effector genes, crinkler (CRN proteins and serine peptidases, were acquired by Bd from oomycete pathogens and bacteria, respectively. These two families have been duplicated after their acquisition by Bd. Additional selection analyses indicate that both families evolved under strong positive selection, suggesting that they are involved in the adaptation of Bd to its hosts. Conclusions We propose that the acquisition of virulence effectors, in combination with habitat disruption and climate change, may have driven the Bd epidemics and the decline in amphibian populations. This finding provides a starting point for biochemical investigations of chytridiomycosis.

  14. Variation in thermal performance of a widespread pathogen, the amphibian chytrid fungus Batrachochytrium dendrobatidis.

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    Lisa A Stevenson

    Full Text Available 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.

  15. Variation in Thermal Performance of a Widespread Pathogen, the Amphibian Chytrid Fungus Batrachochytrium dendrobatidis

    OpenAIRE

    Stevenson, Lisa A.; Ross A. Alford; Bell, Sara C.; Elizabeth A Roznik; Berger, Lee; David A Pike

    2013-01-01

    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, Batrachochy...

  16. Nothing a hot bath won't cure: infection rates of amphibian chytrid fungus correlate negatively with water temperature under natural field settings.

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    Matthew J Forrest

    Full Text Available Dramatic declines and extinctions of amphibian populations throughout the world have been associated with chytridiomycosis, an infectious disease caused by the pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd. Previous studies indicated that Bd prevalence correlates with cooler temperatures in the field, and laboratory experiments have demonstrated that Bd ceases growth at temperatures above 28°C. Here we investigate how small-scale variations in water temperature correlate with Bd prevalence in the wild. We sampled 221 amphibians, including 201 lowland leopard frogs (Rana [Lithobates] yavapaiensis, from 12 sites in Arizona, USA, and tested them for Bd. Amphibians were encountered in microhabitats that exhibited a wide range of water temperatures (10-50°C, including several geothermal water sources. There was a strong inverse correlation between the water temperature in which lowland leopard frogs were captured and Bd prevalence, even after taking into account the influence of year, season, and host size. In locations where Bd was known to be present, the prevalence of Bd infections dropped from 75-100% in water 30°C. A strong inverse correlation between Bd infection status and water temperature was also observed within sites. Our findings suggest that microhabitats where water temperatures exceed 30°C provide lowland leopard frogs with significant protection from Bd, which could have important implications for disease dynamics, as well as management applications.There must be quite a few things a hot bath won't cure, but I don't know many of them--Sylvia Plath, "The Bell Jar" (1963.

  17. The pathogen Batrachochytrium dendrobatidis disturbs the frog skin microbiome during a natural epidemic and experimental infection

    OpenAIRE

    Jani, Andrea J.; Cheryl J Briggs

    2014-01-01

    Animals are inhabited by communities of microbes (the microbiome) that potentially interact with pathogens. Detailed studies of microbiome–pathogen interactions in nature are rare, and even when correlations are observed, determining causal relationships is challenging. The microbiome–pathogen relationship is of particular interest in the case of Batrachochytrium dendrobatidis, a chytrid fungus that infects the skin of amphibians and is causing amphibian declines worldwide. We documented a st...

  18. Global gene expression profiles for life stages of the deadly amphibian pathogen Batrachochytrium dendrobatidis

    OpenAIRE

    Rosenblum, Erica Bree; Stajich, Jason E.; Maddox, Nicole; Eisen, Michael B

    2008-01-01

    Amphibians around the world are being threatened by an emerging pathogen, the chytrid fungus Batrachochytrium dendrobatidis (Bd). Despite intensive ecological study in the decade since Bd was discovered, little is known about the mechanism by which Bd kills frogs. Here, we compare patterns of global gene expression in controlled laboratory conditions for the two phases of the life cycle of Bd: the free-living zoospore and the substrate-embedded sporangia. We find zoospores to be transcription...

  19. A Fungal Pathogen of Amphibians, Batrachochytrium dendrobatidis, Attenuates in Pathogenicity with In Vitro Passages

    OpenAIRE

    Langhammer, Penny F.; Lips, Karen R.; Burrowes, Patricia A.; Tunstall, Tate; Crystal M Palmer; Collins, James P.

    2013-01-01

    Laboratory investigations into the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), have accelerated recently, given the pathogen’s role in causing the global decline and extinction of amphibians. Studies in which host animals were exposed to Bd have largely assumed that lab-maintained pathogen cultures retained the infective and pathogenic properties of wild isolates. Attenuated pathogenicity is common in artificially maintained cultures of other pathogenic fungi, but to date, ...

  20. Batrachochytrium dendrobatidis infection of amphibians in the Doñana National Park, Spain

    OpenAIRE

    Hidalgo-Vila, J.; Díaz-Paniagua, Carmen; Marchand, Marc A.; Cunningham, Andrew A.

    2012-01-01

    Amphibian chytridiomycosis, caused by infection with the non-hyphal, zoosporic chytrid fungus Batrachochytrium dendrobatidis (Bd), is an emerging infectious disease recognised as a cause of recent amphibian population declines and extinctions worldwide. The Doñana National Park (DNP) is located in southwestern Spain, a country with widespread Bd infection. This protected area has a great diversity of aquatic habitats that constitute important breeding habitats for 11 native amphibian species....

  1. Batrachochytrium dendrobatidis in amphibians of Cameroon, including first records for caecilians

    OpenAIRE

    Doherty-Bone, T.M.; Gonwouo, N.L.; Hirschfeld, M; Ohst, T.; C. Weldon

    2013-01-01

    Amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has been hypothesised to be an indigenous parasite of African amphibians. In Cameroon, however, previous surveys in one region (in the northwest) failed to detect this pathogen, despite the earliest African Bd having been recorded from a frog in eastern Cameroon, plus one recent record in the far southeast. To reconcile these contrasting results, we present survey data from 12 localities across 6 regions of Cameroon from anurans (n...

  2. The effects of a fungicide and chytrid fungus on anuran larvae in aquatic mesocosms.

    Science.gov (United States)

    Hanlon, Shane M; Lynch, Kyle J; Kerby, Jacob L; Parris, Matthew J

    2015-09-01

    The amphibian disease chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), has been linked to significant amphibian declines over the past three decades. The most severe effects of the pathogen have been primarily observed in relatively pristine areas that are not affected by many anthropogenic factors.One hypothesis concerning improved amphibian persistence with Bd in disturbed landscapes is that contaminants may abate the effects of Bd on amphibians. Recent laboratory studies have shown that pesticides, specifically the fungicide thiophanate-methyl (TM), can kill Bd outside of hosts and clear Bd infections within hosts. Using aquatic mesocosms, we tested the hypothesis that TM (0.43 mg/L) would alter growth and development of Lithobates sphenocephalus (southern leopard frog) tadpoles and Bd-infection loads in infected individuals. We hypothesized that the scope of such alterations and infection clearing would be affected by aquatic community variables, specifically zooplankton. TM altered zooplankton diversity (reduced cladoceran and increased copepod and ostracod abundances) and caused mortality to all tadpoles in TM-exposed tanks. In TM-free tanks, Bd-exposed tadpoles in high-density treatments metamorphosed smaller than Bd-unexposed, effects that were reversed in low-density treatments. Our study demonstrates the potential adverse effects of a fungicide and Bd on tadpoles and aquatic systems. PMID:25913318

  3. Assessing the Threat of Amphibian Chytrid Fungus in the Albertine Rift: Past, Present and Future.

    Science.gov (United States)

    Seimon, Tracie A; Ayebare, Samuel; Sekisambu, Robert; Muhindo, Emmanuel; Mitamba, Guillain; Greenbaum, Eli; Menegon, Michele; Pupin, Fabio; McAloose, Denise; Ammazzalorso, Alyssa; Meirte, Danny; Lukwago, Wilbur; Behangana, Mathias; Seimon, Anton; Plumptre, Andrew J

    2015-01-01

    Batrachochytrium dendrobatidis (Bd), the cause of chytridiomycosis, is a pathogenic fungus that is found worldwide and is a major contributor to amphibian declines and extinctions. We report results of a comprehensive effort to assess the distribution and threat of Bd in one of the Earth's most important biodiversity hotspots, the Albertine Rift in central Africa. In herpetological surveys conducted between 2010 and 2014, 1018 skin swabs from 17 amphibian genera in 39 sites across the Albertine Rift were tested for Bd by PCR. Overall, 19.5% of amphibians tested positive from all sites combined. Skin tissue samples from 163 amphibians were examined histologically; of these two had superficial epidermal intracorneal fungal colonization and lesions consistent with the disease chytridiomycosis. One amphibian was found dead during the surveys, and all others encountered appeared healthy. We found no evidence for Bd-induced mortality events, a finding consistent with other studies. To gain a historical perspective about Bd in the Albertine Rift, skin swabs from 232 museum-archived amphibians collected as voucher specimens from 1925-1994 were tested for Bd. Of these, one sample was positive; an Itombwe River frog (Phrynobatrachus asper) collected in 1950 in the Itombwe highlands. This finding represents the earliest record of Bd in the Democratic Republic of Congo. We modeled the distribution of Bd in the Albertine Rift using MaxEnt software, and trained our model for improved predictability. Our model predicts that Bd is currently widespread across the Albertine Rift, with moderate habitat suitability extending into the lowlands. Under climatic modeling scenarios our model predicts that optimal habitat suitability of Bd will decrease causing a major range contraction of the fungus by 2080. Our baseline data and modeling predictions are important for comparative studies, especially if significant changes in amphibian health status or climactic conditions are encountered

  4. Assessing the Threat of Amphibian Chytrid Fungus in the Albertine Rift: Past, Present and Future.

    Directory of Open Access Journals (Sweden)

    Tracie A Seimon

    Full Text Available Batrachochytrium dendrobatidis (Bd, the cause of chytridiomycosis, is a pathogenic fungus that is found worldwide and is a major contributor to amphibian declines and extinctions. We report results of a comprehensive effort to assess the distribution and threat of Bd in one of the Earth's most important biodiversity hotspots, the Albertine Rift in central Africa. In herpetological surveys conducted between 2010 and 2014, 1018 skin swabs from 17 amphibian genera in 39 sites across the Albertine Rift were tested for Bd by PCR. Overall, 19.5% of amphibians tested positive from all sites combined. Skin tissue samples from 163 amphibians were examined histologically; of these two had superficial epidermal intracorneal fungal colonization and lesions consistent with the disease chytridiomycosis. One amphibian was found dead during the surveys, and all others encountered appeared healthy. We found no evidence for Bd-induced mortality events, a finding consistent with other studies. To gain a historical perspective about Bd in the Albertine Rift, skin swabs from 232 museum-archived amphibians collected as voucher specimens from 1925-1994 were tested for Bd. Of these, one sample was positive; an Itombwe River frog (Phrynobatrachus asper collected in 1950 in the Itombwe highlands. This finding represents the earliest record of Bd in the Democratic Republic of Congo. We modeled the distribution of Bd in the Albertine Rift using MaxEnt software, and trained our model for improved predictability. Our model predicts that Bd is currently widespread across the Albertine Rift, with moderate habitat suitability extending into the lowlands. Under climatic modeling scenarios our model predicts that optimal habitat suitability of Bd will decrease causing a major range contraction of the fungus by 2080. Our baseline data and modeling predictions are important for comparative studies, especially if significant changes in amphibian health status or climactic conditions

  5. Effects of Pesticide Mixtures on Host-Pathogen Dynamics of the Amphibian Chytrid Fungus

    Science.gov (United States)

    Buck, Julia C.; Hua, Jessica; Brogan, William R.; Dang, Trang D.; Urbina, Jenny; Bendis, Randall J.; Stoler, Aaron B.; Blaustein, Andrew R.; Relyea, Rick A.

    2015-01-01

    Anthropogenic and natural stressors often interact to affect organisms. Amphibian populations are undergoing unprecedented declines and extinctions with pesticides and emerging infectious diseases implicated as causal factors. Although these factors often co-occur, their effects on amphibians are usually examined in isolation. We hypothesized that exposure of larval and metamorphic amphibians to ecologically relevant concentrations of pesticide mixtures would increase their post-metamorphic susceptibility to the fungus Batrachochytrium dendrobatidis (Bd), a pathogen that has contributed to amphibian population declines worldwide. We exposed five anuran species (Pacific treefrog, Pseudacris regilla; spring peeper, Pseudacris crucifer; Cascades frog, Rana cascadae; northern leopard frog, Lithobates pipiens; and western toad, Anaxyrus boreas) from three families to mixtures of four common insecticides (chlorpyrifos, carbaryl, permethrin, and endosulfan) or herbicides (glyphosate, acetochlor, atrazine, and 2,4-D) or a control treatment, either as tadpoles or as newly metamorphic individuals (metamorphs). Subsequently, we exposed animals to Bd or a control inoculate after metamorphosis and compared survival and Bd load. Bd exposure significantly increased mortality in Pacific treefrogs, spring peepers, and western toads, but not in Cascades frogs or northern leopard frogs. However, the effects of pesticide exposure on mortality were negligible, regardless of the timing of exposure. Bd load varied considerably across species; Pacific treefrogs, spring peepers, and western toads had the highest loads, whereas Cascades frogs and northern leopard frogs had the lowest loads. The influence of pesticide exposure on Bd load depended on the amphibian species, timing of pesticide exposure, and the particular pesticide treatment. Our results suggest that exposure to realistic pesticide concentrations has minimal effects on Bd-induced mortality, but can alter Bd load. This result

  6. Effects of Pesticide Mixtures on Host-Pathogen Dynamics of the Amphibian Chytrid Fungus.

    Directory of Open Access Journals (Sweden)

    Julia C Buck

    Full Text Available Anthropogenic and natural stressors often interact to affect organisms. Amphibian populations are undergoing unprecedented declines and extinctions with pesticides and emerging infectious diseases implicated as causal factors. Although these factors often co-occur, their effects on amphibians are usually examined in isolation. We hypothesized that exposure of larval and metamorphic amphibians to ecologically relevant concentrations of pesticide mixtures would increase their post-metamorphic susceptibility to the fungus Batrachochytrium dendrobatidis (Bd, a pathogen that has contributed to amphibian population declines worldwide. We exposed five anuran species (Pacific treefrog, Pseudacris regilla; spring peeper, Pseudacris crucifer; Cascades frog, Rana cascadae; northern leopard frog, Lithobates pipiens; and western toad, Anaxyrus boreas from three families to mixtures of four common insecticides (chlorpyrifos, carbaryl, permethrin, and endosulfan or herbicides (glyphosate, acetochlor, atrazine, and 2,4-D or a control treatment, either as tadpoles or as newly metamorphic individuals (metamorphs. Subsequently, we exposed animals to Bd or a control inoculate after metamorphosis and compared survival and Bd load. Bd exposure significantly increased mortality in Pacific treefrogs, spring peepers, and western toads, but not in Cascades frogs or northern leopard frogs. However, the effects of pesticide exposure on mortality were negligible, regardless of the timing of exposure. Bd load varied considerably across species; Pacific treefrogs, spring peepers, and western toads had the highest loads, whereas Cascades frogs and northern leopard frogs had the lowest loads. The influence of pesticide exposure on Bd load depended on the amphibian species, timing of pesticide exposure, and the particular pesticide treatment. Our results suggest that exposure to realistic pesticide concentrations has minimal effects on Bd-induced mortality, but can alter Bd load

  7. First record of the chytrid fungus in Lithobates catesbeianus from Argentina: exotic species and conservation Primer registro del hongo quitridio en Lithobates catesbeianus de Argentina: especies exóticas y conservación

    Directory of Open Access Journals (Sweden)

    Romina Ghirardi

    2011-12-01

    Full Text Available Chytridiomycosis, a disease caused by the chytrid fungus Batrachochytrium dendrobatidis (B.d., is recognized as one of the major factors of amphibian decline. Global trade of amphibians has been identified as one of the causes of B.d. spread, involving hundreds of species world wide. In this work we detected the presence of B.d. through histological examination on 5 out of 9 analyzed specimens of bullfrogs (Lithobates catesbeianus from a farm in Santa Fe City (Argentina, deposited since 1993 in the herpetological collection of the Provincial Museum of Natural Sciences "Florentino Ameghino". Our finding represents the oldest record of B.d. for Argentina and the first case of the chytrid fungus infecting the exotic bullfrog in this country. We emphasize the importance of determining and monitoring the distribution and spread of B.d in Argentina, particularly in areas where feral bullfrog populations have already been identified.La quitridiomicosis, enfermedad emergente producida por el hongo Batrachochytrium dendrobatidis (B.d., es reconocida como uno de los factores causantes de la declinación de anfibios. El comercio mundial de anfibios ha sido señalado como una de las fuentes de dispersión de B.d. En este trabajo se detectó la presencia de B.d. en la especie exótica rana toro (Lithobates catesbeianus mediante cortes histológicos en 5 de 9 ejemplares provenientes de un criadero de la ciudad de Santa Fe (Argentina, depositados y conservados desde 1993 en la Colección Herpetológica del Museo Provincial de Ciencias Naturales "Florentino Ameghino". Este registro representa el hallazgo más antiguo de B.d. en Argentina y el primer caso de este hongo en la rana toro exótica en el país; por lo que enfatizamos la importancia de determinar y monitorear la distribución y dispersión de B.d., particularmente en los sitios donde ya se han detectado poblaciones silvestres de rana toro.

  8. Field and Laboratory Studies of the Susceptibility of the Green Treefrog (Hyla cinerea) to Batrachochytrium dendrobatidis Infection

    OpenAIRE

    Laura A Brannelly; Chatfield, Matthew W. H.; Richards-Zawacki, Corinne L.

    2012-01-01

    Amphibians worldwide are experiencing devastating declines, some of which are due to the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd). Populations in the southeastern United States, however, have not been noticeably affected by the pathogen. The green treefrog (Hyla cinerea) is abundant and widespread in the southeastern United States, but has not been documented to harbor Bd infection. This study examined the susceptibility of H. cinerea to two strains of Bd in the lab and t...

  9. Widespread presence of the pathogenic fungus Batrachochytrium dendrobatidis in wild amphibian communities in Madagascar.

    Science.gov (United States)

    Bletz, Molly C; Rosa, Gonçalo M; Andreone, Franco; Courtois, Elodie A; Schmeller, Dirk S; Rabibisoa, Nirhy H C; Rabemananjara, Falitiana C E; Raharivololoniaina, Liliane; Vences, Miguel; Weldon, Ché; Edmonds, Devin; Raxworthy, Christopher J; Harris, Reid N; Fisher, Matthew C; Crottini, Angelica

    2015-01-01

    Amphibian chytridiomycosis, an emerging infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd), has been a significant driver of amphibian declines. While globally widespread, Bd had not yet been reported from within Madagascar. We document surveys conducted across the country between 2005 and 2014, showing Bd's first record in 2010. Subsequently, Bd was detected in multiple areas, with prevalence reaching up to 100%. Detection of Bd appears to be associated with mid to high elevation sites and to have a seasonal pattern, with greater detectability during the dry season. Lineage-based PCR was performed on a subset of samples. While some did not amplify with any lineage probe, when a positive signal was observed, samples were most similar to the Global Panzootic Lineage (BdGPL). These results may suggest that Bd arrived recently, but do not exclude the existence of a previously undetected endemic Bd genotype. Representatives of all native anuran families have tested Bd-positive, and exposure trials confirm infection by Bd is possible. Bd's presence could pose significant threats to Madagascar's unique "megadiverse" amphibians. PMID:25719857

  10. Heterogeneous occupancy and density estimates of the pathogenic fungus Batrachochytrium dendrobatidis in waters of North America.

    Directory of Open Access Journals (Sweden)

    Tara Chestnut

    Full Text Available Biodiversity losses are occurring worldwide due to a combination of stressors. For example, by one estimate, 40% of amphibian species are vulnerable to extinction, and disease is one threat to amphibian populations. The emerging infectious disease chytridiomycosis, caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd, is a contributor to amphibian declines worldwide. Bd research has focused on the dynamics of the pathogen in its amphibian hosts, with little emphasis on investigating the dynamics of free-living Bd. Therefore, we investigated patterns of Bd occupancy and density in amphibian habitats using occupancy models, powerful tools for estimating site occupancy and detection probability. Occupancy models have been used to investigate diseases where the focus was on pathogen occurrence in the host. We applied occupancy models to investigate free-living Bd in North American surface waters to determine Bd seasonality, relationships between Bd site occupancy and habitat attributes, and probability of detection from water samples as a function of the number of samples, sample volume, and water quality. We also report on the temporal patterns of Bd density from a 4-year case study of a Bd-positive wetland. We provide evidence that Bd occurs in the environment year-round. Bd exhibited temporal and spatial heterogeneity in density, but did not exhibit seasonality in occupancy. Bd was detected in all months, typically at less than 100 zoospores L(-1. The highest density observed was ∼3 million zoospores L(-1. We detected Bd in 47% of sites sampled, but estimated that Bd occupied 61% of sites, highlighting the importance of accounting for imperfect detection. When Bd was present, there was a 95% chance of detecting it with four samples of 600 ml of water or five samples of 60 mL. Our findings provide important baseline information to advance the study of Bd disease ecology, and advance our understanding of amphibian exposure to free

  11. Heterogeneous occupancy and density estimates of the pathogenic fungus Batrachochytrium dendrobatidis in waters of North America

    Science.gov (United States)

    Chestnut, Tara E.; Anderson, Chauncey; Popa, Radu; Blaustein, Andrew R.; Voytek, Mary; Olson, Deanna H.; Kirshtein, Julie

    2014-01-01

    Biodiversity losses are occurring worldwide due to a combination of stressors. For example, by one estimate, 40% of amphibian species are vulnerable to extinction, and disease is one threat to amphibian populations. The emerging infectious disease chytridiomycosis, caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd), is a contributor to amphibian declines worldwide. Bd research has focused on the dynamics of the pathogen in its amphibian hosts, with little emphasis on investigating the dynamics of free-living Bd. Therefore, we investigated patterns of Bd occupancy and density in amphibian habitats using occupancy models, powerful tools for estimating site occupancy and detection probability. Occupancy models have been used to investigate diseases where the focus was on pathogen occurrence in the host. We applied occupancy models to investigate free-living Bd in North American surface waters to determine Bd seasonality, relationships between Bd site occupancy and habitat attributes, and probability of detection from water samples as a function of the number of samples, sample volume, and water quality. We also report on the temporal patterns of Bd density from a 4-year case study of a Bd-positive wetland. We provide evidence that Bd occurs in the environment year-round. Bd exhibited temporal and spatial heterogeneity in density, but did not exhibit seasonality in occupancy. Bd was detected in all months, typically at less than 100 zoospores L−1. The highest density observed was ∼3 million zoospores L−1. We detected Bd in 47% of sites sampled, but estimated that Bd occupied 61% of sites, highlighting the importance of accounting for imperfect detection. When Bd was present, there was a 95% chance of detecting it with four samples of 600 ml of water or five samples of 60 mL. Our findings provide important baseline information to advance the study of Bd disease ecology, and advance our understanding of amphibian exposure to free-living Bd in aquatic

  12. Inhibition of Batrachochytrium dendrobatidis Caused by Bacteria Isolated from the Skin of Boreal Toads, Anaxyrus (Bufo) boreas boreas, from Grand Teton National Park, Wyoming, USA

    OpenAIRE

    Park, Shawna T; Collingwood, Amanda M; Sophie St-Hilaire; Sheridan, Peter P.

    2014-01-01

    The chytrid fungus Batrachochytrium dendrobatidis is a significant cause of the worldwide decline in amphibian populations; however, various amphibian species are capable of coexisting with B. dendrobatidis. Among them are boreal toads (Anaxyrus (Bufo) boreas boreas) located in Grand Teton National Park (GTNP) in Wyoming, USA. The purpose of this study was to identify cultivable bacterial isolates from the skin microbiota of boreal toads from GTNP and determine if they were capable of inhibit...

  13. Endangered Frogs Coexist with Fungus Once Thought Fatal

    OpenAIRE

    Retallick, Richard W. R; Hamish McCallum; Rick Speare

    2004-01-01

    The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of numerous frog species worldwide. In Queensland, Australia, it has been proposed as the cause of the decline or apparent extinction of at least 14 high-elevation rainforest frog species. One of these, Taudactylus eungellensis, disappeared from rainforest streams in Eungella National Park in 1985-1986, but a few remnant populations were subsequently discovered. Here, we report the analysis of ...

  14. Community Structure and Function of Amphibian Skin Microbes: An Experiment with Bullfrogs Exposed to a Chytrid Fungus.

    Science.gov (United States)

    Walke, Jenifer B; Becker, Matthew H; Loftus, Stephen C; House, Leanna L; Teotonio, Thais L; Minbiole, Kevin P C; Belden, Lisa K

    2015-01-01

    The vertebrate microbiome contributes to disease resistance, but few experiments have examined the link between microbiome community structure and disease resistance functions. Chytridiomycosis, a major cause of amphibian population declines, is a skin disease caused by the fungus, Batrachochytrium dendrobatidis (Bd). In a factorial experiment, bullfrog skin microbiota was reduced with antibiotics, augmented with an anti-Bd bacterial isolate (Janthinobacterium lividum), or unmanipulated, and individuals were then either exposed or not exposed to Bd. We found that the microbial community structure of individual frogs prior to Bd exposure influenced Bd infection intensity one week following exposure, which, in turn, was negatively correlated with proportional growth during the experiment. Microbial community structure and function differed among unmanipulated, antibiotic-treated, and augmented frogs only when frogs were exposed to Bd. Bd is a selective force on microbial community structure and function, and beneficial states of microbial community structure may serve to limit the impacts of infection. PMID:26445500

  15. Community Structure and Function of Amphibian Skin Microbes: An Experiment with Bullfrogs Exposed to a Chytrid Fungus.

    Directory of Open Access Journals (Sweden)

    Jenifer B Walke

    Full Text Available The vertebrate microbiome contributes to disease resistance, but few experiments have examined the link between microbiome community structure and disease resistance functions. Chytridiomycosis, a major cause of amphibian population declines, is a skin disease caused by the fungus, Batrachochytrium dendrobatidis (Bd. In a factorial experiment, bullfrog skin microbiota was reduced with antibiotics, augmented with an anti-Bd bacterial isolate (Janthinobacterium lividum, or unmanipulated, and individuals were then either exposed or not exposed to Bd. We found that the microbial community structure of individual frogs prior to Bd exposure influenced Bd infection intensity one week following exposure, which, in turn, was negatively correlated with proportional growth during the experiment. Microbial community structure and function differed among unmanipulated, antibiotic-treated, and augmented frogs only when frogs were exposed to Bd. Bd is a selective force on microbial community structure and function, and beneficial states of microbial community structure may serve to limit the impacts of infection.

  16. Populations of a susceptible amphibian species can grow despite the presence of a pathogenic chytrid fungus.

    Directory of Open Access Journals (Sweden)

    Ursina Tobler

    Full Text Available Disease can be an important driver of host population dynamics and epizootics can cause severe host population declines. Batrachochytrium dendrobatidis (Bd, the pathogen causing amphibian chytridiomycosis, may occur epizootically or enzootically and can harm amphibian populations in many ways. While effects of Bd epizootics are well documented, the effects of enzootic Bd have rarely been described. We used a state-space model that accounts for observation error to test whether population trends of a species highly susceptible to Bd, the midwife toad Alytes obstetricans, are negatively affected by the enzootic presence of the pathogen. Unexpectedly, Bd had no negative effect on population growth rates from 2002-2008. This suggests that negative effects of disease on individuals do not necessarily translate into negative effects at the population level. Populations of amphibian species that are susceptible to the emerging disease chytridiomycosis can persist despite the enzootic presence of the pathogen under current environmental conditions.

  17. Enhanced call effort in Japanese tree frogs infected by amphibian chytrid fungus.

    Science.gov (United States)

    An, Deuknam; Waldman, Bruce

    2016-03-01

    Some amphibians have evolved resistance to the devastating disease chytridiomycosis, associated with global population declines, but immune defences can be costly. We recorded advertisement calls of male Japanese tree frogs (Hyla japonica) in the field. We then assessed whether individuals were infected by Batrachochytrium dendrobatidis (Bd), the causal agent of the disease. This allowed us to analyse call properties of males as a function of their infection status. Infected males called more rapidly and produced longer calls than uninfected males. This enhanced call effort may reflect pathogen manipulation of host behaviour to foster disease transmission. Alternatively, increased calling may have resulted from selection on infected males to reproduce earlier because of their shortened expected lifespan. Our results raise the possibility that sublethal effects of Bd alter amphibian life histories, which contributes to long-term population declines. PMID:26932682

  18. Effects of an Infectious Fungus, Batrachochytrium dendrobatidis, on Amphibian Predator-Prey Interactions

    OpenAIRE

    Han, Barbara A; Catherine L Searle; BLAUSTEIN, ANDREW R.

    2011-01-01

    The effects of parasites and pathogens on host behaviors may be particularly important in predator-prey contexts, since few animal behaviors are more crucial for ensuring immediate survival than the avoidance of lethal predators in nature. We examined the effects of an emerging fungal pathogen of amphibians, Batrachochytrium dendrobatidis, on anti-predator behaviors of tadpoles of four frog species. We also investigated whether amphibian predators consumed infected prey, and whether B. dendro...

  19. Short term minimum water temperatures determine levels of infection by the amphibian chytrid fungus in Alytes obstetricans tadpoles.

    Directory of Open Access Journals (Sweden)

    Saioa Fernández-Beaskoetxea

    Full Text Available Amphibians are one of the groups of wildlife most seriously threatened by emerging infectious disease. In particular, chytridiomycosis, caused by the aquatic fungus Batrachochytrium dendrobatidis, is responsible for amphibian species declines on a worldwide scale. Population-level outcomes following the introduction of the pathogen are context dependent and mediated by a large suite of abiotic and biotic variables. In particular, studies have shown that temperature has a key role in determining infection dynamics owing to the ectothermic nature of the amphibian host and temperature-dependency of pathogen growth rates. To assess the temperature-dependent seasonality of infectious burdens in a susceptible host species, we monitored lowland populations of larval midwife toads, Alytes obstetricians, in Central Spain throughout the year. We found that infections were highly seasonal, and inversely correlated against water temperature, with the highest burdens of infection seen during the colder months. Short-term impacts of water-temperature were found, with the minimum temperatures occurring before sampling being more highly predictive of infectious burdens than were longer-term spans of temperature. Our results will be useful for selecting the optimal time for disease surveys and, more broadly, for determining the key periods to undertake disease mitigation.

  20. Amphibian pathogens at northern latitudes: presence of chytrid fungus and ranavirus in northeastern Canada.

    Science.gov (United States)

    D'Aoust-Messier, Andrée-Michelle; Echaubard, Pierre; Billy, Vincent; Lesbarrères, David

    2015-03-01

    Infections by the fungal pathogen Batrachochytrium dendrobatidis (Bd) and members of the genus Ranavirus (Rv) are increasingly reported as significant determinants of amphibian population die-offs. The complexity associated with their transmission and spatial distribution leads to an increase in demand for comprehensive reporting systems and global mapping of their distribution. Here, we document the distribution of these 2 pathogens in a remote northern temperate lowland where environmental sensitivity is high, providing important insight into the pathogens' natural history and infection patterns. Wood frog Lithobates sylvaticus tissues were collected from the James Bay area in northeastern Canada and were screened for the presence of Bd and Rv using conventional and real-time PCR. Both pathogens were present in the study area, which is the northernmost record in eastern North America. Interestingly, different patterns of distribution were observed between the eastern and western coasts of James Bay, suggesting differences in the spatial and transmission dynamics for each pathogen. Anthropogenic introduction may still influence the distribution patterns observed, even at these latitudes. The presence of infections in this remote area also raises further questions on the risk these pathogens pose to northern amphibian communities. We encourage further research in remote locations for a better understanding of these pathogens, their transmission dynamics, and especially their respective impacts on amphibian populations worldwide. PMID:25751857

  1. Spread of Amphibian Chytrid Fungus across Lowland Populations of Tungara Frogs in Panama.

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    Sofía Rodríguez-Brenes

    Full Text Available Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd, is an emergent infectious disease partially responsible for worldwide amphibian population declines. The spread of Bd along highland habitats (> 500 meters above sea level, m a.s.l. of Costa Rica and Panamá is well documented and has been linked to amphibian population collapses. In contrast, data are scarce on the prevalence and dispersal of Bd in lowland habitats where amphibians may be infected but asymptomatic. Here we describe the spread (2009 to 2014 of Bd across lowland habitats east of the Panamá Canal (< 500 m a.s.l. with a focus on the Túngara frog (Physalaemus [Engystomops] pustulosus, one of the most common and abundant frog species in this region. Highland populations in western Panamá were already infected with Bd at the start of the study, which was consistent with previous studies indicating that Bd is enzootic in this region. In central Panamá, we collected the first positive samples in 2010, and by 2014, we detected Bd from remote sites in eastern Panamá (Darién National Park. We discuss the importance of studying Bd in lowland species, which may serve as potential reservoirs and agents of dispersal of Bd to highland species that are more susceptible to chytridiomycosis.

  2. Spread of Amphibian Chytrid Fungus across Lowland Populations of Túngara Frogs in Panamá.

    Science.gov (United States)

    Rodríguez-Brenes, Sofía; Rodriguez, David; Ibáñez, Roberto; Ryan, Michael J

    2016-01-01

    Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is an emergent infectious disease partially responsible for worldwide amphibian population declines. The spread of Bd along highland habitats (> 500 meters above sea level, m a.s.l.) of Costa Rica and Panamá is well documented and has been linked to amphibian population collapses. In contrast, data are scarce on the prevalence and dispersal of Bd in lowland habitats where amphibians may be infected but asymptomatic. Here we describe the spread (2009 to 2014) of Bd across lowland habitats east of the Panamá Canal (< 500 m a.s.l.) with a focus on the Túngara frog (Physalaemus [Engystomops] pustulosus), one of the most common and abundant frog species in this region. Highland populations in western Panamá were already infected with Bd at the start of the study, which was consistent with previous studies indicating that Bd is enzootic in this region. In central Panamá, we collected the first positive samples in 2010, and by 2014, we detected Bd from remote sites in eastern Panamá (Darién National Park). We discuss the importance of studying Bd in lowland species, which may serve as potential reservoirs and agents of dispersal of Bd to highland species that are more susceptible to chytridiomycosis. PMID:27176629

  3. Spread of Amphibian Chytrid Fungus across Lowland Populations of Túngara Frogs in Panamá

    Science.gov (United States)

    Rodríguez-Brenes, Sofía; Rodriguez, David; Ibáñez, Roberto; Ryan, Michael J.

    2016-01-01

    Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is an emergent infectious disease partially responsible for worldwide amphibian population declines. The spread of Bd along highland habitats (> 500 meters above sea level, m a.s.l.) of Costa Rica and Panamá is well documented and has been linked to amphibian population collapses. In contrast, data are scarce on the prevalence and dispersal of Bd in lowland habitats where amphibians may be infected but asymptomatic. Here we describe the spread (2009 to 2014) of Bd across lowland habitats east of the Panamá Canal (< 500 m a.s.l.) with a focus on the Túngara frog (Physalaemus [Engystomops] pustulosus), one of the most common and abundant frog species in this region. Highland populations in western Panamá were already infected with Bd at the start of the study, which was consistent with previous studies indicating that Bd is enzootic in this region. In central Panamá, we collected the first positive samples in 2010, and by 2014, we detected Bd from remote sites in eastern Panamá (Darién National Park). We discuss the importance of studying Bd in lowland species, which may serve as potential reservoirs and agents of dispersal of Bd to highland species that are more susceptible to chytridiomycosis. PMID:27176629

  4. The Bacterially Produced Metabolite Violacein Is Associated with Survival of Amphibians Infected with a Lethal Fungus

    OpenAIRE

    Matthew H Becker; Brucker, Robert M.; Schwantes, Christian R.; Harris, Reid N.; Minbiole, Kevin P. C.

    2009-01-01

    The disease chytridiomycosis, which is caused by the chytrid fungus Batrachochytrium dendrobatidis, is associated with recent declines in amphibian populations. Susceptibility to this disease varies among amphibian populations and species, and resistance appears to be attributable in part to the presence of antifungal microbial species associated with the skin of amphibians. The betaproteobacterium Janthinobacterium lividum has been isolated from the skins of several amphibian species and pro...

  5. Effects of an infectious fungus, Batrachochytrium dendrobatidis, on amphibian predator-prey interactions.

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    Barbara A Han

    Full Text Available The effects of parasites and pathogens on host behaviors may be particularly important in predator-prey contexts, since few animal behaviors are more crucial for ensuring immediate survival than the avoidance of lethal predators in nature. We examined the effects of an emerging fungal pathogen of amphibians, Batrachochytrium dendrobatidis, on anti-predator behaviors of tadpoles of four frog species. We also investigated whether amphibian predators consumed infected prey, and whether B. dendrobatidis caused differences in predation rates among prey in laboratory feeding trials. We found differences in anti-predator behaviors among larvae of four amphibian species, and show that infected tadpoles of one species (Anaxyrus boreas were more active and sought refuge more frequently when exposed to predator chemical cues. Salamander predators consumed infected and uninfected tadpoles of three other prey species at similar rates in feeding trials, and predation risk among prey was unaffected by B. dendrobatidis. Collectively, our results show that even sub-lethal exposure to B. dendrobatidis can alter fundamental anti-predator behaviors in some amphibian prey species, and suggest the unexplored possibility that indiscriminate predation between infected and uninfected prey (i.e., non-selective predation could increase the prevalence of this widely distributed pathogen in amphibian populations. Because one of the most prominent types of predators in many amphibian systems is salamanders, and because salamanders are susceptible to B. dendrobatidis, our work suggests the importance of considering host susceptibility and behavioral changes that could arise from infection in both predators and prey.

  6. The lethal fungus Batrachochytrium dendrobatidis is present in lowland tropical forests of far eastern Panama.

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    Eria A Rebollar

    Full Text Available The fungal disease chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd, is one of the main causes of amphibian population declines and extinctions all over the world. In the Neotropics, this fungal disease has caused catastrophic declines in the highlands as it has spread throughout Central America down to Panamá. In this study, we determined the prevalence and intensity of Bd infection in three species of frogs in one highland and four lowland tropical forests, including two lowland regions in eastern Panamá in which the pathogen had not been detected previously. Bd was present in all the sites sampled with a prevalence ranging from 15-34%, similar to other Neotropical lowland sites. The intensity of Bd infection on individual frogs was low, ranging from average values of 0.11-24 zoospore equivalents per site. Our work indicates that Bd is present in anuran communities in lowland Panamá, including the Darién province, and that the intensity of the infection may vary among species from different habitats and with different life histories. The population-level consequences of Bd infection in amphibian communities from the lowlands remain to be determined. Detailed studies of amphibian species from the lowlands will be essential to determine the reason why these species are persisting despite the presence of the pathogen.

  7. Cardiac adaptations of bullfrog tadpoles in response to chytrid infection.

    Science.gov (United States)

    Salla, Raquel Fernanda; Gamero, Fernando Urban; Ribeiro, Larissa Rodrigues; Rizzi, Gisele Miglioranza; Medico, Samuel Espinosa Dal; Rissoli, Rafael Zanelli; Vieira, Conrado Augusto; Silva-Zacarin, Elaine Cristina Mathias; Leite, Domingos Silva; Abdalla, Fábio Camargo; Toledo, Luis Felipe; Costa, Monica Jones

    2015-08-01

    The chytrid fungus Batrachochytrium dendrobatidis (Bd) can result in heart failure in Bd-susceptible species. Since Bd infection generally does not cause mortality in North American bullfrogs, the aim of this work was to verify whether this species presents any cardiac adaptation that could improve the tolerance to the fungus. Thus, we analyzed tadpoles' activity level, relative ventricular mass, ventricle morphology, in loco heart frequency, and in vitro cardiac function. The results indicate that infected animals present an increase in both ventricular relative mass and in myofibrils' incidence, which accompanied the increase in myocytes' diameter. Such morphological alterations enabled an increase in the in vitro twitch force that, in vivo, would result in elevation of the cardiac stroke volume. This response requires much less energy expenditure than an elevation in heart frequency, but still enables the heart to pump a higher volume of blood per minute (i.e., an increase in cardiac output). As a consequence, the energy saved in the regulation of the cardiac function of Bd-infected tadpoles can be employed in other homeostatic adjustments to avoid the lethal effect of the fungus. Whether other species present this ability, and to what extent, remains uncertain, but such possible interspecific variability might explain different mortality rates among different species of Bd-infected amphibians. PMID:26055358

  8. The Lethal Fungus Batrachochytrium dendrobatidis Is Present in Lowland Tropical Forests of Far Eastern Panamá

    OpenAIRE

    Eria A Rebollar; Myra C. Hughey; Harris, Reid N.; Domangue, Rickie J; Daniel Medina; Roberto Ibáñez; Lisa K Belden

    2014-01-01

    The fungal disease chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), is one of the main causes of amphibian population declines and extinctions all over the world. In the Neotropics, this fungal disease has caused catastrophic declines in the highlands as it has spread throughout Central America down to Panamá. In this study, we determined the prevalence and intensity of Bd infection in three species of frogs in one highland and four lowland tropical forests, including two lowl...

  9. Batrachochytrium salamandrivorans sp nov causes lethal chytridiomycosis in amphibians

    OpenAIRE

    Martel, An; Spitzen - van der Sluijs, Annemarieke; Blooi, Mark; Bert, Wim; Ducatelle, Richard; Fisher, Matthew C; Woeltjes, Antonius; Bosman, Wilbert; Chiers, Koen; Bossuyt, Franky; Pasmans, Frank

    2013-01-01

    Chytridiomycosis has resulted in the serious decline and extinction of >200 species of amphibians worldwide and poses the greatest threat to biodiversity of any known disease. This fungal disease is currently known to be caused by Batrachochytrium dendrobatidis, hitherto the only species within the entire phylum of the Chytridiomycota known to parasitize vertebrate hosts. We describe the discovery of a second highly divergent, chytrid pathogen, Batrachochytrium salamandrivorans sp. nov., that...

  10. The amphibian pathogen Batrachochytrium dendrobatidis detected in a community of stream and wetland amphibians

    Science.gov (United States)

    Grant, E.H.C.; Bailey, L.L.; Ware, J.L.; Duncan, K.C.

    2008-01-01

    The amphibian chytrid fungus Batrachochytrium dendrobatidis, responsible for the potentially fatal amphibian disease chytridiomycosis, is known to occur in a large and ever increasing number of amphibian populations around the world. However, sampling has been biased towards stream- and wetland-breeding anurans, with little attention paid to stream-associated salamanders. We sampled three frog and three salamander species in the Chesapeake and Ohio Canal National Historic Park, Maryland, by swabbing animals for PCR analysis to detect DNA of B. dendrobatidis. Using PCR, we detected B. dendrobatidis DNA in both stream and wetland amphibians, and report here the first occurrence of the pathogen in two species of stream-associated salamanders. Future research should focus on mechanisms within habitats that may affect persistence and dissemination of B. dendrobatidis among stream-associated salamanders.

  11. Successful treatment of Batrachochytrium salamandrivorans infections in salamanders requires synergy between voriconazole, polymyxin E and temperature.

    Science.gov (United States)

    Blooi, M; Pasmans, F; Rouffaer, L; Haesebrouck, F; Vercammen, F; Martel, A

    2015-01-01

    Chytridiomycosis caused by the chytrid fungus Batrachochytrium salamandrivorans (Bsal) poses a serious threat to urodelan diversity worldwide. Antimycotic treatment of this disease using protocols developed for the related fungus Batrachochytrium dendrobatidis (Bd), results in therapeutic failure. Here, we reveal that this therapeutic failure is partly due to different minimum inhibitory concentrations (MICs) of antimycotics against Bsal and Bd. In vitro growth inhibition of Bsal occurs after exposure to voriconazole, polymyxin E, itraconazole and terbinafine but not to florfenicol. Synergistic effects between polymyxin E and voriconazole or itraconazole significantly decreased the combined MICs necessary to inhibit Bsal growth. Topical treatment of infected fire salamanders (Salamandra salamandra), with voriconazole or itraconazole alone (12.5 μg/ml and 0.6 μg/ml respectively) or in combination with polymyxin E (2000 IU/ml) at an ambient temperature of 15 °C during 10 days decreased fungal loads but did not clear Bsal infections. However, topical treatment of Bsal infected animals with a combination of polymyxin E (2000 IU/ml) and voriconazole (12.5 μg/ml) at an ambient temperature of 20 °C resulted in clearance of Bsal infections. This treatment protocol was validated in 12 fire salamanders infected with Bsal during a field outbreak and resulted in clearance of infection in all animals. PMID:26123899

  12. Co-Infection by Chytrid Fungus and Ranaviruses in Wild and Harvested Frogs in the Tropical Andes.

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    Robin W Warne

    Full Text Available While global amphibian declines are associated with the spread of Batrachochytrium dendrobatidis (Bd, undetected concurrent co-infection by other pathogens may be little recognized threats to amphibians. Emerging viruses in the genus Ranavirus (Rv also cause die-offs of amphibians and other ectotherms, but the extent of their distribution globally, or how co-infections with Bd impact amphibians are poorly understood. We provide the first report of Bd and Rv co-infection in South America, and the first report of Rv infections in the amphibian biodiversity hotspot of the Peruvian Andes, where Bd is associated with extinctions. Using these data, we tested the hypothesis that Bd or Rv parasites facilitate co-infection, as assessed by parasite abundance or infection intensity within individual adult frogs. Co-infection occurred in 30% of stream-dwelling frogs; 65% were infected by Bd and 40% by Rv. Among terrestrial, direct-developing Pristimantis frogs 40% were infected by Bd, 35% by Rv, and 20% co-infected. In Telmatobius frogs harvested for the live-trade 49% were co-infected, 92% were infected by Bd, and 53% by Rv. Median Bd and Rv loads were similar in both wild (Bd = 101.2 Ze, Rv = 102.3 viral copies and harvested frogs (Bd = 103.1 Ze, Rv = 102.7 viral copies. While neither parasite abundance nor infection intensity were associated with co-infection patterns in adults, these data did not include the most susceptible larval and metamorphic life stages. These findings suggest Rv distribution is global and that co-infection among these parasites may be common. These results raise conservation concerns, but greater testing is necessary to determine if parasite interactions increase amphibian vulnerability to secondary infections across differing life stages, and constitute a previously undetected threat to declining populations. Greater surveillance of parasite interactions may increase our capacity to contain and mitigate the impacts of these and

  13. Co-Infection by Chytrid Fungus and Ranaviruses in Wild and Harvested Frogs in the Tropical Andes.

    Science.gov (United States)

    Warne, Robin W; LaBumbard, Brandon; LaGrange, Seth; Vredenburg, Vance T; Catenazzi, Alessandro

    2016-01-01

    While global amphibian declines are associated with the spread of Batrachochytrium dendrobatidis (Bd), undetected concurrent co-infection by other pathogens may be little recognized threats to amphibians. Emerging viruses in the genus Ranavirus (Rv) also cause die-offs of amphibians and other ectotherms, but the extent of their distribution globally, or how co-infections with Bd impact amphibians are poorly understood. We provide the first report of Bd and Rv co-infection in South America, and the first report of Rv infections in the amphibian biodiversity hotspot of the Peruvian Andes, where Bd is associated with extinctions. Using these data, we tested the hypothesis that Bd or Rv parasites facilitate co-infection, as assessed by parasite abundance or infection intensity within individual adult frogs. Co-infection occurred in 30% of stream-dwelling frogs; 65% were infected by Bd and 40% by Rv. Among terrestrial, direct-developing Pristimantis frogs 40% were infected by Bd, 35% by Rv, and 20% co-infected. In Telmatobius frogs harvested for the live-trade 49% were co-infected, 92% were infected by Bd, and 53% by Rv. Median Bd and Rv loads were similar in both wild (Bd = 101.2 Ze, Rv = 102.3 viral copies) and harvested frogs (Bd = 103.1 Ze, Rv = 102.7 viral copies). While neither parasite abundance nor infection intensity were associated with co-infection patterns in adults, these data did not include the most susceptible larval and metamorphic life stages. These findings suggest Rv distribution is global and that co-infection among these parasites may be common. These results raise conservation concerns, but greater testing is necessary to determine if parasite interactions increase amphibian vulnerability to secondary infections across differing life stages, and constitute a previously undetected threat to declining populations. Greater surveillance of parasite interactions may increase our capacity to contain and mitigate the impacts of these and other wildlife

  14. No detection of chytrid in first systematic screening of Bombina variegata pachypus (Anura: Bombinatoridae in Liguria, northern Italy

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    Stefano Canessa

    2013-07-01

    Full Text Available The Apennine Yellow-bellied toad Bombina variegata pachypus, a small anuran endemic to peninsular Italy, has been declining throughout its range over the last 30 years. Although mortality by chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis, was first reported for the species in 2004, its role in the decline has not yet been assessed. Between 2011 and 2012 we sampled eight populations of B. v. pachypus in Liguria, northern Italy, swabbing 86 and 143 individuals respectively, corresponding to between 24 and 80% of the estimated individuals within each population. We did not detect chytrid in any the samples collected. For the three largest populations in the region, we can rule out infections of prevalence greater than 10% with at least 98% confidence. Research at a larger scale is urgently needed to clarify the role of B. dendrobatidis in the decline of this and other amphibians in Italy.

  15. The lethal fungus Batrachochytrium dendrobatidis is present in lowland tropical forests of far eastern Panamá.

    Science.gov (United States)

    Rebollar, Eria A; Hughey, Myra C; Harris, Reid N; Domangue, Rickie J; Medina, Daniel; Ibáñez, Roberto; Belden, Lisa K

    2014-01-01

    The fungal disease chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), is one of the main causes of amphibian population declines and extinctions all over the world. In the Neotropics, this fungal disease has caused catastrophic declines in the highlands as it has spread throughout Central America down to Panamá. In this study, we determined the prevalence and intensity of Bd infection in three species of frogs in one highland and four lowland tropical forests, including two lowland regions in eastern Panamá in which the pathogen had not been detected previously. Bd was present in all the sites sampled with a prevalence ranging from 15-34%, similar to other Neotropical lowland sites. The intensity of Bd infection on individual frogs was low, ranging from average values of 0.11-24 zoospore equivalents per site. Our work indicates that Bd is present in anuran communities in lowland Panamá, including the Darién province, and that the intensity of the infection may vary among species from different habitats and with different life histories. The population-level consequences of Bd infection in amphibian communities from the lowlands remain to be determined. Detailed studies of amphibian species from the lowlands will be essential to determine the reason why these species are persisting despite the presence of the pathogen. PMID:24740162

  16. Presence and significance of chytrid fungus Batrachochytrium dendrobatidis and other amphibian pathogens at warm-water fish hatcheries in southeastern North America

    Science.gov (United States)

    Green, D. Earl; Dodd, C. Kenneth, Jr.

    2007-01-01

    Amphibian populations and species are declining or disappearing from many regions throughout the world (Stuart et al. 2004). No single cause has been demonstrated, although a number of emerging infectious diseases have been suggested as primary etiologic agents (Berger et al. 1998; Daszak et al. 2003; Lips et al. 2006). Several factors, including climate change, parasite infestation or compromised immune systems may interact locally or regionally to threaten species and populations (Carey and Bryant 1995; Parris and Beaudoin 2004; Pounds et al. 2006). Still, the disease model of amphibian decline may not be universally applicable (Daszak et al. 2005; McCallum 2005).

  17. Thermoregulatory behaviour affects prevalence of chytrid fungal infection in a wild population of Panamanian golden frogs.

    Science.gov (United States)

    Richards-Zawacki, Corinne L

    2010-02-22

    Predicting how climate change will affect disease dynamics requires an understanding of how the environment affects host-pathogen interactions. For amphibians, global declines and extinctions have been linked to a pathogenic chytrid fungus, Batrachochytrium dendrobatidis. Using a combination of body temperature measurements and disease assays conducted before and after the arrival of B. dendrobatidis, this study tested the hypothesis that body temperature affects the prevalence of infection in a wild population of Panamanian golden frogs (Atelopus zeteki). The timing of first detection of the fungus was consistent with that of a wave of epidemic infections spreading south and eastward through Central America. During the epidemic, many golden frogs modified their thermoregulatory behaviour, raising body temperatures above their normal set point. Odds of infection decreased with increasing body temperature, demonstrating that even slight environmental or behavioural changes have the potential to affect an individual's vulnerability to infection. The thermal dependency of the relationship between B. dendrobatidis and its amphibian hosts demonstrates how the progression of an epidemic can be influenced by complex interactions between host and pathogen phenotypes and the environments in which they are found. PMID:19864287

  18. Joint effects of habitat, zooplankton, host stage structure and diversity on amphibian chytrid.

    Science.gov (United States)

    Hite, Jessica L; Bosch, Jaime; Fernández-Beaskoetxea, Saioa; Medina, Daniel; Hall, Spencer R

    2016-07-27

    Why does the severity of parasite infection differ dramatically across habitats? This question remains challenging to answer because multiple correlated pathways drive disease. Here, we examined habitat-disease links through direct effects on parasites and indirect effects on parasite predators (zooplankton), host diversity and key life stages of hosts. We used a case study of amphibian hosts and the chytrid fungus, Batrachochytrium dendrobatidis, in a set of permanent and ephemeral alpine ponds. A field experiment showed that ultraviolet radiation (UVR) killed the free-living infectious stage of the parasite. Yet, permanent ponds with more UVR exposure had higher infection prevalence. Two habitat-related indirect effects worked together to counteract parasite losses from UVR: (i) UVR reduced the density of parasite predators and (ii) permanent sites fostered multi-season host larvae that fuelled parasite production. Host diversity was unlinked to hydroperiod or UVR but counteracted parasite gains; sites with higher diversity of host species had lower prevalence of infection. Thus, while habitat structure explained considerable variation in infection prevalence through two indirect pathways, it could not account for everything. This study demonstrates the importance of creating mechanistic, food web-based links between multiple habitat dimensions and disease. PMID:27466456

  19. Evidence of a salt refuge: chytrid infection loads are suppressed in hosts exposed to salt.

    Science.gov (United States)

    Stockwell, M P; Clulow, J; Mahony, M J

    2015-03-01

    With the incidence of emerging infectious diseases on the rise, it is becoming increasingly important to identify refuge areas that protect hosts from pathogens and therefore prevent population declines. For the chytrid fungus Batrachochytrium dendrobatidis, temperature and humidity refuge areas for amphibian hosts exist but are difficult to manipulate. Other environmental features that may affect the outcome of infection include water quality, drying regimes, abundance of alternate hosts and isolation from other hosts. We identified relationships between water bodies with these features and infection levels in the free-living hosts inhabiting them. Where significant relationships were identified, we used a series of controlled experiments to test for causation. Infection loads were negatively correlated with the salt concentration of the aquatic habitat and the degree of water level fluctuation and positively correlated with fish abundance. However, only the relationship with salt was confirmed experimentally. Free-living hosts inhabiting water bodies with mean salinities of up to 3.5 ppt had lower infection loads than those exposed to less salt. The experiment confirmed that exposure to sodium chloride concentrations >2 ppt significantly reduced host infection loads compared to no exposure (0 ppt). These results suggest that the exposure of amphibians to salt concentrations found naturally in lentic habitats may be responsible for the persistence of some susceptible species in the presence of B. dendrobatidis. By manipulating the salinity of water bodies, it may be possible to create refuges for declining amphibians, thus allowing them to be reintroduced to their former ranges. PMID:25416999

  20. Dead or alive? Viability of chytrid zoospores shed from live amphibian hosts.

    Science.gov (United States)

    Maguire, Chelsea; DiRenzo, Graziella V; Tunstall, Tate S; Muletz, Carly R; Zamudio, Kelly R; Lips, Karen R

    2016-05-26

    Pathogens vary in virulence and rates of transmission because of many differences in the host, the pathogen, and their environment. The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), affects amphibian hosts differently, causing extinction and population declines in some species but having limited effects on others. Phenotypic differences in zoospore production rates among Bd lineages likely contribute to some of the variation observed among host responses, although no studies have quantified the viability of zoospores shed from live animals. We compared host survivorship, infection intensity, shedding rates, and zoospore viability between 2 species of endangered tropical frogs, Hylomantis lemur and Atelopus zeteki, when exposed to a highly virulent lineage of Bd (JEL 423). We applied a dye to zoospores 30 to 60 min following animal soaks, to estimate shedding rate and proportion of live zoospores shed by different species. The average infection intensity for A. zeteki was nearly 17 times higher (31,455 ± 10,103 zoospore genomic equivalents [ZGEs]) than that of H. lemur (1832 ± 1086 ZGEs), and A. zeteki died earlier than H. lemur. The proportion of viable zoospores was ~80% in both species throughout the experiment, although A. zeteki produced many more zoospores, suggesting it may play a disproportionate role in spreading disease in communities where it occurs, because the large number of viable zoospores they produce might increase infection in other species where they are reintroduced. PMID:27225201

  1. Batrachochytrium dendrobatidis in natural and farmed Louisiana crayfish populations: prevalence and implications.

    Science.gov (United States)

    Brannelly, Laura A; McMahon, Taegan A; Hinton, Mitchell; Lenger, Daniel; Richards-Zawacki, Corinne L

    2015-01-15

    The pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd) has been linked to global declines and extinctions of amphibians, making it one of the most devastating wildlife pathogens known. Understanding the factors that affect disease dynamics in this system is critical for mitigating infection and protecting threatened species. Crayfish are hosts of this pathogen and can transmit Bd to amphibians. Because they co-occur with susceptible amphibian communities, crayfish may be important alternative hosts for Bd. Understanding the prevalence and seasonal dynamics of crayfish infections is of agricultural and ecological interest in areas where crayfish are farmed and traded for human consumption. We conducted a survey of Bd in farmed and natural crayfish (Procambarus spp.) populations in Louisiana, USA. We found that Bd prevalence and infection intensity was low in both farmed and native populations and that prevalence varied seasonally in wild Louisiana crayfish. This seasonal pattern mirrors that seen in local amphibians. As crayfish are an important globally traded freshwater taxon, even with low prevalence, they could be an important vector in the spread of Bd. PMID:25590773

  2. Prevalence of Batrachochytrium dendrobatidis in Eastern Hellbender (Cryptobranchus alleganiensis) Populations in West Virginia, USA.

    Science.gov (United States)

    Seeley, Kathryn E; D'Angelo, Melanie; Gowins, Caitlin; Greathouse, Joe

    2016-04-28

    The eastern hellbender (Cryptobranchus alleganiensis alleganiensis) is a North American salamander species in decline throughout its range. Efforts to identify the causes of decline have included surveillance for the chytrid fungus Batrachochytrium dendrobatidis (Bd), which has been associated with global amphibian population losses. We evaluated the prevalence of Bd in 42 hellbenders at four sites in West Virginia, US, from June to September 2013, using standard swab protocols and real-time PCR. Overall prevalence of Bd was 52% (22/42; 37.7-66.6%; 95% confidence interval). Prevalence was highest in individuals with body weight ≥695 g (χ(2)=7.2487, df=1, P=0.007), and was higher in montane sampling sites than lowland sites (t=-2.4599, df=44, P=0.02). While increased prevalence in montane sampling sites was expected, increased prevalence in larger hellbenders was unexpected and hypothesized to be associated with greater surface area for infection or prolonged periods of exposure in older, larger hellbenders. Wild hellbenders have not been reported to display clinical disease associated with Bd; however, prevalence in the population is important information for evaluating reservoir status and risk to other species, and as a baseline for investigation in the face of an outbreak of clinical disease. PMID:27124331

  3. Quantitative Proteomics of an Amphibian Pathogen, Batrachochytrium dendrobatidis, following Exposure to Thyroid Hormone.

    Directory of Open Access Journals (Sweden)

    Jose Thekkiniath

    Full Text Available Batrachochytrium dendrobatidis (Bd, a chytrid fungus, has increasingly been implicated as a major factor in the worldwide decline of amphibian populations. The fungus causes chytridiomycosis in susceptible species leading to massive die-offs of adult amphibians. Although Bd infects the keratinized mouthparts of tadpoles and negatively affects foraging behavior, these infections are non-lethal. An important morphogen controlling amphibian metamorphosis is thyroid hormone (T3. Tadpoles may be infected with Bd and the fungus may be exposed to T3 during metamorphosis. We hypothesize that exposure of Bd to T3 may induce the expression of factors associated with host colonization and pathogenicity. We utilized a proteomics approach to better understand the dynamics of the Bd-T3 interaction. Using liquid chromatography-mass spectrometry (LC-MS, we generated a data set of a large number of cytoplasmic and membrane proteins following exposure of Bd to T3. From these data, we identified a total of 263 proteins whose expression was significantly changed following T3 exposure. We provide evidence for expression of an array of proteins that may play key roles in both genomic and non-genomic actions of T3 in Bd. Additionally, our proteomics study shows an increase in several proteins including proteases and a class of uncommon crinkler and crinkler-like effector proteins suggesting their importance in Bd pathogenicity as well as those involved in metabolism and energy transfer, protein fate, transport and stress responses. This approach provides insights into the mechanistic basis of the Bd-amphibian interaction following T3 exposure.

  4. Field and laboratory studies of the susceptibility of the green treefrog (Hyla cinerea to Batrachochytrium dendrobatidis infection.

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    Laura A Brannelly

    Full Text Available Amphibians worldwide are experiencing devastating declines, some of which are due to the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd. Populations in the southeastern United States, however, have not been noticeably affected by the pathogen. The green treefrog (Hyla cinerea is abundant and widespread in the southeastern United States, but has not been documented to harbor Bd infection. This study examined the susceptibility of H. cinerea to two strains of Bd in the lab and the prevalence of infection in wild populations of this species in southeastern Louisiana. Although we were able to infect H. cinerea with Bd in the lab, we did not observe any clinical signs of chytridiomycosis. Furthermore, infection by Bd does not appear to negatively affect body condition or growth rate of post-metamorphic individuals. We found no evidence of infection in surveys of wild H. cinerea. Our results suggest that H. cinerea is not susceptible to chytridiomycosis post-metamorphosis and probably is not an important carrier of the fungal pathogen Bd in the southeastern United States, although susceptibility at the larval stage remains unknown.

  5. Bd on the beach: high prevalence of Batrachochytrium dendrobatidis in the lowland forests of Gorgona Island (Colombia, South America).

    Science.gov (United States)

    Flechas, Sandra Victoria; Sarmiento, Carolina; Amézquita, Adolfo

    2012-09-01

    The amphibian chytrid fungus, Batrachochytrium dendrobatidis, Bd, has been implicated in the decimation and extinction of many amphibian populations worldwide, especially at mid and high elevations. Recent studies have demonstrated the presence of the pathogen in the lowlands from Australia and Central America. We extend here its elevational range by demonstrating its presence at the sea level, in the lowland forests of Gorgona Island, off the Pacific coast of Colombia. We conducted two field surveys, separated by four years, and diagnosed Bd by performing polymerase chain reactions on swab samples from the skin of five amphibian species. All species, including the Critically Endangered Atelopus elegans, tested positive for the pathogen, with prevalences between 3.9 % in A. elegans (in 2010) and 52 % in Pristimantis achatinus. Clinical signs of chytridiomycosis were not detected in any species. To our knowledge, this is the first report of B. dendrobatidis in tropical lowlands at sea level, where temperatures may exceed optimal growth temperatures of this pathogen. This finding highlights the need to understand the mechanisms allowing the interaction between frogs and pathogen in lowland ecosystems. PMID:22669408

  6. A fungal pathogen of amphibians, Batrachochytrium dendrobatidis, attenuates in pathogenicity with in vitro passages.

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    Penny F Langhammer

    Full Text Available Laboratory investigations into the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd, have accelerated recently, given the pathogen's role in causing the global decline and extinction of amphibians. Studies in which host animals were exposed to Bd have largely assumed that lab-maintained pathogen cultures retained the infective and pathogenic properties of wild isolates. Attenuated pathogenicity is common in artificially maintained cultures of other pathogenic fungi, but to date, it is unknown whether, and to what degree, Bd might change in culture. We compared zoospore production over time in two samples of a single Bd isolate having different passage histories: one maintained in artificial media for more than six years (JEL427-P39, and one recently thawed from cryopreserved stock (JEL427-P9. In a common garden experiment, we then exposed two different amphibian species, Eleutherodactylus coqui and Atelopus zeteki, to both cultures to test whether Bd attenuates in pathogenicity with in vitro passages. The culture with the shorter passage history, JEL427-P9, had significantly greater zoospore densities over time compared to JEL427-P39. This difference in zoospore production was associated with a difference in pathogenicity for a susceptible amphibian species, indicating that fecundity may be an important virulence factor for Bd. In the 130-day experiment, Atelopus zeteki frogs exposed to the JEL427-P9 culture experienced higher average infection intensity and 100% mortality, compared with 60% mortality for frogs exposed to JEL427-P39. This effect was not observed with Eleutherodactylus coqui, which was able to clear infection. We hypothesize that the differences in phenotypic performance observed with Atelopus zeteki are rooted in changes of the Bd genome. Future investigations enabled by this study will focus on the underlying mechanisms of Bd pathogenicity.

  7. A fungal pathogen of amphibians, Batrachochytrium dendrobatidis, attenuates in pathogenicity with in vitro passages.

    Science.gov (United States)

    Langhammer, Penny F; Lips, Karen R; Burrowes, Patricia A; Tunstall, Tate; Palmer, Crystal M; Collins, James P

    2013-01-01

    Laboratory investigations into the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), have accelerated recently, given the pathogen's role in causing the global decline and extinction of amphibians. Studies in which host animals were exposed to Bd have largely assumed that lab-maintained pathogen cultures retained the infective and pathogenic properties of wild isolates. Attenuated pathogenicity is common in artificially maintained cultures of other pathogenic fungi, but to date, it is unknown whether, and to what degree, Bd might change in culture. We compared zoospore production over time in two samples of a single Bd isolate having different passage histories: one maintained in artificial media for more than six years (JEL427-P39), and one recently thawed from cryopreserved stock (JEL427-P9). In a common garden experiment, we then exposed two different amphibian species, Eleutherodactylus coqui and Atelopus zeteki, to both cultures to test whether Bd attenuates in pathogenicity with in vitro passages. The culture with the shorter passage history, JEL427-P9, had significantly greater zoospore densities over time compared to JEL427-P39. This difference in zoospore production was associated with a difference in pathogenicity for a susceptible amphibian species, indicating that fecundity may be an important virulence factor for Bd. In the 130-day experiment, Atelopus zeteki frogs exposed to the JEL427-P9 culture experienced higher average infection intensity and 100% mortality, compared with 60% mortality for frogs exposed to JEL427-P39. This effect was not observed with Eleutherodactylus coqui, which was able to clear infection. We hypothesize that the differences in phenotypic performance observed with Atelopus zeteki are rooted in changes of the Bd genome. Future investigations enabled by this study will focus on the underlying mechanisms of Bd pathogenicity. PMID:24130895

  8. Assessing host extinction risk following exposure to Batrachochytrium dendrobatidis

    OpenAIRE

    Louca, Stilianos; Lampo, Margarita; Doebeli, Michael

    2014-01-01

    Wildlife diseases are increasingly recognized as a major threat to biodiversity. Chytridiomycosis is an emerging infectious disease of amphibians caused by the fungus Batrachochytrium dendrobatidis (Bd). Using a mathematical model and simulations, we study its effects on a generic riparian host population with a tadpole and adult life stage. An analytical expression for the basic reproduction quotient, Qo, of the pathogen is derived. By sampling the entire relevant parameter space, we perform...

  9. Early 1900s Detection of Batrachochytrium dendrobatidis in Korean Amphibians

    OpenAIRE

    Fong, Jonathan J.; Cheng, Tina L.; Bataille, Arnaud; Allan P Pessier; Waldman, Bruce; Vance T Vredenburg

    2015-01-01

    The pathogenic fungus Batrachochytrium dendrobatidis (Bd) is a major conservation concern because of its role in decimating amphibian populations worldwide. We used quantitative PCR to screen 244 museum specimens from the Korean Peninsula, collected between 1911 and 2004, for the presence of Bd to gain insight into its history in Asia. Three specimens of Rugosa emeljanovi (previously Rana or Glandirana rugosa), collected in 1911 from Wonsan, North Korea, tested positive for Bd. Histology of t...

  10. Variation in the Presence of Anti-Batrachochytrium dendrobatidis Bacteria of Amphibians Across Life Stages and Elevations in Ecuador.

    Science.gov (United States)

    Bresciano, J C; Salvador, C A; Paz-Y-Miño, C; Parody-Merino, A M; Bosch, J; Woodhams, D C

    2015-06-01

    Amphibian populations are decreasing worldwide due to a variety of factors. In South America, the chytrid fungus Batrachochytrium dendrobatidis (Bd) is linked to many population declines. The pathogenic effect of Bd on amphibians can be inhibited by specific bacteria present on host skin. This symbiotic association allows some amphibians to resist the development of the disease chytridiomycosis. Here, we aimed (1) to determine for the first time if specific anti-Bd bacteria are present on amphibians in the Andes of Ecuador, (2) to monitor anti-Bd bacteria across developmental stages in a focal amphibian, the Andean marsupial tree frog, Gastrotheca riobambae, that deposits larvae in aquatic habitats, and (3) to compare the Bd presence associated with host assemblages including 10 species at sites ranging in biogeography from Amazonian rainforest (450 masl) to Andes montane rainforest (3200 masl). We sampled and identified skin-associated bacteria of frogs in the field using swabs and a novel methodology of aerobic counting plates, and a combination of morphological, biochemical, and molecular identification techniques. The following anti-Bd bacteria were identified and found to be shared among several hosts at high-elevation sites where Bd was present at a prevalence of 32.5%: Janthinobacterium lividum, Pseudomonas fluorescens, and Serratia sp. Bd were detected in Gastrotheca spp. and not detected in the lowlands (sites below 1000 masl). In G. riobambae, recognized Bd-resistant bacteria start to be present at the metamorphic stage. Overall bacterial abundance was significantly higher post-metamorphosis and on species sampled at lower elevations. Further metagenomic studies are needed to evaluate the roles of host identity, life-history stage, and biogeography of the microbiota and their function in disease resistance. PMID:25669915

  11. Tolerance of fungal infection in European water frogs exposed to Batrachochytrium dendrobatidis after experimental reduction of innate immune defenses

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    Woodhams Douglas C

    2012-10-01

    Full Text Available Abstract Background While emerging diseases are affecting many populations of amphibians, some populations are resistant. Determining the relative contributions of factors influencing disease resistance is critical for effective conservation management. Innate immune defenses in amphibian skin are vital host factors against a number of emerging pathogens such as ranaviruses and the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd. Adult water frogs from Switzerland (Pelophylax esculentus and P. lessonae collected in the field with their natural microbiota intact were exposed to Bd after experimental reduction of microbiota, skin peptides, both, or neither to determine the relative contributions of these defenses. Results Naturally-acquired Bd infections were detected in 10/51 P. lessonae and 4/19 P. esculentus, but no disease outbreaks or population declines have been detected at this site. Thus, this population was immunologically primed, and disease resistant. No mortality occurred during the 64 day experiment. Forty percent of initially uninfected frogs became sub-clinically infected upon experimental exposure to Bd. Reduction of both skin peptide and microbiota immune defenses caused frogs to gain less mass when exposed to Bd than frogs in other treatments. Microbiota-reduced frogs increased peptide production upon Bd infection. Ranavirus was undetectable in all but two frogs that appeared healthy in the field, but died within a week under laboratory conditions. Virus was detectable in both toe-clips and internal organs. Conclusion Intact skin microbiota reduced immune activation and can minimize subclinical costs of infection. Tolerance of Bd or ranavirus infection may differ with ecological conditions.

  12. Projecting the Global Distribution of the Emerging Amphibian Fungal Pathogen, Batrachochytrium dendrobatidis, Based on IPCC Climate Futures

    Science.gov (United States)

    Olson, Deanna H.; Blaustein, Andrew R.

    2016-01-01

    Projected changes in climate conditions are emerging as significant risk factors to numerous species, affecting habitat conditions and community interactions. Projections suggest species range shifts in response to climate change modifying environmental suitability and is supported by observational evidence. Both pathogens and their hosts can shift ranges with climate change. We consider how climate change may influence the distribution of the emerging infectious amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), a pathogen associated with worldwide amphibian population losses. Using an expanded global Bd database and a novel modeling approach, we examined a broad set of climate metrics to model the Bd-climate niche globally and regionally, then project how climate change may influence Bd distributions. Previous research showed that Bd distribution is dependent on climatic variables, in particular temperature. We trained a machine-learning model (random forest) with the most comprehensive global compilation of Bd sampling records (~5,000 site-level records, mid-2014 summary), including 13 climatic variables. We projected future Bd environmental suitability under IPCC scenarios. The learning model was trained with combined worldwide data (non-region specific) and also separately per region (region-specific). One goal of our study was to estimate of how Bd spatial risks may change under climate change based on the best available data. Our models supported differences in Bd-climate relationships among geographic regions. We projected that Bd ranges will shift into higher latitudes and altitudes due to increased environmental suitability in those regions under predicted climate change. Specifically, our model showed a broad expansion of areas environmentally suitable for establishment of Bd on amphibian hosts in the temperate zones of the Northern Hemisphere. Our projections are useful for the development of monitoring designs in these areas, especially for

  13. The Search for Violacein-Producing Microbes to Combat Batrachochytrium dendrobatidis: A Collaborative Research Project between Secondary School and College Research Students

    OpenAIRE

    Larra Agate; Deborah Beam; Colleen Bucci; Yegor Dukashin; Raneem Jo'beh; Kelsey O'Brien; Jude, Brooke A.

    2015-01-01

    In this citizen science–aided, college laboratory–based microbiology research project, secondary school students collaborate with college research students on an investigation centered around bacterial species in the local watershed. This study specifically investigated the prevalence of violacein-producing bacterial isolates, as violacein has been demonstrated as a potential bioremediation treatment for outbreaks of the worldwide invasive chytrid, Batrachochytrium dendrobatidis (Bd). The imp...

  14. Fungal infection intensity and zoospore output of Atelopus zeteki, a potential acute chytrid supershedder.

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    Graziella V Direnzo

    Full Text Available Amphibians vary in their response to infection by the amphibian-killing chytrid fungus, Batrachochytrium dendrobatidis (Bd. Highly susceptible species are the first to decline and/or disappear once Bd arrives at a site. These competent hosts likely facilitate Bd proliferation because of ineffective innate and/or acquired immune defenses. We show that Atelopus zeteki, a highly susceptible species that has undergone substantial population declines throughout its range, rapidly and exponentially increases skin Bd infection intensity, achieving intensities that are several orders of magnitude greater than most other species reported. We experimentally infected individuals that were never exposed to Bd (n = 5 or previously exposed to an attenuated Bd strain (JEL427-P39; n = 3. Within seven days post-inoculation, the average Bd infection intensity was 18,213 zoospores (SE: 9,010; range: 0 to 66,928. Both average Bd infection intensity and zoospore output (i.e., the number of zoospores released per minute by an infected individual increased exponentially until time of death (t50 = 7.018, p<0.001, t46 = 3.164, p = 0.001, respectively. Mean Bd infection intensity and zoospore output at death were 4,334,422 zoospores (SE: 1,236,431 and 23.55 zoospores per minute (SE: 22.78, respectively, with as many as 9,584,158 zoospores on a single individual. The daily percent increases in Bd infection intensity and zoospore output were 35.4% (SE: 0.05 and 13.1% (SE: 0.04, respectively. We also found that Bd infection intensity and zoospore output were positively correlated (t43 = 3.926, p<0.001. All animals died between 22 and 33 days post-inoculation (mean: 28.88; SE: 1.58. Prior Bd infection had no effect on survival, Bd infection intensity, or zoospore output. We conclude that A. zeteki, a highly susceptible amphibian species, may be an acute supershedder. Our results can inform epidemiological models to estimate Bd outbreak probability, especially as they relate

  15. Fungal infection intensity and zoospore output of Atelopus zeteki, a potential acute chytrid supershedder.

    Science.gov (United States)

    Direnzo, Graziella V; Langhammer, Penny F; Zamudio, Kelly R; Lips, Karen R

    2014-01-01

    Amphibians vary in their response to infection by the amphibian-killing chytrid fungus, Batrachochytrium dendrobatidis (Bd). Highly susceptible species are the first to decline and/or disappear once Bd arrives at a site. These competent hosts likely facilitate Bd proliferation because of ineffective innate and/or acquired immune defenses. We show that Atelopus zeteki, a highly susceptible species that has undergone substantial population declines throughout its range, rapidly and exponentially increases skin Bd infection intensity, achieving intensities that are several orders of magnitude greater than most other species reported. We experimentally infected individuals that were never exposed to Bd (n = 5) or previously exposed to an attenuated Bd strain (JEL427-P39; n = 3). Within seven days post-inoculation, the average Bd infection intensity was 18,213 zoospores (SE: 9,010; range: 0 to 66,928). Both average Bd infection intensity and zoospore output (i.e., the number of zoospores released per minute by an infected individual) increased exponentially until time of death (t50 = 7.018, p<0.001, t46 = 3.164, p = 0.001, respectively). Mean Bd infection intensity and zoospore output at death were 4,334,422 zoospores (SE: 1,236,431) and 23.55 zoospores per minute (SE: 22.78), respectively, with as many as 9,584,158 zoospores on a single individual. The daily percent increases in Bd infection intensity and zoospore output were 35.4% (SE: 0.05) and 13.1% (SE: 0.04), respectively. We also found that Bd infection intensity and zoospore output were positively correlated (t43 = 3.926, p<0.001). All animals died between 22 and 33 days post-inoculation (mean: 28.88; SE: 1.58). Prior Bd infection had no effect on survival, Bd infection intensity, or zoospore output. We conclude that A. zeteki, a highly susceptible amphibian species, may be an acute supershedder. Our results can inform epidemiological models to estimate Bd outbreak probability, especially as they relate to

  16. Trophic dynamics in an aquatic community: interactions among primary producers, grazers, and a pathogenic fungus.

    Science.gov (United States)

    Buck, Julia C; Scholz, Katharina I; Rohr, Jason R; Blaustein, Andrew R

    2015-05-01

    Free-living stages of parasites are consumed by a variety of predators, which might have important consequences for predators, parasites, and hosts. For example, zooplankton prey on the infectious stage of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), a pathogen responsible for amphibian population declines and extinctions worldwide. Predation on parasites is predicted to influence community structure and function, and affect disease risk, but relatively few studies have explored its consequences empirically. We investigated interactions among Rana cascadae tadpoles, zooplankton, and Bd in a fully factorial experiment in outdoor mesocosms. We measured growth, development, survival, and infection of amphibians and took weekly measurements of the abundance of zooplankton, phytoplankton (suspended algae), and periphyton (attached algae). We hypothesized that zooplankton might have positive indirect effects on tadpoles by consuming Bd zoospores and by consuming phytoplankton, thus reducing the shading of a major tadpole resource, periphyton. We also hypothesized that zooplankton would have negative effects on tadpoles, mediated by competition for algal resources. Mixed-effects models, repeated-measures ANOVAs, and a structural equation model revealed that zooplankton significantly reduced phytoplankton but had no detectable effects on Bd or periphyton. Hence, the indirect positive effects of zooplankton on tadpoles were negligible when compared to the indirect negative effect mediated by competition for phytoplankton. We conclude that examination of host-pathogen dynamics within a community context may be necessary to elucidate complex community dynamics. PMID:25432573

  17. Unlikely remedy: fungicide clears infection from pathogenic fungus in larval southern leopard frogs (Lithobates sphenocephalus.

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    Shane M Hanlon

    Full Text Available Amphibians are often exposed to a wide variety of perturbations. Two of these, pesticides and pathogens, are linked to declines in both amphibian health and population viability. Many studies have examined the separate effects of such perturbations; however, few have examined the effects of simultaneous exposure of both to amphibians. In this study, we exposed larval southern leopard frog tadpoles (Lithobates sphenocephalus to the chytrid fungus Batrachochytrium dendrobatidis and the fungicide thiophanate-methyl (TM at 0.6 mg/L under laboratory conditions. The experiment was continued until all larvae completed metamorphosis or died. Overall, TM facilitated increases in tadpole mass and length. Additionally, individuals exposed to both TM and Bd were heavier and larger, compared to all other treatments. TM also cleared Bd in infected larvae. We conclude that TM affects larval anurans to facilitate growth and development while clearing Bd infection. Our findings highlight the need for more research into multiple perturbations, specifically pesticides and disease, to further promote amphibian heath.

  18. Survival of Batrachochytrium dendrobatidis in Water: Quarantine and Disease Control Implications

    OpenAIRE

    Johnson, Megan L.; Speare, Richard

    2003-01-01

    Amphibian chytridiomycosis is an emerging infectious disease of amphibians thought to be moved between countries by trade in infected amphibians. The causative fungus, Batrachochytrium dendrobatidis, produces aquatic, motile zoospores; infections have been achieved in experiments by exposing amphibians to water containing zoospores. However, the ability of this fungus to survive in the environment in the absence of an amphibian host is unknown. We show that B. dendrobatidis will survive in ta...

  19. The emerging amphibian pathogen Batrachochytrium dendrobatidis globally infects introduced populations of the North American bullfrog, Rana catesbeiana

    OpenAIRE

    Trenton W J Garner; Perkins, Matthew W.; Govindarajulu, Purnima; Seglie, Daniele; Walker, Susan; Cunningham, Andrew A.; Fisher, Matthew C

    2006-01-01

    Batrachochytrium dendrobatidis is the chytridiomycete fungus which has been implicated in global amphibian declines and numerous species extinctions. Here, we show that introduced North American bullfrogs (Rana catesbeiana) consistently carry this emerging pathogenic fungus. We detected infections by this fungus on introduced bullfrogs from seven of eight countries using both PCR and microscopic techniques. Only native bullfrogs from eastern Canada and introduced bullfrogs from Japan showed n...

  20. Mycoloop: chytrids in aquatic food webs.

    Science.gov (United States)

    Kagami, Maiko; Miki, Takeshi; Takimoto, Gaku

    2014-01-01

    Parasites are ecologically significant in various ecosystems through their role in shaping food web structure, facilitating energy transfer, and controlling disease. Here in this review, we mainly focus on parasitic chytrids, the dominant parasites in aquatic ecosystems, and explain their roles in aquatic food webs, particularly as prey for zooplankton. Chytrids have a free-living zoosporic stage, during which they actively search for new hosts. Zoospores are excellent food for zooplankton in terms of size, shape, and nutritional quality. In the field, densities of chytrids can be high, ranging from 10(1) to 10(9) spores L(-1). When large inedible phytoplankton species are infected by chytrids, nutrients within host cells are transferred to zooplankton via the zoospores of parasitic chytrids. This new pathway, the "mycoloop," may play an important role in shaping aquatic ecosystems, by altering sinking fluxes or determining system stability. The grazing of zoospores by zooplankton may also suppress outbreaks of parasitic chytrids. A food web model demonstrated that the contribution of the mycoloop to zooplankton production increased with nutrient availability and was also dependent on the stability of the system. Further studies with advanced molecular tools are likely to discover greater chytrid diversity and evidence of additional mycoloops in lakes and oceans. PMID:24795703

  1. Mycoloop: chytrids in aquatic food webs

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    Maiko eKagami

    2014-04-01

    Full Text Available Parasites are ecologically significant in various ecosystems through their role in shaping food web structure, facilitating energy transfer, and controlling disease. Here in this review, we mainly focus on parasitic chytrids, the dominant parasites in aquatic ecosystems, and explain their roles in aquatic food webs, particularly as prey for zooplankton. Chytrids have a free-living zoosporic stage, during which they actively search for new hosts. Zoospores are excellent food for zooplankton in terms of size, shape, and nutritional quality. In the field, densities of chytrids can be high, ranging from 101-109 spores L-1. When large inedible phytoplankton species are infected by chytrids, nutrients within host cells are transferred to zooplankton via the zoospores of parasitic chytrids. This new pathway, the ‘mycoloop,’ may play an important role in shaping aquatic ecosystems, by altering sinking fluxes or determining system stability. The grazing of zoospores by zooplankton may also suppress outbreaks of parasitic chytrids. A food web model demonstrated that the contribution of the mycoloop to zooplankton production increased with nutrient availability and was also dependent on the stability of the system. Further studies with advanced molecular tools are likely to discover greater chytrid diversity and evidence of additional mycoloops in lakes and oceans.

  2. Unexpected Rarity of the Pathogen Batrachochytrium dendrobatidis in Appalachian Plethodon Salamanders: 1957–2011

    OpenAIRE

    Muletz, Carly; Nicholas M Caruso; Fleischer, Robert C; Roy W McDiarmid; Lips, Karen R.

    2014-01-01

    Widespread population declines in terrestrial Plethodon salamanders occurred by the 1980s throughout the Appalachian Mountains, the center of global salamander diversity, with no evident recovery. We tested the hypothesis that the historic introduction and spread of the pathogenic fungus Batrachochytrium dendrobatidis (Bd) into the eastern US was followed by Plethodon population declines. We expected to detect elevated prevalence of Bd prior to population declines as observed for Central Amer...

  3. Short-Term Exposure to Warm Microhabitats Could Explain Amphibian Persistence with Batrachochytrium dendrobatidis

    OpenAIRE

    Daskin, Joshua H.; Ross A. Alford; Puschendorf, Robert

    2011-01-01

    Environmental conditions can alter the outcomes of symbiotic interactions. Many amphibian species have declined due to chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), but many others persist despite high Bd infection prevalence. This indicates that Bd's virulence is lower, or it may even be a commensal, in some hosts. In the Australian Wet Tropics, chytridiomycosis extirpated Litoria nannotis from high-elevation rain forests in the early 1990 s. Although...

  4. The use of singleplex and nested PCR to detect Batrachochytrium dendrobatidis in free-living frogs

    OpenAIRE

    Selene Dall'Acqua Coutinho; Julieta Catarina Burke; Catia Dejuste de Paula; Miguel Trefaut Rodrigues; José Luiz Catão-Dias

    2015-01-01

    Many microorganisms are able to cause diseases in amphibians, and in the past few years one of the most reported has been Batrachochytrium dendrobatidis. This fungus was first reported in Brazil in 2005; following this, other reports were made in specimens deposited in museum collections, captive and free-living frogs. The aim of this study was to compare singleplex and nested-PCR techniques to detect B. dendrobatidis in free-living and apparently healthy adult frogs from the Brazilian Atlant...

  5. Higher temperature variability increases the impact of Batrachochytrium dendrobatidis and shifts interspecific interactions in tadpole mesocosms

    OpenAIRE

    Phineas T Hamilton; Richardson, Jean ML; Govindarajulu, Purnima; Anholt, Bradley R

    2012-01-01

    The emergence of amphibian chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd) has led to the decline and extinction of numerous amphibian species. Multiple studies have observed links between climatic factors and amphibian declines apparently caused by Bd. Using outdoor experimental mesocosms, we tested the response of red-legged frog (Rana aurora) tadpoles to increased variation in temperature, a component of climate linked to amphibian declines, and Bd exposure. We i...

  6. Global Amphibian Extinction Risk Assessment for the Panzootic Chytrid Fungus

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    Matthew C. Fisher

    2009-09-01

    Full Text Available Species are being lost at increasing rates due to anthropogenic effects, leading to the recognition that we are witnessing the onset of a sixth mass extinction. Emerging infectious disease has been shown to increase species loss and any attempts to reduce extinction rates need to squarely confront this challenge. Here, we develop a procedure for identifying amphibian species that are most at risk from the effects of chytridiomycosis by combining spatial analyses of key host life-history variables with the pathogen's predicted distribution. We apply our rule set to the known global diversity of amphibians in order to prioritize pecies that are most at risk of loss from disease emergence. This risk assessment shows where limited conservation funds are best deployed in order to prevent further loss of species by enabling ex situ amphibian salvage operations and focusing any potential disease mitigation projects.

  7. Early 1900 s detection of Batrachochytrium dendrobatidis in Korean amphibians.

    Science.gov (United States)

    Fong, Jonathan J; Cheng, Tina L; Bataille, Arnaud; Pessier, Allan P; Waldman, Bruce; Vredenburg, Vance T

    2015-01-01

    The pathogenic fungus Batrachochytrium dendrobatidis (Bd) is a major conservation concern because of its role in decimating amphibian populations worldwide. We used quantitative PCR to screen 244 museum specimens from the Korean Peninsula, collected between 1911 and 2004, for the presence of Bd to gain insight into its history in Asia. Three specimens of Rugosa emeljanovi (previously Rana or Glandirana rugosa), collected in 1911 from Wonsan, North Korea, tested positive for Bd. Histology of these positive specimens revealed mild hyperkeratosis - a non-specific host response commonly found in Bd-infected frogs - but no Bd zoospores or zoosporangia. Our results indicate that Bd was present in Korea more than 100 years ago, consistent with hypotheses suggesting that Korean amphibians may be infected by endemic Asian Bd strains. PMID:25738656

  8. Early 1900 s detection of Batrachochytrium dendrobatidis in Korean amphibians.

    Directory of Open Access Journals (Sweden)

    Jonathan J Fong

    Full Text Available The pathogenic fungus Batrachochytrium dendrobatidis (Bd is a major conservation concern because of its role in decimating amphibian populations worldwide. We used quantitative PCR to screen 244 museum specimens from the Korean Peninsula, collected between 1911 and 2004, for the presence of Bd to gain insight into its history in Asia. Three specimens of Rugosa emeljanovi (previously Rana or Glandirana rugosa, collected in 1911 from Wonsan, North Korea, tested positive for Bd. Histology of these positive specimens revealed mild hyperkeratosis - a non-specific host response commonly found in Bd-infected frogs - but no Bd zoospores or zoosporangia. Our results indicate that Bd was present in Korea more than 100 years ago, consistent with hypotheses suggesting that Korean amphibians may be infected by endemic Asian Bd strains.

  9. Do frogs get their kicks on Route 66? Continental U.S. transect reveals spatial and temporal patterns of Batrachochytrium dendrobatidis infection.

    Directory of Open Access Journals (Sweden)

    Michael J Lannoo

    Full Text Available The chytrid fungus Batrachochytrium dendrobatidis (Bd has been devastating amphibians globally. Two general scenarios have been proposed for the nature and spread of this pathogen: Bd is an epidemic, spreading as a wave and wiping out individuals, populations, and species in its path; and Bd is endemic, widespread throughout many geographic regions on every continent except Antarctica. To explore these hypotheses, we conducted a transcontinental transect of United States Department of Defense (DoD installations along U.S. Highway 66 from California to central Illinois, and continuing eastward to the Atlantic Seaboard along U.S. Interstate 64 (in sum from Marine Corps Base Camp Pendleton in California to Naval Air Station Oceana in Virginia. We addressed the following questions: 1 Does Bd occur in amphibian populations on protected DoD environments? 2 Is there a temporal pattern to the presence of Bd? 3 Is there a spatial pattern to the presence of Bd? and 4 In these limited human-traffic areas, is Bd acting as an epidemic (i.e., with evidence of recent introduction and/or die-offs due to chytridiomycosis, or as an endemic (present without clinical signs of disease? Bd was detected on 13 of the 15 bases sampled. Samples from 30 amphibian species were collected (10% of known United States' species; half (15 tested Bd positive. There was a strong temporal (seasonal component; in total, 78.5% of all positive samples came in the first (spring/early-summer sampling period. There was also a strong spatial component--the eleven temperate DoD installations had higher prevalences of Bd infection (20.8% than the four arid (<60 mm annual precipitation bases (8.5%. These data support the conclusion that Bd is now widespread, and promote the idea that Bd can today be considered endemic across much of North America, extending from coast-to-coast, with the exception of remote pockets of naïve populations.

  10. Assessing the ability of swab data to determine the true burden of infection for the amphibian pathogen Batrachochytrium dendrobatidis

    OpenAIRE

    Clare, F.; Daniel, O; Garner, T.; Fisher, M.

    2016-01-01

    Batrachochytrium dendrobatidis (Bd) is a pathogenic fungus which causes the disease chytridiomycosis in amphibians by infecting the animals’ epidermis. The most commonly applied method for the detection of Bd is the use of a sterile swab, rubbed over the keratinized areas of an amphibian and then processed to yield DNA for detection by qPCR. This method has been used to infer a threshold of lethal infection in some species; however, how reliable and reproducible the swabbing method is at dete...

  11. A non-invasive stress assay shows that tadpole populations infected with Batrachochytrium dendrobatidis have elevated corticosterone levels

    OpenAIRE

    Gabor, Caitlin R.; Fisher, Matthew C; Bosch, Jaime

    2013-01-01

    Batrachochytrium dendrobatidis (Bd) is a fungus that causes the disease chytridiomycosis and is associated with widespread amphibian declines. Populations vary in their susceptibility to Bd infections, and the virulence of the infecting lineage can also vary. Both of these factors may manifest as a differential physiological stress response. In addition, variation in disease susceptibility across amphibian populations may be influenced by immunosuppression caused by chronic stress imposed by ...

  12. Phylogeny and biogeography of an uncultured clade of snow chytrids.

    Science.gov (United States)

    Naff, C S; Darcy, J L; Schmidt, S K

    2013-10-01

    Numerous studies have shown that snow can contain a diverse array of algae known as 'snow algae'. Some reports also indicate that parasites of algae (e.g. chytrids) are also found in snow, but efforts to phylogenetically identify 'snow chytrids' have not been successful. We used culture-independent molecular approaches to phylogenetically identify chytrids that are common in long-lived snowpacks of Colorado and Europe. The most remarkable finding of the present study was the discovery of a new clade of chytrids that has representatives in snowpacks of Colorado and Switzerland and cold sites in Nepal and France, but no representatives from warmer ecosystems. This new clade ('Snow Clade 1' or SC1) is as deeply divergent as its sister clade, the Lobulomycetales, and phylotypes of SC1 show significant (P snow chytrids were phylogenetically shown to be in the order Rhizophydiales, a group with known algal parasites and saprotrophs. We suggest that these newly discovered snow chytrids are important components of snow ecosystems where they contribute to snow food-web dynamics and the release of nutrients due to their parasitic and saprotrophic activities. PMID:23551529

  13. Chytrids dominate arctic marine fungal communities.

    Science.gov (United States)

    Hassett, B T; Gradinger, R

    2016-06-01

    Climate change is altering Arctic ecosystem structure by changing weather patterns and reducing sea ice coverage. These changes are increasing light penetration into the Arctic Ocean that are forecasted to increase primary production; however, increased light can also induce photoinhibition and cause physiological stress in algae and phytoplankton that can favour disease development. Fungi are voracious parasites in many ecosystems that can modulate the flow of carbon through food webs, yet are poorly characterized in the marine environment. We provide the first data from any marine ecosystem in which fungi in the Chytridiomycota dominate fungal communities and are linked in their occurrence to light intensities and algal stress. Increased light penetration stresses ice algae and elevates disease incidence under reduced snow cover. Our results show that chytrids dominate Arctic marine fungal communities and have the potential to rapidly change primary production patterns with increased light penetration. PMID:26754171

  14. 'Salamander plague' on Britain's doorstep.

    Science.gov (United States)

    Mills, Georgina

    2015-01-24

    Chytridiomycosis can cause mass declines in amphibians, and the chytrid fungus Batrachochytrium dendrobatidis is the classic cause of this disease. However, recently, a second strain of chytrid fungus has emerged in Europe, resulting in major declines in fire salamanders. The Zoological Society of London (ZSL) discussed this, and the implications for the UK, at a meeting in December in London. Georgina Mills reports. PMID:25614547

  15. Unexpected rarity of the pathogen Batrachochytrium dendrobatidis in Appalachian Plethodon Salamanders: 1957-2011.

    Directory of Open Access Journals (Sweden)

    Carly Muletz

    Full Text Available Widespread population declines in terrestrial Plethodon salamanders occurred by the 1980s throughout the Appalachian Mountains, the center of global salamander diversity, with no evident recovery. We tested the hypothesis that the historic introduction and spread of the pathogenic fungus Batrachochytrium dendrobatidis (Bd into the eastern US was followed by Plethodon population declines. We expected to detect elevated prevalence of Bd prior to population declines as observed for Central American plethodontids. We tested 1,498 Plethodon salamanders of 12 species (892 museum specimens, 606 wild individuals for the presence of Bd, and tested 94 of those for Batrachochytrium salamandrivorans (Bs and for ranavirus. Field samples were collected in 2011 from 48 field sites across a 767 km transect. Historic samples from museum specimens were collected at five sites with the greatest number and longest duration of collection (1957-987, four of which were sampled in the field in 2011. None of the museum specimens were positive for Bd, but four P. cinereus from field surveys were positive. The overall Bd prevalence from 1957-2011 for 12 Plethodon species sampled across a 757 km transect was 0.2% (95% CI 0.1-0.7%. All 94 samples were negative for Bs and ranavirus. We conclude that known amphibian pathogens are unlikely causes for declines in these Plethodon populations. Furthermore, these exceptionally low levels of Bd, in a region known to harbor Bd, may indicate that Plethodon specific traits limit Bd infection.

  16. Freeze tolerance of soil chytrids from temperate climates in Australia.

    Science.gov (United States)

    Gleason, Frank H; Letcher, Peter M; McGee, Peter A

    2008-08-01

    Very little is known about the capacity of soil chytrids to withstand freezing in the field. Tolerance to freezing was tested in 21 chytrids isolated from cropping and undisturbed soils in temperate Australia. Samples of thalli grown on peptone-yeast-glucose (PYG) agar were incubated for seven days at -15 degrees C. Recovery of growth after thawing and transferring to fresh medium at 20 degrees C indicated survival. All isolates in the Blastocladiales and Spizellomycetales survived freezing in all tests. All isolates in the Chytridiales also survived freezing in some tests. None of the isolates in the Rhizophydiales survived freezing in any of the tests. However, some isolates in the Rhizophydiales recovered growth after freezing if they were grown on PYG agar supplemented with either 1% sodium chloride or 1% glycerol prior to freezing. After freezing, the morphology of the thalli of all isolates was observed under LM. In those isolates that recovered growth after transfer to fresh media, mature zoosporangia were observed in the monocentric isolates and resistant sporangia or resting spores in the polycentric isolates. Encysted zoospores in some monocentric isolates also survived freezing. In some of the experiments the freezing and thawing process caused visible structural damage to the thalli. The production of zoospores after freezing and thawing was also used as an indicator of freeze tolerance. The chytrids in this study responded differently to freezing. These data add significantly to our limited knowledge of freeze tolerance in chytrids but leave many questions unanswered. PMID:18550351

  17. Distribution of the amphibian pathogen Batrachochytrium dendrobatidis in the Pacific Northwestern USA

    Science.gov (United States)

    Pearl, Christopher A.; Bull, E.L.; Green, D.E.; Bowerman, Jay; Adams, Michael J.; Hyatt, A.; Wente, W.

    2007-01-01

    Chytridiomycosis (infection by the fungus Batrachochytrium dendrobatidis) has been associated with amphibian declines in at least four continents. We report results of disease screens from 210 pond-breeding amphibians from 37 field sites in Oregon and Washington. We detected B. dendrobatidis on 28% of sampled amphibians, and we found a?Y 1 detection of B. dendrobatidis from 43% of sites. Four of seven species tested positive for B. dendrobatidis, including the Northern Red-Legged Frog (Rana aurora), Columbia Spotted Frog (Rana luteiventris), and Oregon Spotted Frog (Rana pretiosa). We also detected B. dendrobatidis in nonnative American Bullfrogs (Rana catesbeiana) from six sites in western and central Oregon. Our study and other recently published findings suggest that B. dendrobatidis has few geographic and host taxa limitations among North American anurans. Further research on virulence, transmissibility, persistence, and interactions with other stressors is needed to assess the potential impact of B. dendrobatidis on Pacific Northwestern amphibians.

  18. Duplex Real-Time PCR for Rapid Simultaneous Detection of Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans in Amphibian Samples

    OpenAIRE

    Blooi, M.; Pasmans, F.; Longcore, J. E.; Spitzen-van der Sluijs, A.; Vercammen, F.; Martel, A

    2013-01-01

    Chytridiomycosis is a lethal fungal disease contributing to declines and extinctions of amphibian species worldwide. The currently used molecular screening tests for chytridiomycosis fail to detect the recently described species Batrachochytrium salamandrivorans. In this study, we present a duplex real-time PCR that allows the simultaneous detection of B. salamandrivorans and Batrachochytrium dendrobatidis. With B. dendrobatidis- and B. salamandrivorans-specific primers and probes, detection ...

  19. Parasitic chytrids sustain zooplankton growth during inedible algal bloom.

    Science.gov (United States)

    Rasconi, Serena; Grami, Boutheina; Niquil, Nathalie; Jobard, Marlène; Sime-Ngando, Télesphore

    2014-01-01

    This study assesses the quantitative impact of parasitic chytrids on the planktonic food web of two contrasting freshwater lakes during different algal bloom situations. Carbon-based food web models were used to investigate the effects of chytrids during the spring diatom bloom in Lake Pavin (oligo-mesotrophic) and the autumn cyanobacteria bloom in Lake Aydat (eutrophic). Linear inverse modeling was employed to estimate undetermined flows in both lakes. The Monte Carlo Markov chain linear inverse modeling procedure provided estimates of the ranges of model-derived fluxes. Model results confirm recent theories on the impact of parasites on food web function through grazers and recyclers. During blooms of "inedible" algae (unexploited by planktonic herbivores), the epidemic growth of chytrids channeled 19-20% of the primary production in both lakes through the production of grazer exploitable zoospores. The parasitic throughput represented 50% and 57% of the zooplankton diet, respectively, in the oligo-mesotrophic and in the eutrophic lakes. Parasites also affected ecological network properties such as longer carbon path lengths and loop strength, and contributed to increase the stability of the aquatic food web, notably in the oligo-mesotrophic Lake Pavin. PMID:24904543

  20. Parasitic Chytrids sustain zooplankton growth during inedible algal bloom

    Directory of Open Access Journals (Sweden)

    SerenaRasconi

    2014-05-01

    Full Text Available This study assesses the quantitative impact of parasitic chytrids on the planktonic food web of two contrasting freshwater lakes during different algal bloom situations. Carbon-based food web models were used to investigate the effects of chytrids during the spring diatom bloom of Lake Pavin (oligo-mesotrophic and the autumn cyanobacteria bloom of Lake Aydat (eutrophic. Linear inverse modelling was employed to estimate undetermined flows in both lakes. The Monte Carlo Markov chain linear inverse modelling procedure provided estimates of the ranges of model-derived fluxes. Model results confirm recent theories on the probable impact of parasites on food web function as grazers and recyclers. During blooms of “inedible” algae (unexploited by planktonic herbivores, the epidemic growth of chytrids channelled 19-20% of the primary production in both lakes through the production of grazer-exploitable zoospores. The parasitic throughput represents 50 and 57% of the zooplankton diet respectively in the oligo-mesotrophic and in the eutrophic lakes. Parasites also affected ecological network properties as longer carbon path lengths and loop strength, and contributed to increase the stability of the aquatic food web, notably in the oligo-mesotrophic Lake Pavin.# The first two authors contributed equally to this work

  1. Motile zoospores of Batrachochytrium dendrobatidis move away from antifungal metabolites produced by amphibian skin bacteria.

    Science.gov (United States)

    Lam, Brianna A; Walton, D Brian; Harris, Reid N

    2011-03-01

    Chytridiomycosis is an amphibian skin disease that threatens amphibian biodiversity worldwide. The fungal agent of chytridiomycosis is Batrachochytrium dendrobatidis. There is considerable variation in disease outcomes such that some individuals and populations co-exist with the fungus and others quickly succumb to disease. Amphibians in populations that co-exist with the B. dendrobatidis have sublethal infections on their skins. Symbiotic skin bacteria have been shown in experiments and surveys to play a role in protecting amphibians from chytridiomycosis. Little is known about the mechanisms that antifungal skin bacteria use to ameliorate the effects of B. dendrobatidis. In this study, we identified that B. dendrobatidis isolate JEL 310 zoospores display chemotaxis, in the presence of two bacterially-produced metabolites (2,4-diacetylphloroglucinol and indole-3-carboxaldehyde). In the presence of either metabolite, B. dendrobatidis zoospores move more frequently away from the metabolite. Using parameters estimated from this study, a simple stochastic model of a random walk on a lattice was evaluated. The model shows that these individual behaviors over short time-scales directly lead to population behaviors over long time-scales, such that most zoospores will escape, or not infect a tryptone substrate containing the bacterially-produced metabolite, whereas many zoospores will infect the tryptone substrate containing no metabolite. These results suggest that amphibians that have skin bacteria produce antifungal metabolites that might be able to keep B. dendrobatidis infections below the lethal threshold and thus are able to co-exist with the fungus. PMID:21769695

  2. Amphibians acquire resistance to live and dead fungus overcoming fungal immunosuppression

    OpenAIRE

    McMahon, Taegan A.; Brittany F Sears; Venesky, Matthew D.; Bessler, Scott M.; Brown, Jenise M.; Deutsch, Kaitlin; Halstead, Neal T.; Lentz, Garrett; Tenouri, Nadia; Young, Suzanne; Civitello, David J.; Ortega, Nicole; Fites, J. Scott; Reinert, Laura K.; Rollins-Smith, Louise A.

    2014-01-01

    Emerging fungal pathogens pose a greater threat to biodiversity than any other parasitic group1, causing declines of many taxa, including bats, corals, bees, snakes and amphibians1–4. Currently, there is little evidence that wild animals can acquire resistance to these pathogens5. Batrachochytrium dendrobatidis is a pathogenic fungus implicated in the recent global decline of amphibians6. Here we demonstrate that three species of amphibians can acquire behavioural or immunological resistance ...

  3. Fungus Amongus

    Science.gov (United States)

    Wakeley, Deidra

    2005-01-01

    This role-playing simulation is designed to help teach middle level students about the typical lifecycle of a fungus. In this interactive simulation, students assume the roles of fungi, spores, living and dead organisms, bacteria, and rain. As they move around a playing field collecting food and water chips, they discover how the organisms…

  4. 75 FR 13720 - Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition to List the Striped...

    Science.gov (United States)

    2010-03-23

    ... possible listing under the Act as a Category 2 candidate species (59 FR 58982). In the February 28, 1996, notice (61 FR 7596), the Service discontinued the designation of Category 2 species as candidates and... newts. Mitchell (2002, p. 3) documented the chytrid fungus (Batrachochytrium dendrobatidis) which...

  5. The Search for Violacein-Producing Microbes to Combat Batrachochytrium dendrobatidis: A Collaborative Research Project between Secondary School and College Research Students†

    Science.gov (United States)

    Agate, Larra; Beam, Deborah; Bucci, Collen; Dukashin, Yegor; Jo’Beh, Raneem; O’Brien, Kelsey; Jude, Brooke A.

    2016-01-01

    In this citizen science–aided, college laboratory–based microbiology research project, secondary school students collaborate with college research students on an investigation centered around bacterial species in the local watershed. This study specifically investigated the prevalence of violacein-producing bacterial isolates, as violacein has been demonstrated as a potential bioremediation treatment for outbreaks of the worldwide invasive chytrid, Batrachochytrium dendrobatidis (Bd). The impact of this invasion has been linked to widespread amphibian decline, and tracking of the spread of Bd is currently ongoing. Secondary school students participated in this research project by sterilely collecting water samples from a local watershed, documenting the samples, and completing the initial sample plating in a BSL1 environment. In the second phase of this project, trained college students working in courses and as research assistants in the academic year and summer term in a BSL2 laboratory facility were able to use physiological, biochemical, and molecular techniques to further identify individual isolates as well as characterize their properties. Collaboration between these learning spaces provides an increased interest in the community for environmentally relevant research projects and allows for an expansion of the research team to increase study robustness. Journal of Microbiology & Biology Education PMID:27047594

  6. The Search for Violacein-Producing Microbes to Combat Batrachochytrium dendrobatidis: A Collaborative Research Project between Secondary School and College Research Students.

    Science.gov (United States)

    Agate, Larra; Beam, Deborah; Bucci, Collen; Dukashin, Yegor; Jo'Beh, Raneem; O'Brien, Kelsey; Jude, Brooke A

    2016-03-01

    In this citizen science-aided, college laboratory-based microbiology research project, secondary school students collaborate with college research students on an investigation centered around bacterial species in the local watershed. This study specifically investigated the prevalence of violacein-producing bacterial isolates, as violacein has been demonstrated as a potential bioremediation treatment for outbreaks of the worldwide invasive chytrid, Batrachochytrium dendrobatidis (Bd). The impact of this invasion has been linked to widespread amphibian decline, and tracking of the spread of Bd is currently ongoing. Secondary school students participated in this research project by sterilely collecting water samples from a local watershed, documenting the samples, and completing the initial sample plating in a BSL1 environment. In the second phase of this project, trained college students working in courses and as research assistants in the academic year and summer term in a BSL2 laboratory facility were able to use physiological, biochemical, and molecular techniques to further identify individual isolates as well as characterize their properties. Collaboration between these learning spaces provides an increased interest in the community for environmentally relevant research projects and allows for an expansion of the research team to increase study robustness. Journal of Microbiology & Biology Education. PMID:27047594

  7. The Search for Violacein-Producing Microbes to Combat Batrachochytrium dendrobatidis: A Collaborative Research Project between Secondary School and College Research Students

    Directory of Open Access Journals (Sweden)

    Larra Agate

    2015-10-01

    Full Text Available In this citizen science–aided, college laboratory–based microbiology research project, secondary school students collaborate with college research students on an investigation centered around bacterial species in the local watershed. This study specifically investigated the prevalence of violacein-producing bacterial isolates, as violacein has been demonstrated as a potential bioremediation treatment for outbreaks of the worldwide invasive chytrid, Batrachochytrium dendrobatidis (Bd. The impact of this invasion has been linked to widespread amphibian decline, and tracking of the spread of Bd is currently ongoing. Secondary school students participated in this research project by sterilely collecting water samples from a local watershed, documenting the samples, and completing the initial sample plating in a BSL1 environment. In the second phase of this project, trained college students working in courses and as research assistants in the academic year and summer term in a BSL2 laboratory facility were able to use physiological, biochemical, and molecular techniques to further identify individual isolates as well as characterize their properties. Collaboration between these learning spaces provides an increased interest in the community for environmentally relevant research projects and allows for an expansion of the research team to increase study robustness.

  8. A new genus and family for the misclassified chytrid, Rhizophlyctis harderi.

    Science.gov (United States)

    Powell, Martha J; Letcher, Peter M; Chambers, James G; Roychoudhury, Sonali

    2015-01-01

    A chytrid first discovered in Mediterranean sands and called Rhizophlyctis harderi was classified in the genus Rhizophlyctis based on its interbiotic vegetative thalli with multiple rhizoidal axes and resting thalli with tufts of rhizoid-like appendages. Developmental, electron microscopic and molecular analyses, however, have brought into question the proper placement of this chytrid. Because its original description was in German and not Latin, the name R. harderi is not validly published. We found that this chytrid produces three thallus forms that could place it in three different morpho-genera: Rhizophydium, Phlyctochytrium or Rhizophlyctis. The ultrastructural architecture of its zoospore is different from that of zoospores of Rhizophlyctis rosea, the type species for Rhizophlyctis, and shares zoospore ultrastructural characteristics with the Rhizophydiales. Zoospores of this chytrid exhibit a distinctive kinetosome-associated structure (KAS), a curved shield bridged to two of the kinetosomal triplets and a layered cap anterior to the kinetosome. Phylogenetic analyses of nuc rDNA also support the placement of this chytrid in the Rhizophydiales and not in the Rhizophlyctidales. Given its molecularly based phylogenetic placement and its distinctive zoospore architecture, we describe this chytrid in a new genus, Uebelmesseromyces, in the Rhizophydiales and erect Uebelmesseromycetaceae as a new family to accommodate it. PMID:25572098

  9. Occurrence of the amphibian pathogen Batrachochytrium dendrobatidis in the Pacific Northwest

    Science.gov (United States)

    Pearl, C.A.; Bull, E.L.; Green, D.E.; Bowerman, J.; Adams, M.J.; Hyatt, A.; Wente, W.H.

    2007-01-01

    Chytridiomycosis (infection by the fungus Batrachochytrium dendrobatidis) has been associated with amphibian declines in at least four continents. We report results of disease screens from 210 pond-breeding amphibians from 37 field sites in Oregon and Washington. We detected B. dendrobatidis on 28% of sampled amphibians, and we found ??? 1 detection of B. dendrobatidis from 43% of sites. Four of seven species tested positive for B. dendrobatidis, including the Northern Red-Legged Frog (Rana aurora), Columbia Spotted Frog (Rana luteiventris), and Oregon Spotted Frog (Rana pretiosa). We also detected B. dendrobatidis in nonnative American Bullfrogs (Rana catesbeiana) from six sites in western and central Oregon. Our study and other recently published findings suggest that B. dendrobatidis has few geographic and host taxa limitations among North American anurans. Further research on virulence, transmissibility, persistence, and interactions with other stressors is needed to assess the potential impact of B. dendrobatidis on Pacific Northwestern amphibians. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  10. Batrachochytrium dendrobatidis exposure effects on foraging efficiencies and body size in anuran tadpoles.

    Science.gov (United States)

    Hanlon, Shane M; Lynch, Kyle J; Kerby, Jake; Parris, Matthew J

    2015-01-15

    Chytridiomycosis, the amphibian disease caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), is fatal to adults of many species. Bd is largely sublethal to amphibian larvae; however, it is known to reduce larval (i.e. tadpole) growth rates, with possible long-term effects on population dynamics and fitness. We conducted an experiment to test how Bd altered southern leopard frog Lithobates sphenocephalus tadpole mouthpart damage, percentage of food ingested, and subsequent body size. We examined our results using path analyses. We hypothesized that Bd would increase mouthpart damage, causing less food to be ingested, and ultimately reduce body size. In our model, both Bd exposure and increased mouthpart damage significantly reduced food ingested and subsequent body size. However, our study provides evidence against the long-standing hypothesis of mouthpart damage as a pathway for Bd-induced reductions in larval group. Here we provide evidence for reduced foraging efficiency (percentage of food ingested) as a mechanism for Bd-induced reductions in body size. This work highlights the importance of studying the sublethal effects of Bd on larval amphibians. PMID:25590774

  11. Skin bacterial diversity of Panamanian frogs is associated with host susceptibility and presence of Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Rebollar, Eria A; Hughey, Myra C; Medina, Daniel; Harris, Reid N; Ibáñez, Roberto; Belden, Lisa K

    2016-07-01

    Symbiotic bacteria on amphibian skin can inhibit growth of the fungus Batrachochytrium dendrobatidis (Bd) that has caused dramatic population declines and extinctions of amphibians in the Neotropics. It remains unclear how the amphibians' skin microbiota is influenced by environmental bacterial reservoirs, host-associated factors such as susceptibility to pathogens, and pathogen presence in tropical amphibians. We sampled skin bacteria from five co-occurring frog species that differ in Bd susceptibility at one Bd-naive site, and sampled one of the non-susceptible species from Bd-endemic and Bd-naive sites in Panama. We hypothesized that skin bacterial communities (1) would be distinct from the surrounding environment regardless of the host habitat, (2) would differ between Bd susceptible and non-susceptible species and (3) would differ on hosts in Bd-naive and Bd-endemic sites. We found that skin bacterial communities were enriched in bacterial taxa that had low relative abundances in the environment. Non-susceptible species had very similar skin bacterial communities that were enriched in particular taxa such as the genera Pseudomonas and Acinetobacter. Bacterial communities of Craugastor fitzingeri in Bd-endemic sites were less diverse than in the naive site, and differences in community structure across sites were explained by changes in relative abundance of specific bacterial taxa. Our results indicate that skin microbial structure was associated with host susceptibility to Bd and might be associated to the history of Bd presence at different sites. PMID:26744810

  12. Distribution limits of Batrachochytrium dendrobatidis: a case study in the Rocky Mountains, USA.

    Science.gov (United States)

    Hossack, B.R.; Muths, E.; Anderson, C.W.; Kirshtein, J.D.; Corn, P.S.

    2009-01-01

    Knowledge of the environmental constraints on a pathogen is critical to predicting its dynamics and effects on populations. Batrachochytrium dendrobatidis (Bd), an aquatic fungus that has been linked with widespread amphibian declines, is ubiquitous in the Rocky Mountains. As part of assessing the distribution limits of Bd in our study area, we sampled the water column and sediments for Bd zoospores in 30 high-elevation water bodies that lacked amphibians. All water bodies were in areas where Bd has been documented from neighboring, lower-elevation areas. We targeted areas lacking amphibians because existence of Bd independent of amphibians would have both ecologic and management implications. We did not detect Bd, which supports the hypothesis that it does not live independently of amphibians. However, assuming a detection sensitivity of 59.5% (based on sampling of water where amphibians tested positive for Bd), we only had 95% confidence of detecting Bd if it was in > or =16% of our sites. Further investigation into potential abiotic reservoirs is needed, but our results provide a strategic step in determining the distributional and environmental limitations of Bd in our study region.

  13. Short-term exposure to warm microhabitats could explain amphibian persistence with Batrachochytrium dendrobatidis.

    Directory of Open Access Journals (Sweden)

    Joshua H Daskin

    Full Text Available Environmental conditions can alter the outcomes of symbiotic interactions. Many amphibian species have declined due to chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd, but many others persist despite high Bd infection prevalence. This indicates that Bd's virulence is lower, or it may even be a commensal, in some hosts. In the Australian Wet Tropics, chytridiomycosis extirpated Litoria nannotis from high-elevation rain forests in the early 1990 s. Although the species is recolonizing many sites, no population has fully recovered. Litoria lorica disappeared from all known sites in the early 1990 s and was thought globally extinct, but a new population was discovered in 2008, in an upland dry forest habitat it shares with L. nannotis. All frogs of both species observed during three population censuses were apparently healthy, but most carried Bd. Frogs perch on sun-warmed rocks in dry forest streams, possibly keeping Bd infections below the lethal threshold attained in cooler rain forests. We tested whether short-term elevated temperatures can hamper Bd growth in vitro over one generation (four days. Simulating the temperatures available to frogs on strongly and moderately warmed rocks in dry forests, by incubating cultures at 33°C for one hour daily, reduced Bd growth below that of Bd held at 15°C constantly (representing rain forest habitats. Even small decreases in the exponential growth rate of Bd on hosts may contribute to the survival of frogs in dry forests.

  14. Characterization of the Carbohydrate Binding Module 18 gene family in the amphibian pathogen Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Liu, Peng; Stajich, Jason E

    2015-04-01

    Batrachochytrium dendrobatidis (Bd) is the causative agent of chytridiomycosis responsible for worldwide decline in amphibian populations. Previous analysis of the Bd genome revealed a unique expansion of the carbohydrate-binding module family 18 (CBM18) predicted to be a sub-class of chitin recognition domains. CBM expansions have been linked to the evolution of pathogenicity in a variety of fungal species by protecting the fungus from the host. Based on phylogenetic analysis and presence of additional protein domains, the gene family can be classified into 3 classes: Tyrosinase-, Deacetylase-, and Lectin-like. Examination of the mRNA expression levels from sporangia and zoospores of nine of the cbm18 genes found that the Lectin-like genes had the highest expression while the Tyrosinase-like genes showed little expression, especially in zoospores. Heterologous expression of GFP-tagged copies of four CBM18 genes in Saccharomyces cerevisiae demonstrated that two copies containing secretion signal peptides are trafficked to the cell boundary. The Lectin-like genes cbm18-ll1 and cbm18-ll2 co-localized with the chitinous cell boundaries visualized by staining with calcofluor white. In vitro assays of the full length and single domain copies from CBM18-LL1 demonstrated chitin binding and no binding to cellulose or xylan. Expressed CBM18 domain proteins were demonstrated to protect the fungus, Trichoderma reeseii, in vitro against hydrolysis from exogenously added chitinase, likely by binding and limiting exposure of fungal chitin. These results demonstrate that cbm18 genes can play a role in fungal defense and expansion of their copy number may be an important pathogenicity factor of this emerging infectious disease of amphibians. PMID:25819009

  15. Amphibian-killing chytrid in Brazil comprises both locally endemic and globally expanding populations.

    Science.gov (United States)

    Jenkinson, T S; Betancourt Román, C M; Lambertini, C; Valencia-Aguilar, A; Rodriguez, D; Nunes-de-Almeida, C H L; Ruggeri, J; Belasen, A M; da Silva Leite, D; Zamudio, K R; Longcore, J E; Toledo, F L; James, T Y

    2016-07-01

    Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), is the emerging infectious disease implicated in recent population declines and extinctions of amphibian species worldwide. Bd strains from regions of disease-associated amphibian decline to date have all belonged to a single, hypervirulent clonal genotype (Bd-GPL). However, earlier studies in the Atlantic Forest of southeastern Brazil detected a novel, putatively enzootic lineage (Bd-Brazil), and indicated hybridization between Bd-GPL and Bd-Brazil. Here, we characterize the spatial distribution and population history of these sympatric lineages in the Brazilian Atlantic Forest. To investigate the genetic structure of Bd in this region, we collected and genotyped Bd strains along a 2400-km transect of the Atlantic Forest. Bd-Brazil genotypes were restricted to a narrow geographic range in the southern Atlantic Forest, while Bd-GPL strains were widespread and largely geographically unstructured. Bd population genetics in this region support the hypothesis that the recently discovered Brazilian lineage is enzootic in the Atlantic Forest of Brazil and that Bd-GPL is a more recently expanded invasive. We collected additional hybrid isolates that demonstrate the recurrence of hybridization between panzootic and enzootic lineages, thereby confirming the existence of a hybrid zone in the Serra da Graciosa mountain range of Paraná State. Our field observations suggest that Bd-GPL may be more infective towards native Brazilian amphibians, and potentially more effective at dispersing across a fragmented landscape. We also provide further evidence of pathogen translocations mediated by the Brazilian ranaculture industry with implications for regulations and policies on global amphibian trade. PMID:26939017

  16. Seasonal Variation in Population Abundance and Chytrid Infection in Stream-Dwelling Frogs of the Brazilian Atlantic Forest

    Science.gov (United States)

    Ruggeri, Joice; Longo, Ana V.; Gaiarsa, Marília P.; Alencar, Laura R. V.; Lambertini, Carolina; Leite, Domingos S.; Carvalho-e-Silva, Sergio P.; Zamudio, Kelly R.; Toledo, Luís Felipe; Martins, Marcio

    2015-01-01

    Enigmatic amphibian declines were first reported in southern and southeastern Brazil in the late 1980s and included several species of stream-dwelling anurans (families Hylodidae and Cycloramphidae). At that time, we were unaware of the amphibian-killing fungus Batrachochytrium dendrobatidis (Bd); therefore, pollution, habitat loss, fragmentation and unusual climatic events were hypothesized as primary causes of these declines. We now know that multiple lineages of Bd have infected amphibians of the Brazilian Atlantic forest for over a century, yet declines have not been associated specifically with Bd outbreaks. Because stream-dwelling anurans occupy an environmental hotspot ideal for disease transmission, we investigated temporal variation in population and infection dynamics of three stream-adapted species (Hylodes asper, H. phyllodes, and Cycloramphus boraceiensis) on the northern coast of São Paulo state, Brazil. We surveyed standardized transects along streams for four years, and show that fluctuations in the number of frogs correlate with specific climatic variables that also increase the likelihood of Bd infections. In addition, we found that Bd infection probability in C. boraceiensis, a nocturnal species, was significantly higher than in Hylodes spp., which are diurnal, suggesting that the nocturnal activity may either facilitate Bd zoospore transmission or increase susceptibility of hosts. Our findings indicate that, despite long-term persistence of Bd in Brazil, some hosts persist with seasonally variable infections, and thus future persistence in the face of climate change will depend on the relative effect of those changes on frog recruitment and pathogen proliferation. PMID:26161777

  17. Seasonal Variation in Population Abundance and Chytrid Infection in Stream-Dwelling Frogs of the Brazilian Atlantic Forest.

    Directory of Open Access Journals (Sweden)

    Joice Ruggeri

    Full Text Available Enigmatic amphibian declines were first reported in southern and southeastern Brazil in the late 1980s and included several species of stream-dwelling anurans (families Hylodidae and Cycloramphidae. At that time, we were unaware of the amphibian-killing fungus Batrachochytrium dendrobatidis (Bd; therefore, pollution, habitat loss, fragmentation and unusual climatic events were hypothesized as primary causes of these declines. We now know that multiple lineages of Bd have infected amphibians of the Brazilian Atlantic forest for over a century, yet declines have not been associated specifically with Bd outbreaks. Because stream-dwelling anurans occupy an environmental hotspot ideal for disease transmission, we investigated temporal variation in population and infection dynamics of three stream-adapted species (Hylodes asper, H. phyllodes, and Cycloramphus boraceiensis on the northern coast of São Paulo state, Brazil. We surveyed standardized transects along streams for four years, and show that fluctuations in the number of frogs correlate with specific climatic variables that also increase the likelihood of Bd infections. In addition, we found that Bd infection probability in C. boraceiensis, a nocturnal species, was significantly higher than in Hylodes spp., which are diurnal, suggesting that the nocturnal activity may either facilitate Bd zoospore transmission or increase susceptibility of hosts. Our findings indicate that, despite long-term persistence of Bd in Brazil, some hosts persist with seasonally variable infections, and thus future persistence in the face of climate change will depend on the relative effect of those changes on frog recruitment and pathogen proliferation.

  18. Invasion of the Fungal Pathogen Batrachochytrium dendrobatidis on California Islands.

    Science.gov (United States)

    Yap, Tiffany A; Gillespie, Lauren; Ellison, Silas; Flechas, Sandra V; Koo, Michelle S; Martinez, Ari E; Vredenburg, Vance T

    2016-03-01

    Batrachochytrium dendrobatidis (Bd), an amphibian fungal pathogen, has infected >500 species and caused extinctions or declines in >200 species worldwide. Despite over a decade of research, little is known about its invasion biology. To better understand this, we conducted a museum specimen survey (1910-1997) of Bd in amphibians on 11 California islands and found a pattern consistent with the emergence of Bd epizootics on the mainland, suggesting that geographic isolation did not prevent Bd invasion. We propose that suitable habitat, host diversity, and human visitation overcome isolation from the mainland and play a role in Bd invasion. PMID:26493624

  19. Over-wintering tadpoles of Mixophyes fasciolatus act as reservoir host for Batrachochytrium dendrobatidis.

    Directory of Open Access Journals (Sweden)

    Edward J Narayan

    Full Text Available Batrachochytrium dendrobatidis (Bd, a cutaneous amphibian fungus that causes the lethal disease chytridiomycosis, has been implicated as a cause of many amphibian declines. Bd can tolerate low temperatures with an optimum thermal range from 17-24°C. It has been shown that Bd infection may result in species extinction, avoiding the transmission threshold presented by density dependent transmission theory. Prevalence of Bd during autumn and winter has been shown to be as low as 0% in some species. It is currently unclear how Bd persists in field conditions and what processes result in carry-over between seasons. It has been hypothesised that overwintering tadpoles may host Bd between breeding seasons. The Great Barred Frog (Mixophyes fasciolatus is a common, stable and widespread species in Queensland, Australia, and is known to carry Bd. Investigation into Bd infection of different life stages of M. fasciolatus during seasonally low prevalence may potentially reveal persistence and carry-over methods between seasons. Metamorphs, juveniles, and adults were swabbed for Bd infection over three months (between March and May, 2011 at 5 sites of varying altitude (66 m-790 m. A total of 93 swabs were analysed using Polymerase Chain Reaction (PCR real-time analysis. PCR analysis showed 6 positive (1 excluded, 4 equivocal and 83 negative results for infection with Bd. Equivocal results were assumed to be negative using the precautionary principle. The 5 positive results consisted of 4 emerging (Gosner stage 43-45 metamorphs and 1 adult M. fasciolatus. Fisher's exact test on prevalence showed that the prevalence was significantly different between life stages. All positive results were sampled at high altitudes (790 m; however prevalence was not significantly different between altitudes. Infection of emerging metamorphs suggests that individuals were infected as tadpoles. We hypothesise that M. fasciolatus tadpoles carry Bd through seasons. Thus

  20. The use of singleplex and nested PCR to detect Batrachochytrium dendrobatidis in free-living frogs

    Directory of Open Access Journals (Sweden)

    Selene Dall'Acqua Coutinho

    2015-06-01

    Full Text Available Many microorganisms are able to cause diseases in amphibians, and in the past few years one of the most reported has been Batrachochytrium dendrobatidis. This fungus was first reported in Brazil in 2005; following this, other reports were made in specimens deposited in museum collections, captive and free-living frogs. The aim of this study was to compare singleplex and nested-PCR techniques to detect B. dendrobatidis in free-living and apparently healthy adult frogs from the Brazilian Atlantic Forest. The sample collection area was a protected government park, with no general entrance permitted and no management of the animals there. Swabs were taken from the skin of 107 animals without macroscopic lesions and they were maintained in ethanol p.a. Fungal DNA was extracted and identification of B. dendrobatidis was performed using singleplex and nested-PCR techniques, employing specific primers sequences. B. dendrobatidis was detected in 61/107 (57% and 18/107 (17% animals, respectively by nested and singleplex-PCR. Nested-PCR was statistically more sensible than the conventional for the detection of B. dendrobatidis (Chi-square = 37.1; α = 1% and the agreement between both techniques was considered just fair (Kappa = 0.27. The high prevalence obtained confirms that these fungi occur in free-living frogs from the Brazilian Atlantic Forest with no macroscopic lesions, characterizing the state of asymptomatic carrier. We concluded that the nested-PCR technique, due to its ease of execution and reproducibility, can be recommended as one of the alternatives in epidemiological surveys to detect B. dendrobatidis in healthy free-living frog populations.

  1. The Effect of Human Impact on Batrachochytrium dendrobatidis prevalence in Taricha torosa

    Science.gov (United States)

    Deng, V.; Macario, E.; Tumey, C.

    2014-12-01

    Batrachochytrium dendrobatidis (Bd) is emerging as a major cause of the amphibian extinction. As amphibians serve an important role as indicator species in their ecosystem and play a vital role in the food chain, Bd will not only affect the amphibian population but also the health of the environment. Bd is an aquatic fungus that blocks the porous skin of amphibians which interrupts electrolyte, gas and water transfer. This imbalances the electrolyte system which causes cells and organs to malfunction, therefore killing the amphibian. While frogs are more common for Bd, it is not often found in newts. However, Dr. Vance Vredenburg recently found an outbreak of Bd in Taricha torosa in Marin Headlands, California. This location was used in the research as the sample site with most human impact and was expected to have the highest prevalence according to the proposed hypothesis that more human impact will correspond with a higher prevalence of Bd. Decreasing the level of human impact, Fairfield Osborn Preserve and Galbreath Preserve were picked as the other sample sites. After the samples went through qPCR, all of them came back negative for Bd. These results did not support the hypothesis, however, it contributed data to explaining the dynamics of Bd when combined with Dr. Vance Vredenburg's data from 2 months earlier. Within the two months, there was a huge difference in the prevalence of Bd as it dropped from 88% to 0%. This shows that Taricha torosa does in fact get Bd. However, it is rarely detected because Bd is fast-acting and has high mortality rates. Therefore, it is least likely for current nonspecific surveys to swab the newts during a short but lethal Bd outbreak.

  2. The use of singleplex and nested PCR to detect Batrachochytrium dendrobatidis in free-living frogs.

    Science.gov (United States)

    Coutinho, Selene Dall'Acqua; Burke, Julieta Catarina; de Paula, Catia Dejuste; Rodrigues, Miguel Trefaut; Catão-Dias, José Luiz

    2015-06-01

    Many microorganisms are able to cause diseases in amphibians, and in the past few years one of the most reported has been Batrachochytrium dendrobatidis. This fungus was first reported in Brazil in 2005; following this, other reports were made in specimens deposited in museum collections, captive and free-living frogs. The aim of this study was to compare singleplex and nested-PCR techniques to detect B. dendrobatidis in free-living and apparently healthy adult frogs from the Brazilian Atlantic Forest. The sample collection area was a protected government park, with no general entrance permitted and no management of the animals there. Swabs were taken from the skin of 107 animals without macroscopic lesions and they were maintained in ethanol p.a. Fungal DNA was extracted and identification of B. dendrobatidis was performed using singleplex and nested-PCR techniques, employing specific primers sequences. B. dendrobatidis was detected in 61/107 (57%) and 18/107 (17%) animals, respectively by nested and singleplex-PCR. Nested-PCR was statistically more sensible than the conventional for the detection of B. dendrobatidis (Chi-square = 37.1; α = 1%) and the agreement between both techniques was considered just fair (Kappa = 0.27). The high prevalence obtained confirms that these fungi occur in free-living frogs from the Brazilian Atlantic Forest with no macroscopic lesions, characterizing the state of asymptomatic carrier. We concluded that the nested-PCR technique, due to its ease of execution and reproducibility, can be recommended as one of the alternatives in epidemiological surveys to detect B. dendrobatidis in healthy free-living frog populations. PMID:26273273

  3. Infection and transmission heterogeneity of a multi-host pathogen (Batrachochytrium dendrobatidis) within an amphibian community.

    Science.gov (United States)

    Fernández-Beaskoetxea, S; Bosch, J; Bielby, J

    2016-02-11

    The majority of parasites infect multiple hosts. As the outcome of the infection is different in each of them, most studies of wildlife disease focus on the few species that suffer the most severe consequences. However, the role that each host plays in the persistence and transmission of infection can be crucial to understanding the spread of a parasite and the risk it poses to the community. Current theory predicts that certain host species can modulate the infection in other species by amplifying or diluting both infection prevalence and infection intensity, both of which have implications for disease risk within those communities. The fungus Batrachochytrium dendrobatidis (Bd), the causal agent of the disease chytridiomycosis, has caused global amphibian population declines and extinctions. However, not all infected species are affected equally, and thus Bd is a good example of a multi-host pathogen that must ultimately be studied with a community approach. To test whether the common midwife toad Alytes obstetricans is a reservoir and possible amplifier of infection of other species, we used experimental approaches in captive and wild populations to determine the effect of common midwife toad larvae on infection of other amphibian species found in the Peñalara Massif, Spain. We observed that the most widely and heavily infected species, the common midwife toad, may be amplifying the infection loads in other species, all of which have different degrees of susceptibility to Bd infection. Our results have important implications for performing mitigation actions focused on potential 'amplifier' hosts and for better understanding the mechanisms of Bd transmission. PMID:26865231

  4. Batrachochytrium dendrobatidis not found in rainforest frogs along an altitudinal gradient of Papua New Guinea

    Czech Academy of Sciences Publication Activity Database

    Dahl, C.; Kiatik, I.; Baisen, I.; Bronikowski, E.; Fleischer, R. C.; Rotzel, N. C.; Lock, J.; Novotný, Vojtěch; Narayan, E.; Hero, J.-M.

    2012-01-01

    Roč. 22, č. 3 (2012), s. 183-186. ISSN 0268-0130 Institutional support: RVO:60077344 Keywords : altitude * amphibians * Batrachochytrium dendrobatidis Subject RIV: EH - Ecology, Behaviour Impact factor: 1.081, year: 2012

  5. Patterns of Batrachochytrium dendrobatidis transmission between tadpoles in a high-elevation rainforest stream in tropical Australia.

    Science.gov (United States)

    Hagman, Mattias; Alford, Ross A

    2015-08-20

    The highly virulent fungal pathogen Batrachochytrium dendrobatidis (Bd) poses a global threat to amphibian biodiversity. Streams and other water bodies are central habitats in the ecology of the disease, particularly in rainforests where they may transport and transmit the pathogen and harbor infected tadpoles that serve as reservoir hosts. We conducted an experiment using larval green-eyed tree frogs Litoria serrata in semi-natural streamside channels to test the hypotheses that (1) the fungus can be transmitted downstream in stream habitats and (2) infection affects tadpole growth and mouthpart loss. Our results showed that transmission can occur downstream in flowing water with no contact between individuals, that newly infected tadpoles suffered increased mouthpart loss in comparison with controls that were never infected and that infected tadpoles grew at reduced rates. Although recently infected tadpoles showed substantial loss of mouthparts, individuals with longstanding infections did not, suggesting that mouthparts may re-grow following initial loss. Our study suggests that any management efforts that can reduce the prevalence of infections in tadpoles may be particularly effective if applied in headwater areas, as their effects are likely to be felt downstream. PMID:26290506

  6. Antibacterial therapeutics for the treatment of chytrid infection in amphibians: Columbus's egg?

    OpenAIRE

    Muijsers Mariska; Martel An; Van Rooij Pascale; Baert Kris; Vercauteren Griet; Ducatelle Richard; De Backer Patrick; Vercammen Francis; Haesebrouck Freddy; Pasmans Frank

    2012-01-01

    Abstract Background The establishment of safe and effective protocols to treat chytridiomycosis in amphibians is urgently required. In this study, the usefulness of antibacterial agents to clear chytridiomycosis from infected amphibians was evaluated. Results Florfenicol, sulfamethoxazole, sulfadiazine and the combination of trimethoprim and sulfonamides were active in vitro against cultures of five Batrachochytrium dendrobatidis strains containing sporangia and zoospores, with minimum inhibi...

  7. Hydrological Regimes, Pond Morphology, and Habitat Use: Predicting the Impact of an Emerging Aquatic Pathogen

    OpenAIRE

    Cheryl J Briggs

    2006-01-01

    Declines in amphibian populations have been reported throughout the world in recent years. Chytridiomycosis, a disease of amphibians caused by the chytrid fungus, Batrachochytrium dendrobatidis, is one of a number of factors that have been shown to contribute to these population declines. B. dendrobatidis is associated with rapid population declines and local extinctions of populations of mountain yellow-legged frog, Rana muscosa, in some areas of the California Sierra Nevada mountains, howev...

  8. Seasonal Ecology and Behavior of an Endangered Rainforest Frog (Litoria rheocola) Threatened by Disease

    OpenAIRE

    Elizabeth A Roznik; Ross A. Alford

    2015-01-01

    One of the most devastating wildlife diseases ever recorded is chytridiomycosis, a recently emerged amphibian disease that is caused by the chytrid fungus Batrachochytrium dendrobatidis. Understanding, predicting, and managing the impacts of chytridiomycosis on any amphibian species will require detailed information on its ecology and behavior because this pathogen is transmitted by contact with water or other individuals, and pathogen growth rates are thermally sensitive. The common mistfrog...

  9. Emerging infectious disease and the loss of biodiversity in a Neotropical amphibian community

    OpenAIRE

    Lips, Karen R.; Brem, Forrest; Brenes, Roberto; Reeve, John D.; Ross A. Alford; Voyles, Jamie; Carey, Cynthia; Livo, Lauren; Allan P Pessier; Collins, James P.

    2006-01-01

    Pathogens rarely cause extinctions of host species, and there are few examples of a pathogen changing species richness and diversity of an ecological community by causing local extinctions across a wide range of species. We report the link between the rapid appearance of a pathogenic chytrid fungus Batrachochytrium dendrobatidis in an amphibian community at El Copé, Panama, and subsequent mass mortality and loss of amphibian biodiversity across eight families of frogs and salamanders. We desc...

  10. The demography of Atelopus decline: Harlequin frog survival and abundance in central Panama prior to and during a disease outbreak

    OpenAIRE

    Rebecca McCaffery; Richards-Zawacki, Corinne L.; Karen R Lips

    2015-01-01

    Harlequin frogs (Bufonidae: Atelopus) are a species-rich genus of Neotropical toads that have experienced disproportionately severe population declines and extinctions caused by the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd). The genus Atelopus is of high conservation concern, but relatively little is known about the population dynamics and life history of the majority of species. We examined the demography of one population of Atelopus zeteki and two populations of A. variu...

  11. Tremella with Edible Fungus

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    (Meiwei Shuang’er)Remove the tremella and edible fungus roots, clean and drain. Slice green peppers and carrots.Heat some oil in a wok, add tremella, edible fungus, green peppers and carrots, and clear stock, salt and sugar. Simmer for two minutes. Add MSG and pepper, remove to a plate, and serve.Features: Attractively black and white.Taste: Crisp and savory.

  12. Survey of helminths, ectoparasites, and chytrid fungus of an introduced population of cane toads, Rhinella marina (Anura: Bufonidae), from Grenada

    Science.gov (United States)

    Drake, Michael C.; Zieger, Ulrike; Groszkowski, Andrew; Gallardo, Bruce; Sages, Patti; Reavis, Roslyn; Faircloth, Leslie; Jacobson, Krystin; Lonce, Nicholas; Pinckney, Rhonda D.; Cole, Rebecca Ann

    2014-01-01

    One hundred specimens of Rhinella marina, (Anura: Bufonidae) collected in St. George's parish, Grenada, from September 2010 to August 2011, were examined for the presence of ectoparasites and helminths. Ninety-five (95%) toads were parasitized by one or more parasite species. Nine species of parasites were found: 1 digenean, 2 acanthocephalans, 4 nematodes, 1 arthropod and 1 pentastome. The endoparasites represented 98.9% of the total number of parasite specimens collected. Grenada represents a new locality record for Mesocoelium monas, Raillietiella frenatus, Pseudoacanthacephalus sp., Aplectana sp., Physocephalus sp., Acanthacephala cystacanth and Physalopteridae larvae. The digenean M. monas occurred with the highest prevalence of 82%, contrasting many studies of R. marina where nematodes dominate the parasite infracommunity. Female toads were found to have a significantly higher prevalence of Amblyomma dissimile than male toads. Only two parasites exhibited a significant difference between wet and dry season with Parapharyngodon grenadensis prevalence highest in the wet season and A. dissimile prevalence highest during the dry season. Additionally, A. dissimile was significantly more abundant during the dry season.

  13. Baseline Population Inventory of Amphibians on the Mountain Longleaf National Wildlife Refuge and Screening for the Amphibian Disease Batrachochytrium dendrobatidis

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — From July of 2012 to June of 2013, we conducted baseline inventories for amphibians and sampled for the disease Batrachochytrium dendrobatidis on the Mountain...

  14. CITIZEN SCIENTISTS MONITOR A DEADLY FUNGUS THREATENING AMPHIBIAN COMMUNITIES IN NORTHERN COASTAL CALIFORNIA, USA.

    Science.gov (United States)

    Group, Ecoclub Amphibian; Pope, Karen L; Wengert, Greta M; Foley, Janet E; Ashton, Donald T; Botzler, Richard G

    2016-07-01

    Ecoclub youth and supervising family members conducted citizen science to assess regional prevalence and distribution of Batrachochytrium dendrobatidis (Bd) among amphibians at Humboldt Bay National Wildlife Refuge (Refuge) and Redwood National and State Parks (Parks), Humboldt County, California, US, May 2013 through December 2014. Using quantitative real-time PCR, 26 (17%) of 155 samples were positive for Bd. Positive samples occurred in four frog and toad species: foothill yellow-legged frog ( Rana boylii ), northern red-legged frog ( Rana aurora ), Pacific chorus frog ( Pseudacris regilla ), and western toad (Anaxyrus [Bufo] boreas); no salamanders or anuran larvae were positive. Except for R. aurora , all infected anurans were first-time species reports for coastal northern California. At the Refuge, significantly fewer (6/71) postmetamorphic amphibians were positive compared to the Parks (20/69; P=0.0018). We assessed the association of being PCR-positive for Bd, season of sampling, and age of sampler (child, teen, or adult). The full model with season, species, and sampler age had the greatest support. Frogs tested in winter or spring were more likely to be positive than those tested in summer or fall; foothill yellow-legged frogs, northern red-legged frogs, and western toads were more likely to be positive than were Pacific chorus frogs; and the probability of being positive nearly doubled when a child (≤12 yr old) collected the sample compared to a teen or adult. Our results support other chytrid studies that found amphibians are more susceptible to Bd when temperatures are cool and that species differ in their susceptibility. The Ecoclub's findings provide new information important to conservation of northern California's coastal amphibians and demonstrate the value of involving children in citizen science. PMID:27195681

  15. ITS1 copy number varies among Batrachochytrium dendrobatidis strains: implications for qPCR estimates of infection intensity from field-collected amphibian skin swabs.

    Directory of Open Access Journals (Sweden)

    Ana V Longo

    Full Text Available Genomic studies of the amphibian-killing fungus (Batrachochytrium dendrobatidis, [Bd] identified three highly divergent genetic lineages, only one of which has a global distribution. Bd strains within these linages show variable genomic content due to differential loss of heterozygosity and recombination. The current quantitative polymerase chain reaction (qPCR protocol to detect the fungus from amphibian skin swabs targets the intergenic transcribed spacer 1 (ITS1 region using a TaqMan fluorescent probe specific to Bd. We investigated the consequences of genomic differences in the quantification of ITS1 from eight distinct Bd strains, including representatives from North America, South America, the Caribbean, and Australia. To test for potential differences in amplification, we compared qPCR standards made from Bd zoospore counts for each strain, and showed that they differ significantly in amplification rates. To test potential mechanisms leading to strain differences in qPCR reaction parameters (slope and y-intercept, we: a compared standard curves from the same strains made from extracted Bd genomic DNA in equimolar solutions, b quantified the number of ITS1 copies per zoospore using a standard curve made from PCR-amplicons of the ITS1 region, and c cloned and sequenced PCR-amplified ITS1 regions from these same strains to verify the presence of the probe site in all haplotypes. We found high strain variability in ITS1 copy number, ranging from 10 to 144 copies per single zoospore. Our results indicate that genome size might explain strain differences in ITS1 copy number, but not ITS1 sequence variation because the probe-binding site and primers were conserved across all haplotypes. For standards constructed from uncharacterized Bd strains, we recommend the use of single ITS1 PCR-amplicons as the absolute standard in conjunction with current quantitative assays to inform on copy number variation and provide universal estimates of pathogen

  16. Batrachochytrium dendrobatidis in amphibians from the Po River Delta, Northern Italy

    OpenAIRE

    Gentile Francesco Ficetola; Alice Valentini; Claude Miaud; Andrea Noferini; Stefano Mazzotti; Tony Dejean

    2011-01-01

    Batrachochytrium dendrobatidis is a pathogen infecting amphibians at the global scale and causing their decline, but knowledge of the distribution of this pathogen is far from complete. We sampled amphibians from three species (Hyla intermedia, Rana dalmatina and Pelophylax synklepton esculentus) to evaluate whether B. dendrobatidis infects amphibians in the Po River Delta Natural Park, Northern Italy. We detected the pathogen in one population of P. sk. esculentus (prevalence: 0.33). These f...

  17. Diagnosis of Aeromonas hydrophila, Mycobacterium species, and Batrachochytrium dendrobatidis in an African Clawed Frog (Xenopus laevis)

    OpenAIRE

    Hill, William A; Newman, Shelley J; Craig, Linden; Carter, Christopher; Czarra, Jane; Brown, J Paige

    2010-01-01

    Here we describe diagnosis of concurrent infection with Aeromonas hydrophila, Mycobacterium spp., and Batrachochytrium dendrobatidis in a wild female Xenopus laevis captured in Chile and transported to the United States. After approximately 130 d in the laboratory, the frog was presented for dysecdysis and obtundation. After euthanasia, tissues were submitted for histopathologic evaluation and PCR analysis for B. dendrobatidis and Ranavirus. Clinically significant gross lesions included cutan...

  18. Species-Specific Chitin-Binding Module 18 Expansion in the Amphibian Pathogen Batrachochytrium dendrobatidis

    OpenAIRE

    Abramyan, John; Stajich, Jason E.

    2012-01-01

    ABSTRACT Batrachochytrium dendrobatidis is the causative agent of chytridiomycosis, which is considered one of the driving forces behind the worldwide decline in populations of amphibians. As a member of the phylum Chytridiomycota, B. dendrobatidis has diverged significantly to emerge as the only pathogen of adult vertebrates. Such shifts in lifestyle are generally accompanied by various degrees of genomic modifications, yet neither its mode of pathogenicity nor any factors associated with it...

  19. Coincident mass extirpation of neotropical amphibians with the emergence of the infectious fungal pathogen Batrachochytrium dendrobatidis

    OpenAIRE

    Cheng, Tina L.; Rovito, Sean M.; Wake, David B; Vance T Vredenburg

    2011-01-01

    Amphibians highlight the global biodiversity crisis because ∼40% of all amphibian species are currently in decline. Species have disappeared even in protected habitats (e.g., the enigmatic extinction of the golden toad, Bufo periglenes, from Costa Rica). The emergence of a fungal pathogen, Batrachochytrium dendrobatidis (Bd), has been implicated in a number of declines that have occurred in the last decade, but few studies have been able to test retroactively whether Bd emergence was linked t...

  20. Expression Profiling the Temperature-Dependent Amphibian Response to Infection by Batrachochytrium dendrobatidis

    OpenAIRE

    Ribas, Laia; Li, Ming-Shi; Doddington, Benjamin J.; Robert, Jacques; Seidel, Judith A.; Kroll, J. Simon; Zimmerman, Lyle B.; Grassly, Nicholas C.; Trenton W J Garner; Fisher, Matthew C

    2009-01-01

    Amphibians are experiencing a panzootic of unprecedented proportions caused by the emergence of Batrachochytrium dendrobatidis (Bd). However, all species are not equally at risk of infection, and risk is further modified by environmental variables, specifically temperature. In order to understand how, and when, hosts mount a response to Bd we analysed infection dynamics and patterns of gene expression in the model amphibian species Silurana (Xenopus) tropicalis. Mathematical modelling of infe...

  1. Reduced Itraconazole Concentration and Durations Are Successful in Treating Batrachochytrium dendrobatidis Infection in Amphibians

    OpenAIRE

    Laura A Brannelly

    2014-01-01

    Amphibians are experiencing the greatest decline of any vertebrate class and a leading cause of these declines is a fungal pathogen, Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis. Captive assurance colonies are important worldwide for threatened amphibian species and may be the only lifeline for those in critical threat of extinction. Maintaining disease free colonies is a priority of captive managers, yet safe and effective treatments for all species and acro...

  2. Germ Tube Mediated Invasion of Batrachochytrium dendrobatidis in Amphibian Skin Is Host Dependent

    OpenAIRE

    Van Rooij, Pascale; Martel, An; D'Herde, Katharina; Brutyn, Melanie; Croubels, Siska; Ducatelle, Richard; Haesebrouck, Freddy; Pasmans, Frank

    2012-01-01

    Batrachochytrium dendrobatidis (Bd) is the causative agent of chytridiomycosis, a fungal skin disease in amphibians and driver of worldwide amphibian declines. We focussed on the early stages of infection by Bd in 3 amphibian species with a differential susceptibility to chytridiomycosis. Skin explants of Alytes muletensis, Litoria caerulea and Xenopus leavis were exposed to Bd in an Ussing chamber for 3 to 5 days. Early interactions of Bd with amphibian skin were observed using light microsc...

  3. White-Nose Syndrome fungus introduced from Europe to North America.

    Science.gov (United States)

    Leopardi, Stefania; Blake, Damer; Puechmaille, Sébastien J

    2015-03-16

    The investigation of factors underlying the emergence of fungal diseases in wildlife has gained significance as a consequence of drastic declines in amphibians, where the fungus Batrachochytrium dendrobatidis has caused the greatest disease-driven loss of biodiversity ever documented [1]. Identification of the causative agent and its origin (native versus introduced) is a crucial step in understanding and controlling a disease [2]. Whereas genetic studies on the origin of B. dendrobatidis have illuminated the mechanisms behind the global emergence of amphibian chytridiomycosis [3], the origin of another recently-emerged fungal disease, White-Nose Syndrome (WNS) and its causative agent, Pseudogymnoascus destructans, remains unresolved [2,4]. WNS is decimating multiple North American bat species with an estimated death toll reaching 5-6 million. Here, we present the first informative molecular comparison between isolates from North America and Europe and provide strong evidence for the long-term presence of the fungus in Europe and a recent introduction into North America. Our results further demonstrate great genetic similarity between the North American and some European fungal populations, indicating the likely source population for this introduction from Europe. PMID:25784035

  4. Batrachochytrium dendrobatidis in amphibians from the Po River Delta, Northern Italy

    Directory of Open Access Journals (Sweden)

    Gentile Francesco Ficetola

    2011-12-01

    Full Text Available Batrachochytrium dendrobatidis is a pathogen infecting amphibians at the global scale and causing their decline, but knowledge of the distribution of this pathogen is far from complete. We sampled amphibians from three species (Hyla intermedia, Rana dalmatina and Pelophylax synklepton esculentus to evaluate whether B. dendrobatidis infects amphibians in the Po River Delta Natural Park, Northern Italy. We detected the pathogen in one population of P. sk. esculentus (prevalence: 0.33. These findings expand the known distribution of B. dendrobatidis in Italy and add further concern to the conservation of amphibians in this area.

  5. Estudio de quitridiomicosis por Batrachochytrium dendrobatidis en anfibios anuros del Litoral, Cuyo y Patagonia Argentina

    OpenAIRE

    Ghirardi, Romina

    2012-01-01

    La quitridiomicosis es una enfermedad emergente que en los últimos años ha sido vinculada a la muerte masiva de los anfibios. Esta enfermedad es causada por el hongo acuático zoospórico Batrachochytrium dendrobatidis -Bd- (Orden Rhyzophydiales). La infección de los anfibios comienza cuando las zoosporas móviles contactan un animal susceptible y penetran en su piel. Las alteraciones producidas por esta infección interfieren con varias funciones epiteliales de los anfibios como la circulación y...

  6. Amphibian Symbiotic Bacteria Do Not Show a Universal Ability To Inhibit Growth of the Global Panzootic Lineage of Batrachochytrium dendrobatidis

    OpenAIRE

    Antwis, Rachael E.; Preziosi, Richard F.; Harrison, Xavier A.; Trenton W J Garner

    2015-01-01

    Microbiomes associated with multicellular organisms influence the disease susceptibility of hosts. The potential exists for such bacteria to protect wildlife from infectious diseases, particularly in the case of the globally distributed and highly virulent fungal pathogen Batrachochytrium dendrobatidis of the global panzootic lineage (B. dendrobatidis GPL), responsible for mass extinctions and population declines of amphibians. B. dendrobatidis GPL exhibits wide genotypic and virulence variat...

  7. Experimental evolution alters the rate and temporal pattern of population growth in Batrachochytrium dendrobatidis, a lethal fungal pathogen of amphibians

    OpenAIRE

    Voyles, Jamie; Johnson, Leah R.; Briggs, Cheryl J.; Cashins, Scott D.; Ross A. Alford; Berger, Lee; Lee F Skerratt; Speare, Rick; Rosenblum, Erica Bree

    2014-01-01

    Virulence of infectious pathogens can be unstable and evolve rapidly depending on the evolutionary dynamics of the organism. Experimental evolution can be used to characterize pathogen evolution, often with the underlying objective of understanding evolution of virulence. We used experimental evolution techniques (serial transfer experiments) to investigate differential growth and virulence of Batrachochytrium dendrobatidis (Bd), a fungal pathogen that causes amphibian chytridiomycosis. We te...

  8. American Bullfrogs (Lithobates catesbeianus) Resist Infection by Multiple Isolates of Batrachochytrium dendrobatidis, Including One Implicated in Wild Mass Mortality

    OpenAIRE

    Eskew, EA; Worth, SJ; Foley, JE; Todd, BD

    2015-01-01

    © 2015, International Association for Ecology and Health. The emerging amphibian disease chytridiomycosis varies in severity depending on host species. Within species, disease susceptibility can also be influenced by pathogen variation and environmental factors. Here, we report on experimental exposures of American bullfrogs (Lithobates catesbeianus) to three different isolates of Batrachochytrium dendrobatidis (Bd), including one implicated in causing mass mortality of wild American bullfrog...

  9. Experimental evidence for a cost of resistance to the fungal pathogen, Batrachochytrium dendrobatidis, for the palmate newt, Lissotriton helveticus

    OpenAIRE

    Cheatsazan, Hamed; de Almedia, Ana P Lugon Gavinho; Russell, Andrew F.; Bonneaud, Camille

    2013-01-01

    Background Batrachochytrium dendrobatidis (Bd), the causative agent of chytridiomycosis, is decimating amphibians worldwide. Unsurprisingly, the majority of studies have therefore concentrated on documenting morbidity and mortality of susceptible species and projecting population consequences as a consequence of this emerging infectious disease. Currently, there is a paucity of studies investigating the sub-lethal costs of Bd in apparently asymptomatic species, particularly in controlled expe...

  10. Asian strain of Batrachochytrium dendrobatidis is widespread in the Western Ghats, India.

    Science.gov (United States)

    Molur, Sanjay; Krutha, Keerthi; Paingankar, Mandar S; Dahanukar, Neelesh

    2015-01-15

    We investigated the distribution of Batrachochytrium dendrobatidis (Bd) fungal infections in amphibians of the Western Ghats mountain range in India, based on data from 497 samples. Eight individuals were positive, with genomic equivalents ranging from 2 to 785 zoospores. A single widespread Bd strain identical to the haplotype endemic to Asia was isolated. Our findings suggest that chytridiomycosis is widespread among the endemic and threatened amphibians of the entire stretch of the Western Ghats. An ecological niche-based prediction model based on all Bd-positive reports from the Western Ghats to date suggested a higher probability of infection in the central Western Ghats of Karnataka and northern Kerala states, which host a rich diversity of endemic and threatened amphibians. PMID:25590776

  11. Detection of the emerging amphibian pathogens Batrachochytrium dendrobatidis and ranavirus in Russia

    Science.gov (United States)

    Reshetnikov, Andrey N.; Chestnut, Tara E.; Brunner, Jesse L.; Charles, Kaylene M.; Nebergall, Emily E.; Olson, Deanna H.

    2014-01-01

    In a population of the European common toad Bufo bufo from a rural pond in the region of Lake Glubokoe Regional Reserve in Moscow province, Russia, unexplained mass mortality events involving larvae and metamorphs have been observed over a monitoring period of >20 yr. We tested toads from this and a nearby site for the emerging amphibian pathogens Batrachochytrium dendrobatidis (Bd) and ranavirus (Rv). Both pathogens were detected, and at the rural pond site, with the above-noted losses and decline in toad breeding success, 40% of B. bufo metamorphs were Bd positive, 46% were Rv positive and 20% were co-infected with both pathogens. Toad metamorphs from a neighbouring water body were also Bd and Rv positive (25 and 55%, respectively). This is the first confirmation of these pathogens in Russia. Questions remain as to the origins of these pathogens in Russia and their roles in documented mass mortality events.

  12. Antibacterial therapeutics for the treatment of chytrid infection in amphibians: Columbus’s egg?

    Directory of Open Access Journals (Sweden)

    Muijsers Mariska

    2012-09-01

    Full Text Available Abstract Background The establishment of safe and effective protocols to treat chytridiomycosis in amphibians is urgently required. In this study, the usefulness of antibacterial agents to clear chytridiomycosis from infected amphibians was evaluated. Results Florfenicol, sulfamethoxazole, sulfadiazine and the combination of trimethoprim and sulfonamides were active in vitro against cultures of five Batrachochytrium dendrobatidis strains containing sporangia and zoospores, with minimum inhibitory concentrations (MIC of 0.5-1.0 μg/ml for florfenicol and 8.0 μg/ml for the sulfonamides. Trimethoprim was not capable of inhibiting growth but, combined with sulfonamides, reduced the time to visible growth inhibition by the sulfonamides. Growth inhibition of B. dendrobatidis was not observed after exposure to clindamycin, doxycycline, enrofloxacin, paromomycin, polymyxin E and tylosin. Cultures of sporangia and zoospores of B. dendrobatidis strains JEL423 and IA042 were killed completely after 14 days of exposure to 100 μg/ml florfenicol or 16 μg/ml trimethoprim combined with 80 μg/ml sulfadiazine. These concentrations were, however, not capable of efficiently killing zoospores within 4 days after exposure as assessed using flow cytometry. Florfenicol concentrations remained stable in a bathing solution during a ten day period. Exposure of Discoglossus scovazzi tadpoles for ten days to 100 μg/ml but not to 10 μg florfenicol /ml water resulted in toxicity. In an in vivo trial, post metamorphic Alytes muletensis, experimentally inoculated with B. dendrobatidis, were treated topically with a solution containing 10 μg/ml of florfenicol during 14 days. Although a significant reduction of the B. dendrobatidis load was obtained, none of the treated animals cleared the infection. Conclusions We thus conclude that, despite marked anti B. dendrobatidis activity in vitro, the florfenicol treatment used is not capable of eliminating B

  13. Surviving Chytridiomycosis: Differential Anti-Batrachochytrium dendrobatidis Activity in Bacterial Isolates from Three Lowland Species of Atelopus

    OpenAIRE

    Flechas, Sandra V.; Sarmiento, Carolina; Martha E Cárdenas; Edgar M Medina; Restrepo, Silvia; Amézquita, Adolfo

    2012-01-01

    In the Neotropics, almost every species of the stream-dwelling harlequin toads (genus Atelopus) have experienced catastrophic declines. The persistence of lowland species of Atelopus could be explained by the lower growth rate of Batrachochytrium dendrobatidis (Bd) at temperatures above 25°C. We tested the complementary hypothesis that the toads' skin bacterial microbiota acts as a protective barrier against the pathogen, perhaps delaying or impeding the symptomatic phase of chytridiomycosis....

  14. Widespread Occurrence of Batrachochytrium dendrobatidis in Contemporary and Historical Samples of the Endangered Bombina pachypus along the Italian Peninsula

    OpenAIRE

    Canestrelli, Daniele; Zampiglia, Mauro; Nascetti, Giuseppe

    2013-01-01

    Batrachochytrium dendrobatidis is considered a main driver of the worldwide declines and extinctions of amphibian populations. Nonetheless, fundamental questions about its epidemiology, including whether it acts mainly as a “lone killer” or in conjunction with other factors, remain largely open. In this paper we analysed contemporary and historical samples of the endangered Apennine yellow-bellied toad (Bombina pachypus) along the Italian peninsula, in order to assess the presence of the path...

  15. Persistence of the emerging pathogen Batrachochytrium dendrobatidis outside the amphibian host greatly increases the probability of host extinction

    OpenAIRE

    Mitchell, Kate M.; Thomas S Churcher; Trenton W J Garner; Fisher, Matthew C

    2007-01-01

    Pathogens do not normally drive their hosts to extinction; however, Batrachochytrium dendrobatidis, which causes amphibian chytridiomycosis, has been able to do so. Theory predicts that extinction can be caused by long-lived or saprobic free-living stages. The hypothesis that such a stage occurs in B. dendrobatidis is supported by the recent discovery of an apparently encysted form of the pathogen. To investigate the effect of a free-living stage of B. dendrobatidis on host population dynamic...

  16. Elevated Corticosterone Levels and Changes in Amphibian Behavior Are Associated with Batrachochytrium dendrobatidis (Bd) Infection and Bd Lineage

    OpenAIRE

    Gabor, Caitlin R.; Fisher, Matthew C; Bosch, Jaime

    2015-01-01

    Few studies have examined the role hormones play in mediating clinical changes associated with infection by the parasite Batrachochytrium dendrobatidis (Bd). Glucocorticoid (GC) hormones such as corticosteroids (CORT) regulate homeostasis and likely play a key role in response to infection in amphibians. We explore the relationship between CORT release rates and Bd infection in tadpoles of the common midwife toad, Alytes obstetricians, using a non-invasive water-borne hormone collection metho...

  17. Parasite fitness traits under environmental variation: disentangling the roles of a chytrid's immediate host and external environment.

    Science.gov (United States)

    Van den Wyngaert, Silke; Vanholsbeeck, Olivier; Spaak, Piet; Ibelings, Bas W

    2014-10-01

    Parasite environments are heterogeneous at different levels. The first level of variability is the host itself. The second level represents the external environment for the hosts, to which parasites may be exposed during part of their life cycle. Both levels are expected to affect parasite fitness traits. We disentangle the main and interaction effects of variation in the immediate host environment, here the diatom Asterionella formosa (variables host cell volume and host condition through herbicide pre-exposure) and variation in the external environment (variables host density and acute herbicide exposure) on three fitness traits (infection success, development time and reproductive output) of a chytrid parasite. Herbicide exposure only decreased infection success in a low host density environment. This result reinforces the hypothesis that chytrid zoospores use photosynthesis-dependent chemical cues to locate its host. At high host densities, chemotaxis becomes less relevant due to increasing chance contact rates between host and parasite, thereby following the mass-action principle in epidemiology. Theoretical support for this finding is provided by an agent-based simulation model. The immediate host environment (cell volume) substantially affected parasite reproductive output and also interacted with the external herbicide exposed environment. On the contrary, changes in the immediate host environment through herbicide pre-exposure did not increase infection success, though it had subtle effects on zoospore development time and reproductive output. This study shows that both immediate host and external environment as well as their interaction have significant effects on parasite fitness. Disentangling these effects improves our understanding of the processes underlying parasite spread and disease dynamics. PMID:24863129

  18. In vitro sensitivity of the amphibian pathogen Batrachochytrium dendrobatidis to antifungal therapeutics.

    Science.gov (United States)

    Woodward, A; Berger, L; Skerratt, L F

    2014-10-01

    Chytridiomycosis, a skin disease caused by Batrachochytrium dendrobatidis, has caused amphibian declines worldwide. Amphibians can be treated by percutaneous application of antimicrobials, but knowledge of in vitro susceptibility is lacking. Using a modified broth microdilution method, we describe the in vitro sensitivity of two Australian isolates of B. dendrobatidis to six antimicrobial agents. Growth inhibition was observed, by measurement of optical density, with all agents. Minimum inhibitory concentrations (µg/ml; isolate 1/2) were - voriconazole 0.016/0.008; itraconazole 0.032/0.016; terbinafine 0.063/0.063; fluconazole 0.31/0.31; chloramphenicol 12.5/12.5; amphotericin B 12.5/6.25. Killing effects on zoospores were assessed by observing motility. Amphotericin B and terbinafine killed zoospores within 5 and 30 min depending on concentration, but other antimicrobials were not effective at the highest concentrations tested (100 µg/ml). This knowledge will help in drug selection and treatment optimization. As terbinafine was potent and has rapid effects, study of its pharmacokinetics, safety and efficacy is recommended. PMID:25241392

  19. Predicting the potential distribution of the amphibian pathogen Batrachochytrium dendrobatidis in East and Southeast Asia.

    Science.gov (United States)

    Moriguchi, Sachiko; Tominaga, Atsushi; Irwin, Kelly J; Freake, Michael J; Suzuki, Kazutaka; Goka, Koichi

    2015-04-01

    Batrachochytrium dendrobatidis (Bd) is the pathogen responsible for chytridiomycosis, a disease that is associated with a worldwide amphibian population decline. In this study, we predicted the potential distribution of Bd in East and Southeast Asia based on limited occurrence data. Our goal was to design an effective survey area where efforts to detect the pathogen can be focused. We generated ecological niche models using the maximum-entropy approach, with alleviation of multicollinearity and spatial autocorrelation. We applied eigenvector-based spatial filters as independent variables, in addition to environmental variables, to resolve spatial autocorrelation, and compared the model's accuracy and the degree of spatial autocorrelation with those of a model estimated using only environmental variables. We were able to identify areas of high suitability for Bd with accuracy. Among the environmental variables, factors related to temperature and precipitation were more effective in predicting the potential distribution of Bd than factors related to land use and cover type. Our study successfully predicted the potential distribution of Bd in East and Southeast Asia. This information should now be used to prioritize survey areas and generate a surveillance program to detect the pathogen. PMID:25850395

  20. Differences in sensitivity to the fungal pathogen Batrachochytrium dendrobatidis among amphibian populations.

    Science.gov (United States)

    Bradley, Paul W; Gervasi, Stephanie S; Hua, Jessica; Cothran, Rickey D; Relyea, Rick A; Olson, Deanna H; Blaustein, Andrew R

    2015-10-01

    Contributing to the worldwide biodiversity crisis are emerging infectious diseases, which can lead to extirpations and extinctions of hosts. For example, the infectious fungal pathogen Batrachochytrium dendrobatidis (Bd) is associated with worldwide amphibian population declines and extinctions. Sensitivity to Bd varies with species, season, and life stage. However, there is little information on whether sensitivity to Bd differs among populations, which is essential for understanding Bd-infection dynamics and for formulating conservation strategies. We experimentally investigated intraspecific differences in host sensitivity to Bd across 10 populations of wood frogs (Lithobates sylvaticus) raised from eggs to metamorphosis. We exposed the post-metamorphic wood frogs to Bd and monitored survival for 30 days under controlled laboratory conditions. Populations differed in overall survival and mortality rate. Infection load also differed among populations but was not correlated with population differences in risk of mortality. Such population-level variation in sensitivity to Bd may result in reservoir populations that may be a source for the transmission of Bd to other sensitive populations or species. Alternatively, remnant populations that are less sensitive to Bd could serve as sources for recolonization after epidemic events. PMID:26219571

  1. Carotenoids and amphibians: effects on life history and susceptibility to the infectious pathogen, Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Cothran, Rickey D; Gervasi, Stephanie S; Murray, Cindy; French, Beverly J; Bradley, Paul W; Urbina, Jenny; Blaustein, Andrew R; Relyea, Rick A

    2015-01-01

    Carotenoids are considered beneficial nutrients because they provide increased immune capacity. Although carotenoid research has been conducted in many vertebrates, little research has been done in amphibians, a group that is experiencing global population declines from numerous causes, including disease. We raised two amphibian species through metamorphosis on three carotenoid diets to quantify the effects on life-history traits and post-metamorphic susceptibility to a fungal pathogen (Batrachochytrium dendrobatidis; Bd). Increased carotenoids had no effect on survival to metamorphosis in gray treefrogs (Hyla versicolor) but caused lower survival to metamorphosis in wood frogs [Lithobates sylvaticus (Rana sylvatica)]. Increased carotenoids caused both species to experience slower development and growth. When exposed to Bd after metamorphosis, wood frogs experienced high mortality, and the carotenoid diets had no mitigating effects. Gray treefrogs were less susceptible to Bd, which prevented an assessment of whether carotenoids could mitigate the effects of Bd. Moreover, carotenoids had no effect on pathogen load. As one of only a few studies examining the effects of carotenoids on amphibians and the first to examine potential interactions with Bd, our results suggest that carotenoids do not always serve amphibians in the many positive ways that have become the paradigm in other vertebrates. PMID:27293690

  2. Filling a gap in the distribution of Batrachochytrium dendrobatidis: evidence in amphibians from northern China.

    Science.gov (United States)

    Zhu, Wei; Fan, Liqing; Soto-Azat, Claudio; Yan, Shaofei; Gao, Xu; Liu, Xuan; Wang, Supen; Liu, Conghui; Yang, Xuejiao; Li, Yiming

    2016-03-30

    Chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd) has been recognized as a major driver of amphibian declines worldwide. Central and northern Asia remain as the greatest gap in the knowledge of the global distribution of Bd. In China, Bd has recently been recorded from south and central regions, but areas in the north remain poorly surveyed. In addition, a recent increase in amphibian farming and trade has put this region at high risk for Bd introduction. To investigate this, we collected a total of 1284 non-invasive skin swabs from wild and captive anurans and caudates, including free-ranging, farmed, ornamental, and museum-preserved amphibians. Bd was detected at low prevalence (1.1%, 12 of 1073) in live wild amphibians, representing the first report of Bd infecting anurans from remote areas of northwestern China. We were unable to obtain evidence of the historical presence of Bd from museum amphibians (n = 72). Alarmingly, Bd was not detected in wild amphibians from the provinces of northeastern China (>700 individuals tested), but was widely present (15.1%, 21 of 139) in amphibians traded in this region. We suggest that urgent implementation of measures is required to reduce the possibility of further spread or inadvertent introduction of Bd to China. It is unknown whether Bd in northern China belongs to endemic and/or exotic genotypes, and this should be the focus of future research. PMID:27025313

  3. Quantitative PCR detection of Batrachochytrium dendrobatidis DNA from sediments and water

    Science.gov (United States)

    Kirshtein, J.D.; Anderson, C.W.; Wood, J.S.; Longcore, J.E.; Voytek, M.A.

    2007-01-01

    The fungal pathogen Batrachochytrium dendrobatidis (Bd) causes chytridiomycosis, a disease implicated in amphibian declines on 5 continents. Polymerase chain reaction (PCR) primer sets exist with which amphibians can be tested for this disease, and advances in sampling techniques allow non-invasive testing of animals. We developed filtering and PCR based quantitative methods by modifying existing PCR assays to detect Bd DNA in water and sediments, without the need for testing amphibians; we tested the methods at 4 field sites. The SYBR based assay using Boyle primers (SYBR/Boyle assay) and the Taqman based assay using Wood primers performed similarly with samples generated in the laboratory (Bd spiked filters), but the SYBR/Boyle assay detected Bd DNA in more field samples. We detected Bd DNA in water from 3 of 4 sites tested, including one pond historically negative for chytridiomycosis. Zoospore equivalents in sampled water ranged from 19 to 454 l-1 (nominal detection limit is 10 DNA copies, or about 0.06 zoospore). We did not detect DNA of Bd from sediments collected at any sites. Our filtering and amplification methods provide a new tool to investigate critical aspects of Bd in the environment. ?? Inter-Research 2007.

  4. Delayed metamorphosis of amphibian larvae facilitates Batrachochytrium dendrobatidis transmission and persistence.

    Science.gov (United States)

    Medina, Daniel; Garner, Trenton W J; Carrascal, Luis María; Bosch, Jaime

    2015-12-01

    Highly virulent pathogens that cause host population declines confront the risk of fade-out, but if pathogen transmission dynamics are age-structured, pathogens can persist. Among other features of amphibian biology, variable larval developmental rates generate age-structured larval populations, which in theory can facilitate pathogen persistence. We investigated this possibility empirically in a population of Salamandra salamandra in Spain affected by Batrachochytrium dendrobatidis (Bd) at breeding sites that lacked alternative amphibian hosts. None of the adults presented infection by Bd. However, for the larvae, while environmental heterogeneity was the most important predictor of infection, the effect on infection dynamics was mediated by transmission from overwintered larvae to new larval recruits, which occurred only in permanent larval habitats. We suggest that interannual Bd maintenance in a host population that experiences mass mortality associated with infection can occur without an environmental reservoir or direct involvement of an alternative host in our study system. However the 2 aquatic habitat types that support intraspecific reservoirs, permanent streams and ponds, are not ideal habitats for long-term Bd maintenance, either due to poor transmission probability or low host survival, respectively. While intraspecific pathogen maintenance due to larval plasticity might be possible at our study sites, this transmission pattern is not without significant risk to the pathogen. The availability of alternative hosts nearby does indicate that permanent Bd fade-out is unlikely. PMID:26648101

  5. Social-insect fungus farming

    DEFF Research Database (Denmark)

    Aanen, Duur Kornelis; Boomsma, Jacobus Jan

    2006-01-01

    Which social insects rear their own food? Growing fungi for food has evolved twice in social insects: once in new-world ants about 50 million years ago; and once in old-world termites between 24 and 34 million years ago [1] and [2] . The termites domesticated a single fungal lineage - the extant...... basidiomycete genus Termitomyces - whereas the ants are associated with a larger diversity of fungal lineages (all basidiomycetes). The ants and termites forage for plant material to provision their fungus gardens. Their crops convert this carbon-rich plant material into nitrogen-rich fungal biomass to provide...

  6. [Cutaneous mold fungus granuloma from Ulocladium chartarum].

    Science.gov (United States)

    Altmeyer, P; Schon, K

    1981-01-01

    Cutaneous granulomas due to the mold fungus Ulocladium chartarum (Preuss) are described in a 58 year old woman. This fungus is usually harmless for mammalian. It is thought that a consisting immunosuppression (Brill-Symmer's disease, therapy with corticosteroids) was a priming condition for the infection. The route of infection in this patient described is unknown. PMID:7194869

  7. Batrachochytrium dendrobatidis Shows High Genetic Diversity and Ecological Niche Specificity among Haplotypes in the Maya Mountains of Belize

    OpenAIRE

    Kaiser, Kristine; Pollinger, John

    2012-01-01

    The amphibian pathogen Batrachochytrium dendrobatidis (Bd) has been implicated in amphibian declines around the globe. Although it has been found in most countries in Central America, its presence has never been assessed in Belize. We set out to determine the range, prevalence, and diversity of Bd using quantitative PCR (qPCR) and sequencing of a portion of the 5.8 s and ITS1-2 regions. Swabs were collected from 524 amphibians of at least 26 species in the protected areas of the Maya Mountain...

  8. American Bullfrogs (Lithobates catesbeianus) Resist Infection by Multiple Isolates of Batrachochytrium dendrobatidis, Including One Implicated in Wild Mass Mortality.

    Science.gov (United States)

    Eskew, Evan A; Worth, S Joy; Foley, Janet E; Todd, Brian D

    2015-09-01

    The emerging amphibian disease chytridiomycosis varies in severity depending on host species. Within species, disease susceptibility can also be influenced by pathogen variation and environmental factors. Here, we report on experimental exposures of American bullfrogs (Lithobates catesbeianus) to three different isolates of Batrachochytrium dendrobatidis (Bd), including one implicated in causing mass mortality of wild American bullfrogs. Exposed frogs showed low infection prevalence, relatively low infection load, and lack of clinical disease. Our results suggest that environmental cofactors are likely important contributors to Bd-associated American bullfrog mortality and that this species both resists and tolerates Bd infection. PMID:26065669

  9. Differential efficiency among DNA extraction methods influences detection of the amphibian pathogen Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Bletz, M C; Rebollar, E A; Harris, R N

    2015-02-10

    Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is responsible for massive declines and extinctions of amphibians worldwide. The most common method for detecting Bd is quantitative polymerase chain reaction (qPCR). qPCR is a highly sensitive detection technique, but its ability to determine the presence and accurately quantify the amount of Bd is also contingent on the efficiency of the DNA extraction method used prior to PCR. Using qPCR, we compared the extraction efficiency of 3 different extraction methods commonly used for Bd detection across a range of zoospore quantities: PrepMan Ultra Reagent, Qiagen DNeasy Blood and Tissue Kit, and Mobio PowerSoil DNA Isolation Kit. We show that not all extraction methods led to successful detection of Bd for the low zoospore quantities and that there was variation in the estimated zoospore equivalents among the methods, which demonstrates that these methods have different extraction efficiencies. These results highlight the importance of considering the extraction method when comparing across studies. The Qiagen DNeasy kit had the highest efficiency. We also show that replicated estimates of less than 1 zoospore can result from known zoospore concentrations; therefore, such results should be considered when obtained from field data. Additionally, we discuss the implications of our findings for interpreting previous studies and for conducting future Bd surveys. It is imperative to use the most efficient DNA extraction method in tandem with the highly sensitive qPCR technique in order to accurately diagnose the presence of Bd as well as other pathogens. PMID:25667331

  10. Itraconazole treatment reduces Batrachochytrium dendrobatidis prevalence and increases overwinter field survival in juvenile Cascades frogs.

    Science.gov (United States)

    Hardy, Bennett M; Pope, Karen L; Piovia-Scott, Jonah; Brown, Richard N; Foley, Janet E

    2015-01-15

    The global spread of the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to widespread extirpation of amphibian populations. During an intervention aimed at stabilizing at-risk populations, we treated wild-caught Cascades frogs Rana cascadae with the antifungal drug itraconazole. In fall 2012, we collected 60 recently metamorphosed R. cascadae from 1 of the 11 remnant populations in the Cascades Mountains (CA, USA). Of these, 30 randomly selected frogs were treated with itraconazole and the other 30 frogs served as experimental controls; all were released at the capture site. Bd prevalence was low at the time of treatment and did not differ between treated frogs and controls immediately following treatment. Following release, Bd prevalence gradually increased in controls but not in treated frogs, with noticeable (but still non-significant) differences 3 wk after treatment (27% [4/15] vs. 0% [0/13]) and strong differences 5 wk after treatment (67% [8/12] vs. 13% [1/8]). We did not detect any differences in Bd prevalence and load between experimental controls and untreated wild frogs during this time period. In spring 2013, we recaptured 7 treated frogs but none of the experimental control frogs, suggesting that over-winter survival was higher for treated frogs. The itraconazole treatment did appear to reduce growth rates: treated frogs weighed 22% less than control frogs 3 wk after treatment (0.7 vs. 0.9 g) and were 9% shorter than control frogs 5 wk after treatment (18.4 vs. 20.2 mm). However, for critically small populations, increased survival of the most at-risk life stage could prevent or delay extinction. Our results show that itraconazole treatment can be effective against Bd infection in wild amphibians, and therefore the beneficial effects on survivorship may outweigh the detrimental effects on growth. PMID:25590775

  11. Germ tube mediated invasion of Batrachochytrium dendrobatidis in amphibian skin is host dependent.

    Directory of Open Access Journals (Sweden)

    Pascale Van Rooij

    Full Text Available Batrachochytrium dendrobatidis (Bd is the causative agent of chytridiomycosis, a fungal skin disease in amphibians and driver of worldwide amphibian declines.We focussed on the early stages of infection by Bd in 3 amphibian species with a differential susceptibility to chytridiomycosis. Skin explants of Alytes muletensis, Litoria caerulea and Xenopus leavis were exposed to Bd in an Ussing chamber for 3 to 5 days. Early interactions of Bd with amphibian skin were observed using light microscopy and transmission electron microscopy. To validate the observations in vitro, comparison was made with skin from experimentally infected frogs. Additional in vitro experiments were performed to elucidate the process of intracellular colonization in L. caerulea. Early interactions of Bd with amphibian skin are: attachment of zoospores to host skin, zoospore germination, germ tube development, penetration into skin cells, invasive growth in the host skin, resulting in the loss of host cell cytoplasm. Inoculation of A. muletensis and L. caerulea skin was followed within 24 h by endobiotic development, with sporangia located intracellularly in the skin. Evidence is provided of how intracellular colonization is established and how colonization by Bd proceeds to deeper skin layers. Older thalli develop rhizoid-like structures that spread to deeper skin layers, form a swelling inside the host cell to finally give rise to a new thallus. In X. laevis, interaction of Bd with skin was limited to an epibiotic state, with sporangia developing upon the skin. Only the superficial epidermis was affected. Epidermal cells seemed to be used as a nutrient source without development of intracellular thalli. The in vitro data agreed with the results obtained after experimental infection of the studied frog species. These data suggest that the colonization strategy of B. dendrobatidis is host dependent, with the extent of colonization most likely determined by inherent

  12. Controlling wildlife fungal disease spread: in vitro efficacy of disinfectants against Batrachochytrium dendrobatidis and Mucor amphibiorum.

    Science.gov (United States)

    Webb, Rebecca; Philips, Annie; Speare, Rick; Connolly, Joanne; Berger, Lee

    2012-06-13

    Chytridiomycosis in amphibians, and mucormycosis in the platypus Ornithorhynchus anatinus and amphibians, are serious fungal diseases affecting these aquatic taxa. In Tasmania, Australia, the fungi that cause these diseases overlap in range along with Phytophthora cinnamomi (Pc), an invasive fungal plant pathogen. To identify disinfectants that may be useful to reduce anthropogenic spread of these fungi to uninfected wilderness areas, for example by bush walkers and forestry or fire-fighting operations, we tested 3 disinfectants and a fire-fighting foam against Mucor amphibiorum (Ma) and tested 1 disinfectant and the foam against Batrachochytrium dendrobatidis (Bd). Combining the present study with previous work we found Bd was more susceptible to all 4 chemicals than Ma. Phytoclean, a disinfectant used at 2 to 10% for 30 s to control Pc, killed cultures of Bd at 0.075% and Ma at 5%, when also applied for 30 s. The disinfectant F10sc was not effective against Ma at standard exposures, but previous work shows Bd is killed at 0.03% with a 1 min exposure. Path-X is effective against Bd at 0.001% with a 30 s exposure and killed Ma at 1% with a 5 min exposure. Forexpan S, a foam added to water at 0.1 to 1% to control forest fires, killed Bd but not Ma when used at 1% for 2 min. Therefore, Phytoclean and Path-X have broader efficacy, although Path-X has not been trialled against Pc. Interestingly a positive mating strain of Ma (from a platypus) was more resistant to disinfectants than a negative strain (from a frog). Current protocols against Pc that involve high concentrations (10%) of Phytoclean are likely to reduce spread of pathogenic wildlife fungi, which is important for protecting biodiversity. PMID:22691980

  13. Re-isolating Batrachochytrium dendrobatidis from an amphibian host increases pathogenicity in a subsequent exposure.

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    Forrest M R Brem

    Full Text Available Controlled exposure experiments can be very informative, however, they are based on the assumption that pathogens maintained on artificial media under long-term storage retain the infective and pathogenic properties of the reproducing pathogen as it occurs in a host. We observed that JEL284, an in vitro cultured and maintained isolate of Batrachochytrium dendrobatidis (Bd, was becoming less infectious with successive uses. We hypothesized that passing an isolate propagated on artificial media through an amphibian host would make the isolate more infectious and pathogenic in subsequent exposures. To test our hypothesis, we used two discreet steps, a reisolation step (step 1 and a comparative exposure step (step 2. In step 1, we exposed eastern spadefoot toads, Scaphiopus holbrooki, to JEL284 and JEL197, another isolate that had been maintained in vitro for over six years. We then re-isolated JEL284 only from a successful infection and named this new isolate JEL284(FMBa. JEL197 did not infect any amphibians and, thus, did not proceed to step 2. In step 2, we compared infectivity and pathogenicity (mortality and survival time of JEL284 and JEL284(FMBa by exposing 54 naïve S. holbrooki to three treatments (JEL284, JEL284(FMBa, and negative control with 18 individuals per group. We found that JEL284(FMBa caused higher mortality and decreased survival time in infected individuals when compared to JEL284 and negative controls. Thus, our data show that pathogenicity of Bd can decrease when cultured successively in media only and can be partially restored by passage through an amphibian host. Therefore, we have demonstrated that pathogenicity shifts can occur rapidly in this pathogen. Given the potential for shifts in pathogenicity demonstrated here, we suspect Bd to have similar potential in natural populations. We suggest that, when possible, the use of freshly isolated or cryopreserved Bd would improve the quality of controlled exposure experiments

  14. Widespread occurrence of Batrachochytrium dendrobatidis in contemporary and historical samples of the endangered Bombina pachypus along the Italian peninsula.

    Directory of Open Access Journals (Sweden)

    Daniele Canestrelli

    Full Text Available Batrachochytrium dendrobatidis is considered a main driver of the worldwide declines and extinctions of amphibian populations. Nonetheless, fundamental questions about its epidemiology, including whether it acts mainly as a "lone killer" or in conjunction with other factors, remain largely open. In this paper we analysed contemporary and historical samples of the endangered Apennine yellow-bellied toad (Bombina pachypus along the Italian peninsula, in order to assess the presence of the pathogen and its spreading dynamics. Once common throughout its range, B. pachypus started to decline after the mid-1990s in the northern and central regions, whereas no declines have been observed so far in the southern region. We show that Batrachochytrium dendrobatidis is currently widespread along the entire peninsula, and that this was already so at least as early as the late 1970s, that is, well before the beginning of the observed declines. This temporal mismatch between pathogen occurrence and host decline, as well as the spatial pattern of the declines, suggests that the pathogen has not acted as a "lone killer", but in conjunction with other factors. Among the potentially interacting factors, we identified two as the most probable, genetic diversity of host populations and recent climate changes. We discuss the plausibility of this scenario and its implications on the conservation of B. pachypus populations.

  15. Microsatellite primers for fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Gertsch, P J; Boomsma, JJ

    2002-01-01

    developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants.......We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...

  16. Microsatellite Primers for Fungus-Growing Ants

    DEFF Research Database (Denmark)

    Villesen Fredsted, Palle; Gertsch, Pia J.; Boomsma, Jacobus Jan (Koos)

    2002-01-01

    developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants.......We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...

  17. A new macrocyclic trichochecene from soil fungus

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    From fermentation broth of soil fungus 254-2 obtained from Yunnan province,a new macrocylic trichochecene was isolated.The structure was determined on the basis of spectroscopic evidences especially the 2-D NMR spectra.

  18. Dr Jekyll and Mrs Hyde: Risky hybrid sex by amphibian-parasitizing chytrids in the Brazilian Atlantic Forests.

    Science.gov (United States)

    Ghosh, Pria; Fisher, Matthew C

    2016-07-01

    In their article in this issue of Molecular Ecology, Jenkinson et al. () and colleagues address a worrying question-how could arguably the most dangerous pathogen known to science, Batrachochytrium dendrobatidis (Bd), become even more virulent? The answer: start having sex. Jenkinson et al. present a case for how the introduction into Brazil of the globally invasive lineage of Bd, BdGPL, has disrupted the relationship between native amphibians and an endemic Bd lineage, BdBrazil. BdBrazil is hypothesized to be native to the Atlantic Forest and so have a long co-evolutionary history with biodiverse Atlantic Forest amphibian community. The authors suggest that this has resulted in a zone of hybrid Bd genotypes which are potentially more likely to cause fatal chytridiomycosis than either parent lineage. The endemic-nonendemic Bd hybrid genotypes described in this study, and the evidence for pathogen translocation via the global amphibian trade presented, highlights the danger of anthropogenic pathogen dispersal. This research emphasizes that biosecurity regulations may have to refocus on lineages within species if we are to mitigate against the danger of new, possibly hypervirulent genotypes of pathogens emerging as phylogeographic barriers are breached. PMID:27373706

  19. Population estimates of Dendrobates tinctorius (Anura: Dendrobatidae at three sites in French Guiana and first record of chytrid infection

    Directory of Open Access Journals (Sweden)

    Elodie A. Courtois

    2012-06-01

    Full Text Available The Neotropics shelter the highest number of frog species on Earth and is also one of the regions where anurans are most threatened. Nonetheless, few data are available to assess the population status of Neotropical anurans. We studied three populations (Tresor, Favard, and Nouragues of the poison frog, Dendrobates tinctorius, in French Guiana and used Capture-Mark-Recapture (CMR to make robust estimations of the species’ density at these three sites. In addition, we assessed the prevalence of the pathogen fungal Batrachochytrium dendrobatidis (Bd in two populations (Favard and Nouragues. Based on the CMR protocol, the densities of frogs was 8.43 individuals/100 m² at Favard, 4.28 individuals/100 m² at Nouragues and from 2.30 to 4.67 individuals/100 m² at Tresor (depending on the CMR model used; these data provide a baseline for population densities of D. tinctorius in French Guiana, against which future population estimates can be compared. We found that 25 encounter events may be sufficient for stable population estimates, if the captures are concentrated in time. Bd was detected at both sites (Favard 7/152; Nouragues 3/18.

  20. Trypan blue dye is an effective and inexpensive way to determine the viability of Batrachochytrium dendrobatidis zoospores.

    Science.gov (United States)

    McMahon, Taegan A; Rohr, Jason R

    2014-06-01

    Batrachochytrium dendrobatidis (Bd) has been implicated in hundreds of amphibian declines and is the focus of a vast amount of research. Despite this, there is no reported efficient way to assess Bd viability. Discriminating between live and dead Bd would help determine the dose of live Bd zoospores and whether factors have lethal or sublethal effects on Bd. We tested whether trypan blue, a common stain to discriminate live and dead cells, could be used to assess Bd viability. We show that the proportion of live zoospores (zoospores that excluded the trypan blue dye) matched the proportion of known live zoospores added to cultures. In contrast, all of the zoosporangia stages of Bd stained blue. These results demonstrate that trypan blue can be used to determine the viability of Bd zoospores but not zoosporangia. We recommend using trypan blue to report the number of live zoospores to which hosts are exposed. PMID:24519684

  1. Amphibian chytridiomycosis: a review with focus on fungus-host interactions

    OpenAIRE

    Van Rooij, Pascale; Martel, An; Haesebrouck, Freddy; Pasmans, Frank

    2015-01-01

    Amphibian declines and extinctions are emblematic for the current sixth mass extinction event. Infectious drivers of these declines include the recently emerged fungal pathogens Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans (Chytridiomycota). The skin disease caused by these fungi is named chytridiomycosis and affects the vital function of amphibian skin. Not all amphibians respond equally to infection and host responses might range from resistant, over tolerant to susc...

  2. Host Identity Matters in the Amphibian-Batrachochytrium dendrobatidis System: Fine-Scale Patterns of Variation in Responses to a Multi-Host Pathogen

    OpenAIRE

    Gervasi, Stephanie; Gondhalekar, Carmen; Olson, Deanna H; BLAUSTEIN, ANDREW R.

    2013-01-01

    Species composition within ecological assemblages can drive disease dynamics including pathogen invasion, spread, and persistence. In multi-host pathogen systems, interspecific variation in responses to infection creates important context dependency when predicting the outcome of disease. Here, we examine the responses of three sympatric host species to a single fungal pathogen, Batrachochytrium dendrobatidis, which is associated with worldwide amphibian population declines and extinctions. U...

  3. A de novo Assembly of the Common Frog (Rana temporaria) Transcriptome and Comparison of Transcription Following Exposure to Ranavirus and Batrachochytrium dendrobatidis.

    OpenAIRE

    Price, S.J.; Garner, T. W.; Balloux, F.; Ruis, C.; Paszkiewicz, K. H.; Moore, K.; Griffiths, A. G.

    2015-01-01

    Amphibians are experiencing global declines and extinctions, with infectious diseases representing a major factor. In this study we examined the transcriptional response of metamorphic hosts (common frog, Rana temporaria) to the two most important amphibian pathogens: Batrachochytrium dendrobatidis (Bd) and Ranavirus. We found strong up-regulation of a gene involved in the adaptive immune response (AP4S1) at four days post-exposure to both pathogens. We detected a significant transcriptional ...

  4. Nuclear flow in a filamentous fungus

    CERN Document Server

    Hickey, Patrick C; Read, Nick; Glass, N Louise; Roper, Marcus

    2012-01-01

    The syncytial cells of a filamentous fungus consist of a mass of growing, tube-like hyphae. Each extending tip is fed by a continuous flow of nuclei from the colony interior, pushed by a gradient in turgor pressure. The myco-fluidic flows of nuclei are complex and multidirectional, like traffic in a city. We map out the flows in a strain of the model filamentous fungus {\\it N. crassa} that has been transformed so that nuclei express either hH1-dsRed (a red fluorescent nuclear protein) or hH1-GFP (a green-fluorescent protein) and report our results in a fluid dynamics video.

  5. Dentigerumycin: a bacterial mediator of an ant-fungus symbiosis

    DEFF Research Database (Denmark)

    Oh, Dong-Chan; Poulsen, Michael; Currie, Cameron R; Clardy, Jon

    2009-01-01

    Fungus-growing ants engage in mutualistic associations with both the fungus they cultivate for food and actinobacteria (Pseudonocardia spp.) that produce selective antibiotics to defend that fungus from specialized fungal parasites. We have analyzed one such system at the molecular level and found...... that the bacterium associated with the ant Apterostigma dentigerum produces dentigerumycin, a cyclic depsipeptide with highly modified amino acids, to selectively inhibit the associated parasitic fungus (Escovopsis sp.)....

  6. Open-Ended Experimentation with the Fungus Pilobolus.

    Science.gov (United States)

    Coble, Charles R.; Bland, Charles E.

    This paper describes open-ended experimentation with the fungus Pilobolus for laboratory work by high school students. The fungus structure and reproduction is described and sources of the fungus are suggested. Four areas for investigation are suggested: the effect of a diffuse light source, the effect of a point light source, the effect of light…

  7. Death from Fungus in the Soil

    Centers for Disease Control (CDC) Podcasts

    2012-12-17

    Dr. Shira Shafir, Assistant Professor of Epidemiology at the UCLA Fielding School of Public Health, discusses her study about fungus found in soil.  Created: 12/17/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 12/18/2012.

  8. Spread of Rare Fungus from Vancouver Island

    Centers for Disease Control (CDC) Podcasts

    2006-12-20

    Cryptococcus gattii, a rare fungus normally found in the tropics, has infected people and animals on Vancouver Island, Canada. Dr. David Warnock, Director, Division of Foodborne, Bacterial, and Mycotic Diseases, CDC, discusses public health concerns about further spread of this organism.  Created: 12/20/2006 by Emerging Infectious Diseases.   Date Released: 12/29/2006.

  9. Prevalence of Batrachochytrium dendrobatidis in Xenopus collected in Africa (1871-2000 and in California (2001-2010.

    Directory of Open Access Journals (Sweden)

    Vance T Vredenburg

    Full Text Available International trade of the invasive South African clawed frog (Xenopus laevis, a subclinical carrier of the fungal pathogen Batrachochytrium dendrobatis (Bd has been proposed as a major means of introduction of Bd into naïve, susceptible amphibian populations. The historical presence of Bd in the indigenous African population of Xenopus is well documented. However, there are no reports documenting the presence of Bd in wild Xenopus populations in the US, particularly in California where introduced populations are well-established after intentional or accidental release. In this report, a survey was conducted on 178 archived specimens of 6 species of Xenopus collected in Africa from 1871-2000 and on 23 archived specimens (all wild-caught Xenopus laevis collected in California, USA between 2001 and 2010. The overall prevalence rate of Bd in the tested Xenopus was 2.8%. The earliest positive specimen was X. borealis collected in Kenya in 1934. The overall prevalence of Bd in the X. laevis collected in California was 13% with 2 positive specimens from 2001 and one positive specimen from 2003. The positive Xenopus (3/23 collected in California were collected in 2001 (2/3 and 2003 (1/3. These data document the presence of Bd-infected wild Xenopus laevis in California. The findings reported here support the prevailing hypothesis that Bd was present as a stable, endemic infection in Xenopus populations in Africa prior to their worldwide distribution likely via international live-amphibian trade.

  10. Elevated Corticosterone Levels and Changes in Amphibian Behavior Are Associated with Batrachochytrium dendrobatidis (Bd Infection and Bd Lineage.

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    Caitlin R Gabor

    Full Text Available Few studies have examined the role hormones play in mediating clinical changes associated with infection by the parasite Batrachochytrium dendrobatidis (Bd. Glucocorticoid (GC hormones such as corticosteroids (CORT regulate homeostasis and likely play a key role in response to infection in amphibians. We explore the relationship between CORT release rates and Bd infection in tadpoles of the common midwife toad, Alytes obstetricians, using a non-invasive water-borne hormone collection method across seven populations. We further examined whether tadpoles of A. muletensis infected with a hypervirulent lineage of Bd, BdGPL, had greater CORT release rates than those infected with a hypovirulent lineage, BdCAPE. Finally, we examined the relationship between righting reflex and CORT release rates in infected metamorphic toads of A. obstetricans. We found an interaction between elevation and Bd infection status confirming that altitude is associated with the overall severity of infection. In tandem, increasing elevation was associated with increasing CORT release rates. Tadpoles infected with the hypervirulent BdGPL had significantly higher CORT release rates than tadpoles infected with BdCAPE showing that more aggressive infections lead to increased CORT release rates. Infected metamorphs with higher CORT levels had an impaired righting reflex, our defined experimental endpoint. These results provide evidence that CORT is associated with an amphibian's vulnerability to Bd infection, and that CORT is also affected by the aggressiveness of infection by Bd. Together these results indicate that CORT is a viable biomarker of amphibian stress.

  11. A reservoir species for the emerging Amphibian pathogen Batrachochytrium dendrobatidis thrives in a landscape decimated by disease.

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    Natalie M M Reeder

    Full Text Available Chytridiomycosis, a disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd, is driving amphibian declines and extinctions in protected areas globally. The introduction of invasive reservoir species has been implicated in the spread of Bd but does not explain the appearance of the pathogen in remote protected areas. In the high elevation (>1500 m Sierra Nevada of California, the native Pacific chorus frog, Pseudacris regilla, appears unaffected by chytridiomycosis while sympatric species experience catastrophic declines. We investigated whether P. regilla is a reservoir of Bd by comparing habitat occupancy before and after a major Bd outbreak and measuring infection in P. regilla in the field, monitoring susceptibility of P. regilla to Bd in the laboratory, examining tissues with histology to determine patterns of infection, and using an innovative soak technique to determine individual output of Bd zoospores in water. Pseudacris regilla persists at 100% of sites where a sympatric species has been extirpated from 72% in synchrony with a wave of Bd. In the laboratory, P. regilla carried loads of Bd as much as an order of magnitude higher than loads found lethal to sympatric species. Histology shows heavy Bd infection in patchy areas next to normal skin, a possible mechanism for tolerance. The soak technique was 77.8% effective at detecting Bd in water and showed an average output of 68 zoospores per minute per individual. The results of this study suggest P. regilla should act as a Bd reservoir and provide evidence of a tolerance mechanism in a reservoir species.

  12. Batrachochytrium dendrobatidis shows high genetic diversity and ecological niche specificity among haplotypes in the Maya Mountains of Belize.

    Directory of Open Access Journals (Sweden)

    Kristine Kaiser

    Full Text Available The amphibian pathogen Batrachochytrium dendrobatidis (Bd has been implicated in amphibian declines around the globe. Although it has been found in most countries in Central America, its presence has never been assessed in Belize. We set out to determine the range, prevalence, and diversity of Bd using quantitative PCR (qPCR and sequencing of a portion of the 5.8 s and ITS1-2 regions. Swabs were collected from 524 amphibians of at least 26 species in the protected areas of the Maya Mountains of Belize. We sequenced a subset of 72 samples that had tested positive for Bd by qPCR at least once; 30 samples were verified as Bd. Eight unique Bd haplotypes were identified in the Maya Mountains, five of which were previously undescribed. We identified unique ecological niches for the two most broadly distributed haplotypes. Combined with data showing differing virulence shown in different strains in other studies, the 5.8 s - ITS1-2 region diversity found in this study suggests that there may be substantial differences among populations or haplotypes. Future work should focus on whether specific haplotypes for other genomic regions and possibly pathogenicity can be associated with haplotypes at this locus, as well as the integration of molecular tools with other ecological tools to elucidate the ecology and pathogenicity of Bd.

  13. Distribution and pathogenicity of Batrachochytrium dendrobatidis in boreal toads from the grand teton area of western wyoming

    Science.gov (United States)

    Murphy, P.J.; St-Hilaire, S.; Bruer, S.; Corn, P.S.; Peterson, C.R.

    2009-01-01

    The pathogen Batrachochytrium dendrobatidis (Bd), which causes the skin disease chytridiomycosis, has been linked to amphibian population declines and extinctions worldwide. Bd has been implicated in recent declines of boreal toads, Bufo boreas boreas, in Colorado but populations of boreal toads in western Wyoming have high prevalence of Bd without suffering catastrophic mortality. In a field and laboratory study, we investigated the prevalence of Bd in boreal toads from the Grand Teton ecosystem (GRTE) in Wyoming and tested the pathogenicity of Bd to these toads in several environments. The pathogen was present in breeding adults at all 10 sites sampled, with a mean prevalence of 67%. In an experiment with juvenile toadlets housed individually in wet environments, 106 zoospores of Bd isolated from GRTE caused lethal disease in all Wyoming and Colorado animals within 35 days. Survival time was longer in toadlets from Wyoming than Colorado and in toadlets spending more time in dry sites. In a second trial involving Colorado toadlets exposed to 35% fewer Bd zoospores, infection peaked and subsided over 68 days with no lethal chytridiomycosis in any treatment. However, compared with drier aquaria with dry refuges, Bd infection intensity was 41% higher in more humid aquaria and 81% higher without dry refuges available. Our findings suggest that although widely infected in nature, Wyoming toads may escape chytridiomycosis due to a slight advantage in innate resistance or because their native habitat hinders Bd growth or provides more opportunities to reduce pathogen loads behaviorally than in Colorado. ?? 2009 International Association for Ecology and Health.

  14. Mountain Yellow-legged Frogs (Rana muscosa) did not Produce Detectable Antibodies in Immunization Experiments with Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Poorten, Thomas J; Stice-Kishiyama, Mary J; Briggs, Cheryl J; Rosenblum, Erica Bree

    2016-01-01

    Chytridiomycosis is a devastating infectious disease of amphibians caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). A growing number of studies have examined the role of amphibian adaptive immunity in response to this pathogen, with varying degrees of immune activation reported. Here we present immunologic data for the mountain yellow-legged frog, Rana muscosa, and the Sierra Nevada yellow-legged frog, Rana sierrae, which are two endangered and ecologically important species experiencing Bd-inflicted declines. Previous studies on these species that examined transcriptional response during Bd infection, and the effective of immunization, provided little evidence of immune activation to Bd. However, the studies did not directly assay immune effectors in the frog hosts. We performed experiments to examine antibody production, which is a hallmark of systemic adaptive immune activation. We used controlled laboratory experiments and enzyme-linked immunosorbent assays to examine the antibody response to Bd immunization and live Bd exposure. Rana muscosa and R. sierrae individuals did not produce detectable antibodies with the capacity to bind to denatured Bd antigens under our experimental conditions. While we cannot rule out antibody response to Bd in these species, our results suggest weak, poor, or inefficient production of antibodies to denatured Bd antigens. Our findings are consistent with susceptibility to chytridiomycosis in these species and suggest additional work is needed to characterize the potential for adaptive immunity. PMID:26540180

  15. Amphibian Symbiotic Bacteria Do Not Show a Universal Ability To Inhibit Growth of the Global Panzootic Lineage of Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Antwis, Rachael E; Preziosi, Richard F; Harrison, Xavier A; Garner, Trenton W J

    2015-06-01

    Microbiomes associated with multicellular organisms influence the disease susceptibility of hosts. The potential exists for such bacteria to protect wildlife from infectious diseases, particularly in the case of the globally distributed and highly virulent fungal pathogen Batrachochytrium dendrobatidis of the global panzootic lineage (B. dendrobatidis GPL), responsible for mass extinctions and population declines of amphibians. B. dendrobatidis GPL exhibits wide genotypic and virulence variation, and the ability of candidate probiotics to restrict growth across B. dendrobatidis isolates has not previously been considered. Here we show that only a small proportion of candidate probiotics exhibited broad-spectrum inhibition across B. dendrobatidis GPL isolates. Moreover, some bacterial genera showed significantly greater inhibition than others, but overall, genus and species were not particularly reliable predictors of inhibitory capabilities. These findings indicate that bacterial consortia are likely to offer a more stable and effective approach to probiotics, particularly if related bacteria are selected from genera with greater antimicrobial capabilities. Together these results highlight a complex interaction between pathogens and host-associated symbiotic bacteria that will require consideration in the development of bacterial probiotics for wildlife conservation. Future efforts to construct protective microbiomes should incorporate bacteria that exhibit broad-spectrum inhibition of B. dendrobatidis GPL isolates. PMID:25819964

  16. Phylogenetic distribution of symbiotic bacteria from Panamanian amphibians that inhibit growth of the lethal fungal pathogen Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Becker, Matthew H; Walke, Jenifer B; Murrill, Lindsey; Woodhams, Douglas C; Reinert, Laura K; Rollins-Smith, Louise A; Burzynski, Elizabeth A; Umile, Thomas P; Minbiole, Kevin P C; Belden, Lisa K

    2015-04-01

    The introduction of next-generation sequencing has allowed for greater understanding of community composition of symbiotic microbial communities. However, determining the function of individual members of these microbial communities still largely relies on culture-based methods. Here, we present results on the phylogenetic distribution of a defensive functional trait of cultured symbiotic bacteria associated with amphibians. Amphibians are host to a diverse community of cutaneous bacteria and some of these bacteria protect their host from the lethal fungal pathogen Batrachochytrium dendrobatidis (Bd) by secreting antifungal metabolites. We cultured over 450 bacterial isolates from the skins of Panamanian amphibian species and tested their interactions with Bd using an in vitro challenge assay. For a subset of isolates, we also completed coculture experiments and found that culturing isolates with Bd had no effect on inhibitory properties of the bacteria, but it significantly decreased metabolite secretion. In challenge assays, approximately 75% of the bacterial isolates inhibited Bd to some extent and these inhibitory isolates were widely distributed among all bacterial phyla. Although there was no clear phylogenetic signal of inhibition, three genera, Stenotrophomonas, Aeromonas and Pseudomonas, had a high proportion of inhibitory isolates (100%, 77% and 73%, respectively). Overall, our results demonstrate that antifungal properties are phylogenetically widespread in symbiotic microbial communities of Panamanian amphibians and that some functional redundancy for fungal inhibition occurs in these communities. We hope that these findings contribute to the discovery and development of probiotics for amphibians that can mitigate the threat of chytridiomycosis. PMID:25737297

  17. Persistence of the emerging pathogen Batrachochytrium dendrobatidis outside the amphibian host greatly increases the probability of host extinction.

    Science.gov (United States)

    Mitchell, Kate M; Churcher, Thomas S; Garner, Trenton W J; Fisher, Matthew C

    2008-02-01

    Pathogens do not normally drive their hosts to extinction; however, Batrachochytrium dendrobatidis, which causes amphibian chytridiomycosis, has been able to do so. Theory predicts that extinction can be caused by long-lived or saprobic free-living stages. The hypothesis that such a stage occurs in B. dendrobatidis is supported by the recent discovery of an apparently encysted form of the pathogen. To investigate the effect of a free-living stage of B. dendrobatidis on host population dynamics, a mathematical model was developed to describe the introduction of chytridiomycosis into a breeding population of Bufo bufo, parametrized from laboratory infection and transmission experiments. The model predicted that the longer that B. dendrobatidis was able to persist in water, either due to an increased zoospore lifespan or saprobic reproduction, the more likely it was that it could cause local B. bufo extinction (defined as decrease below a threshold level). Establishment of endemic B. dendrobatidis infection in B. bufo, with severe host population depression, was also possible, in agreement with field observations. Although this model is able to predict clear trends, more precise predictions will only be possible when the life history of B. dendrobatidis, including free-living stages of the life cycle, is better understood. PMID:18048287

  18. Surviving chytridiomycosis: differential anti-Batrachochytrium dendrobatidis activity in bacterial isolates from three lowland species of Atelopus.

    Directory of Open Access Journals (Sweden)

    Sandra V Flechas

    Full Text Available In the Neotropics, almost every species of the stream-dwelling harlequin toads (genus Atelopus have experienced catastrophic declines. The persistence of lowland species of Atelopus could be explained by the lower growth rate of Batrachochytrium dendrobatidis (Bd at temperatures above 25 °C. We tested the complementary hypothesis that the toads' skin bacterial microbiota acts as a protective barrier against the pathogen, perhaps delaying or impeding the symptomatic phase of chytridiomycosis. We isolated 148 cultivable bacterial strains from three lowland Atelopus species and quantified the anti-Bd activity through antagonism assays. Twenty-six percent (38 strains representing 12 species of the bacteria inhibited Bd growth and just two of them were shared among the toad species sampled in different localities. Interestingly, the strongest anti-Bd activity was measured in bacteria isolated from A. elegans, the only species that tested positive for the pathogen. The cutaneous bacterial microbiota is thus likely a fitness-enhancing trait that may (adaptation or not (exaptation have appeared because of natural selection mediated by chytridiomycosis. Our findings reveal bacterial strains for development of local probiotic treatments against chytridiomycosis and also shed light on the mechanisms behind the frog-bacteria-pathogen interaction.

  19. Surviving chytridiomycosis: differential anti-Batrachochytrium dendrobatidis activity in bacterial isolates from three lowland species of Atelopus.

    Science.gov (United States)

    Flechas, Sandra V; Sarmiento, Carolina; Cárdenas, Martha E; Medina, Edgar M; Restrepo, Silvia; Amézquita, Adolfo

    2012-01-01

    In the Neotropics, almost every species of the stream-dwelling harlequin toads (genus Atelopus) have experienced catastrophic declines. The persistence of lowland species of Atelopus could be explained by the lower growth rate of Batrachochytrium dendrobatidis (Bd) at temperatures above 25 °C. We tested the complementary hypothesis that the toads' skin bacterial microbiota acts as a protective barrier against the pathogen, perhaps delaying or impeding the symptomatic phase of chytridiomycosis. We isolated 148 cultivable bacterial strains from three lowland Atelopus species and quantified the anti-Bd activity through antagonism assays. Twenty-six percent (38 strains representing 12 species) of the bacteria inhibited Bd growth and just two of them were shared among the toad species sampled in different localities. Interestingly, the strongest anti-Bd activity was measured in bacteria isolated from A. elegans, the only species that tested positive for the pathogen. The cutaneous bacterial microbiota is thus likely a fitness-enhancing trait that may (adaptation) or not (exaptation) have appeared because of natural selection mediated by chytridiomycosis. Our findings reveal bacterial strains for development of local probiotic treatments against chytridiomycosis and also shed light on the mechanisms behind the frog-bacteria-pathogen interaction. PMID:22970314

  20. Body length of Hylodes cf. ornatus and Lithobates catesbeianus tadpoles, depigmentation of mouthparts, and presence of Batrachochytrium dendrobatidis are related Tamanho do corpo, despigmentação das partes bucais e presença de Batrachochytrium dendrobatidis estão relacionados em Hylodes cf. ornatus e Lithobates catesbeianus

    OpenAIRE

    CA. Vieira; LF. Toledo; JE. Longcore; JR. Longcore

    2013-01-01

    A fungal pathogen Batrachochytrium dendrobatidis (Bd), which can cause morbidity and death of anurans, has affected amphibian populations on a worldwide basis. Availability of pure cultures of Bd isolates is essential for experimental studies to understand the ecology of this pathogen. We evaluated the relationships of body length of Hylodes cf. ornatus and Lithobates catesbeianus tadpoles to depigmentation of mouthparts and determined if dekeratinization indicated an infection by Batrachochy...

  1. [Report on a fungus parasitizing Entamoeba histolytica].

    Science.gov (United States)

    Cao, C Q; Feng, Y S

    1989-01-01

    Infection of Entamoeba histolytica with chytridiaceous fungus Sphaerita was observed in some specimens obtained from a farmer and stained with iron-haematoxylin. The fungi were found in 78% of the cysts, mostly immature ones. Within the amoebae this parasite occurred singly, in groups, or in the form of a sporangium. It was located in the cytoplasm, the glycogen mass or the chromatoidal bars. In the same specimen, the parasitic fungus was also found in 18% of E. coli cysts; in 11% of E. nana cysts; while only one of 16 E. hartmanni cysts was parasitized. It is an interesting case of superimposed parasitism so far reported in China as well as a rare case of several species of amoebae being heavily involved with the same in the scientific literature. PMID:2548767

  2. SYSTEMIC INFECTION AND RELATED FUNGUS: AN OVERVIEW

    OpenAIRE

    Saha Rajsekhar; Mishra Aditya Kumar

    2011-01-01

    A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds (British English: moulds), as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which are separate from plants, animals, and bacteria. One major difference is that fungal cells have cell walls that contain chitin, unlike the cell walls of plants, which contain cellulose. Many fungi play a crucial role in decomposition (breaking things down)...

  3. The agricultural pathology of ant fungus gardens

    OpenAIRE

    Currie, Cameron R; Mueller, Ulrich G.; Malloch, David

    1999-01-01

    Gardens of fungus-growing ants (Formicidae: Attini) traditionally have been thought to be free of microbial parasites, with the fungal mutualist maintained in nearly pure “monocultures.” We conducted extensive isolations of “alien” (nonmutualistic) fungi from ant gardens of a phylogenetically representative collection of attine ants. Contrary to the long-standing assumption that gardens are maintained free of microbial pathogens and parasites, they are in fact host to specialized parasites th...

  4. Diversity of Andean amphibians of the Tamá National Natural Park in Colombia: a survey for the presence of Batrachochytrium dendrobatidis

    OpenAIRE

    Acevedo, A. A.; R. de Franco; Carrero, D. A.

    2016-01-01

    Changes in diversity and possible decreases in populations of amphibians have not yet been determined in many areas in the Andes. This study aimed to develop an inventory of the biodiversity of amphibians in the Andean areas of the Tamá National Natural Park (Tamá NNP) and to evaluate the patterns of infection by Batrachochytrium dendrobatidis (Bd) in preserved and degraded areas. We performed samplings focused on three habitats (forest, open areas and streams) in four localities from 2,000 t...

  5. Fungus-Growing Termites Originated in African Rain Forest

    DEFF Research Database (Denmark)

    Aanen, Duur Kornelis; Eggleton, Paul

    2005-01-01

    consumed (cf. [ [1] and [2] ]). Fungus-growing termites are found throughout the Old World tropics, in rain forests and savannas, but are ecologically dominant in savannas [ 3 ]. Here, we reconstruct the ancestral habitat and geographical origin of fungus-growing termites. We used a statistical model of...... fungus growing by termites is ecologically most successful under the variable, unfavorable conditions of the savanna, it seems to have evolved under the more constant and favorable conditions of the rain forest....

  6. Investigating differences across host species and scales to explain the distribution of the amphibian pathogen Batrachochytrium dendrobatidis.

    Directory of Open Access Journals (Sweden)

    Anna C Peterson

    Full Text Available Many pathogens infect more than one host species, and clarifying how these different hosts contribute to pathogen dynamics can facilitate the management of pathogens and can lend insight into the functioning of pathogens in ecosystems. In this study, we investigated a suite of native and non-native amphibian hosts of the pathogen Batrachochytrium dendrobatidis (Bd across multiple scales to identify potential mechanisms that may drive infection patterns in the Colorado study system. Specifically, we aimed to determine if: 1 amphibian populations vary in Bd infection across the landscape, 2 amphibian community composition predicts infection (e.g., does the presence or abundance of any particular species influence infection in others?, 3 amphibian species vary in their ability to produce infectious zoospores in a laboratory infection, 4 heterogeneity in host ability observed in the laboratory scales to predict patterns of Bd prevalence in the landscape. We found that non-native North American bullfrogs (Lithobates catesbeianus are widespread and have the highest prevalence of Bd infection relative to the other native species in the landscape. Additionally, infection in some native species appears to be related to the density of sympatric L. catesbeianus populations. At the smaller host scale, we found that L. catesbeianus produces more of the infective zoospore stage relative to some native species, but that this zoospore output does not scale to predict infection in sympatric wild populations of native species. Rather, landscape level infection relates most strongly to density of hosts at a wetland as well as abiotic factors. While non-native L. catesbeianus have high levels of Bd infection in the Colorado Front Range system, we also identified Bd infection in a number of native amphibian populations allopatric with L. catesbeianus, suggesting that multiple host species are important contributors to the dynamics of the Bd pathogen in this

  7. Batrachochytrium dendrobatidis and the collapse of anuran species richness and abundance in the Upper Manu National Park, Southeastern Peru.

    Science.gov (United States)

    Catenazzi, Alessandro; Lehr, Edgar; Rodriguez, Lily O; Vredenburg, Vance T

    2011-04-01

    Amphibians are declining worldwide, but these declines have been particularly dramatic in tropical mountains, where high endemism and vulnerability to an introduced fungal pathogen, Batrachochytrium dendrobatidis (Bd), is associated with amphibian extinctions. We surveyed frogs in the Peruvian Andes in montane forests along a steep elevational gradient (1200-3700 m). We used visual encounter surveys to sample stream-dwelling and arboreal species and leaf-litter plots to sample terrestrial-breeding species. We compared species richness and abundance among the wet seasons of 1999, 2008, and 2009. Despite similar sampling effort among years, the number of species (46 in 1999) declined by 47% between 1999 and 2008 and by 38% between 1999 and 2009. When we combined the number of species we found in 2008 and 2009, the decline from 1999 was 36%. Declines of stream-dwelling and arboreal species (a reduction in species richness of 55%) were much greater than declines of terrestrial-breeding species (reduction of 20% in 2008 and 24% in 2009). Similarly, abundances of stream-dwelling and arboreal frogs were lower in the combined 2008-2009 period than in 1999, whereas densities of frogs in leaf-litter plots did not differ among survey years. These declines may be associated with the infection of frogs with Bd. B. dendrobatidis prevalence correlated significantly with the proportion of species that were absent from the 2008 and 2009 surveys along the elevational gradient. Our results suggest Bd may have arrived at the site between 1999 and 2007, which is consistent with the hypothesis that this pathogen is spreading in epidemic waves along the Andean cordilleras. Our results also indicate a rapid decline of frog species richness and abundance in our study area, a national park that contains many endemic amphibian species and is high in amphibian species richness. PMID:21054530

  8. Metabolites from mangrove endophytic fungus Dothiorella sp.

    Institute of Scientific and Technical Information of China (English)

    XUQingyan; WANGJianfeng; HUANGYaojian; ZHENGZhonghui; SONGSiyang; ZHANGYongmin; SUWenjin

    2004-01-01

    Mangroves are special woody plant communities in the intertidal zone of tropical and subtropical coasts. They prove to be a natural microorganisms and new metabolites storage. In the study of mangrove endophytic fungi metabolites, four new compounds, Compounds 1, 2, 3 and 4, as well as a known octaketide, cytosporone B (5), are isolated from an endophytic fungus, Dothiorella sp., HTF3. They all show cytotoxic activities. The elucidation of these structures is mainly based on 1D/2D NMR and ESI-MS spectral analyses.

  9. Innate immune system targets asthma-linked fungus for destruction

    OpenAIRE

    Whyte, Barry James

    2008-01-01

    A new study shows that the innate immune system of humans is capable of killing a fungus linked to airway inflammation, chronic rhinosinusitis, and bronchial asthma. Researchers at Mayo Clinic and the Virginia Bioinformatics Institute at Virginia Tech have revealed that eosinophils, a particular type of white blood cell, exert a strong immune response against the environmental fungus Alternaria alternata.

  10. Phomalactone from a phytopathogenic fungus infecting Zinnia elegans (Asteraceae) leaves

    Science.gov (United States)

    Zinnia elegans plants are infected by a fungus that causes necrosis with dark red spots particularly in late spring to the middle of summer in the Mid-South part of the United States. This fungal disease when untreated causes the leaves to wilt and eventually kills the plant. The fungus was isolated...

  11. CHARACTERIZATION OF AN ANAEROBIC FUNGUS FROM LLAMA FECES

    NARCIS (Netherlands)

    MARVINSIKKEMA, FD; LAHPOR, GA; KRAAK, MN; GOTTSCHAL, JC; PRINS, RA

    1992-01-01

    An anaerobic fungus was isolated from Hama faeces. Based on its morphological characteristics, polyflagellated zoospores, extensive rhizoid system and the formation of monocentric colonies, the fungus is assigned to the genus Neocallimastix. Neocallimastix sp. L2 is able to grow on several poly-, ol

  12. New Development Trend of Edible Fungus Industry in China

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    We elaborate support system of edible fungus industry from outlook on ecological economic development, legislation and standardization of variety approval, multiple-function innovation platform of industrial development research, and perfect talent cultivation and education system. Besides, we analyze the development trend of edible fungus industry from competitive advantages, position and role in national food security, industrial development trend driven by internal demand, diversified industrial development model, division of labor within the industry, and expansion of industrial chain. Then, from the point of zoning and planning of edible fungus industry, we put forward suggestions that it should start from modern industrial system and take the industrial cluster development and optimization as guidance. In addition, we present technical innovation direction of industrial development. It is proposed to strengthen propaganda, build industrial cultural atmosphere, and expand social cognition degree of edible fungus industry to promote its redevelopment. Finally, it is expected to promote international influence of edible fungus industry through experts appealing for policy support.

  13. Antimicrobial chemical constituents from endophytic fungus Phomasp.

    Institute of Scientific and Technical Information of China (English)

    Hidayat Hussain; Siegfried Draeger; Barbara Schulz; Karsten Krohn; Ines Kock; Ahmed Al-Harrasi; Ahmed Al-Rawahi; Ghulam Abbas; Ivan R Green; Afzal Shah; Amin Badshah; Muhammad Saleem

    2014-01-01

    Objective:To evaluate the antimicrobial potential of different extracts of the endophytic fungus Phomasp. and the tentative identification of their active constituents.Methods:The extract and compounds were screened for antimicrobial activity using theAgarWellDiffusionMethod. Four compounds were purified using column chromatography and their structures were assigned using1H and13CNMR spectra,DEPT,2DCOSY,HMQC andHMBC experiments.Results:The ethyl acetate fraction ofPhomasp. showed good antifungal, antibacterial, and algicidal properties.One new dihydrofuran derivative, named phomafuranol(1), together with three known compounds, phomalacton(2),(3R)-5-hydroxymellein(3) and emodin(4) were isolated from the ethyl acetate fraction ofPhomasp.Preliminary studies indicated that phomalacton(2) displayed strong antibacterial, good antifungal and antialgal activities.Similarly(3R)-5-hydroxymellein (3) and emodin(4) showed good antifungal, antibacterial and algicidal properties.Conclusions:Antimicrobial activities of the ethyl acetate fraction of the endophytic fungusPhomasp. and isolated compounds clearly demonstrate thatPhomasp. and its active compounds represent a great potential for the food, cosmetic and pharmaceutical industries.

  14. Effects of Biotic and Abiotic Setting on a Host-Pathogen Relationship: How Environmental and Community Characteristics Influence Infection Prevalence and Intensity of Amphibian Chytrid on California's Central Coast

    OpenAIRE

    Hemingway, Valentine

    2015-01-01

    In the face of swift anthropogenic change, it is essential to examine the broad ecological context for species of concern using a variety of approaches in order to understand their interactions in a natural context. Host-pathogen relationships offer a close interaction to examine how each are acted upon by biotic and abiotic conditions. Batrachochytrium dendrobatidis, an emerging infectious disease of amphibians, has been implicated with wholesale loss and marked declines in amphibian speci...

  15. Bioactive Triterpenes from the Fungus Piptoporus betulinus

    Directory of Open Access Journals (Sweden)

    Zeyad Alresly

    2015-08-01

    Full Text Available Phytochemical investigation of the ethyl acetate extract of the fruiting bodies from the basidiomycete Piptoporus betulinus led to the isolation of a new bioactive lanostane triterpene identified as 3 b -acetoxy-16-hydroxy-24-oxo-5α-lanosta-8- ene-21-oic acid (1. In addition, ten known triterpenes, polyporenic acid A (5, polyporenic acid C (4, three derivatives of polyporenic acid A (8, 10, 11, betulinic acid (3, betulin (2, ergosterol peroxide (6, 9,11-dehydroergosterol peroxide (7, and fomefficinic acid (9, were also isolated from the fungus. All isolated compounds were tested for antimicrobial activity against some Gram-positive and Gram-negative bacteria as well as against a fungal strain. The new triterpene and some of the other compounds showed antimicrobial activity against Gram-positive bacteria.

  16. SYSTEMIC INFECTION AND RELATED FUNGUS: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    Saha Rajsekhar

    2011-06-01

    Full Text Available A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds (British English: moulds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which are separate from plants, animals, and bacteria. One major difference is that fungal cells have cell walls that contain chitin, unlike the cell walls of plants, which contain cellulose. Many fungi play a crucial role in decomposition (breaking things down and returning nutrients to the soil. They are also used in medicine, an example is the antibiotic penicillin, as well as in industry and food preparation. In the present time the microbes are to be seen as disease causing organisms harming the mankind. The harm done by this community cannot be taken lightly as they are also useful in many ways. The above article is an effort to bring out the various fungal issued related to human.

  17. Comparative studies of the secretome of fungus-growing ants

    DEFF Research Database (Denmark)

    Linde, Tore; Grell, Morten Nedergaard; Schiøtt, Morten;

    2009-01-01

    Leafcutter ants of the species Acromyrmex echinatior live in symbiosis with the fungus Leucoagaricus gongylophorus. The ants harvest fragments of leaves and carry them to the nest where they place the material on the fungal colony. The fungus secretes a wide array of proteins to degrade the leaves...... into nutrients that the ants can feed on. The focus of this study is to discover, characterize and compare the secreted proteins. In order to do so cDNA libraries are constructed from mRNA extracted from the fungus material. The most efficient technology to screen cDNA libraries selectively for...

  18. A de novo Assembly of the Common Frog (Rana temporaria Transcriptome and Comparison of Transcription Following Exposure to Ranavirus and Batrachochytrium dendrobatidis.

    Directory of Open Access Journals (Sweden)

    Stephen J Price

    Full Text Available Amphibians are experiencing global declines and extinctions, with infectious diseases representing a major factor. In this study we examined the transcriptional response of metamorphic hosts (common frog, Rana temporaria to the two most important amphibian pathogens: Batrachochytrium dendrobatidis (Bd and Ranavirus. We found strong up-regulation of a gene involved in the adaptive immune response (AP4S1 at four days post-exposure to both pathogens. We detected a significant transcriptional response to Bd, covering the immune response (innate and adaptive immunity, complement activation, and general inflammatory responses, but relatively little transcriptional response to Ranavirus. This may reflect the higher mortality rates found in wild common frogs infected with Ranavirus as opposed to Bd. These data provide a valuable genomic resource for the amphibians, contribute insight into gene expression changes after pathogen exposure, and suggest potential candidate genes for future host-pathogen research.

  19. A model for the interaction of frog population dynamics with Batrachochytrium dendrobaties, Janthinobacterium lividium and temperature and its implication for chytridiomycosis management

    Science.gov (United States)

    Ackleh, Azmy S.; Carter, Jacoby; Chellamuthu, Vinodh K.; Ma, Baoling

    2016-01-01

    Chytridiomycosis is an emerging disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) that poses a serious threat to frog populations worldwide. Several studies have shown that inoculation of bacterial species Janthinobacterium lividum (Jl) can mitigate the impact of the disease. However, there are many questions regarding this interaction. A mathematical model of a frog population infected with chytridiomycosis is developed to investigate how the inoculation of Jl could reduce the impact of Bd disease on frogs. The model also illustrates the important role of temperature in disease dynamics. The model simulation results suggest possible control strategies for Jl to limit the impact of Bd in various scenarios. However, a better knowledge of Jl life cycle is needed to fully understand the interaction of Jl, Bd, temperature and frogs.

  20. Fungal Garden Making inside Bamboos by a Non-Social Fungus-Growing Beetle

    OpenAIRE

    Toki, Wataru; Takahashi, Yukiko; Togashi, Katsumi

    2013-01-01

    In fungus-growing mutualism, it is indispensable for host animals to establish gardens of the symbiotic fungus as rapidly as possible. How to establish fungal gardens has been well-documented in social fungus-farming insects, whereas poorly documented in non-social fungus-farming insects. Here we report that the non-social, fungus-growing lizard beetle Doubledaya bucculenta (Coleoptera: Erotylidae: Languriinae) transmits the symbiotic yeast Wickerhamomyces anomalus from the ovipositor-associa...

  1. Morphophysiological Differences between the Metapleural Glands of Fungus-Growing and Non–Fungus-Growing Ants (Hymenoptera, Formicidae)

    OpenAIRE

    Vieira, Alexsandro Santana; Bueno, Odair Correa; Camargo-Mathias, Maria Izabel

    2012-01-01

    The metapleural gland is an organ exclusive to ants. Its main role is to produce secretions that inhibit the proliferation of different types of pathogens. The aim of the present study was to examine the morphophysiological differences between the metapleural gland of 3 non–fungus-growing ants of the tribes Ectatommini, Myrmicini, and Blepharidattini and that of 5 fungus-growing ants from 2 basal and 3 derived attine genera. The metapleural gland of the non–fungus-growing ants and the basal a...

  2. Evolutionary patterns of proteinase activity in attine ant fungus gardens

    DEFF Research Database (Denmark)

    Semenova, Tatyana; Hughes, David Peter; Boomsma, Jacobus Jan;

    2011-01-01

    of evolutionary more derived fungal symbionts. This notion is also supported by buffering capacities of fungus gardens at pH 5.2 being remarkably high, and suggests that the fungal symbiont actively helps to maintain garden acidity at this specific level. Metalloproteinases dominated the activity profiles....... Conclusions: Proteinase pH optima and buffering capacities of fungal symbionts appear to have evolved remarkable adaptations to living in obligate symbiosis with farming ants. Although the functional roles of serine and metalloproteinases in fungus gardens are unknown, the differential production...... hypothesized that fungal proteinase activity may have been under selection for efficiency and that different classes of proteinases might be involved. Results: We determined proteinase activity profiles across a wide pH range for fungus gardens of 14 Panamanian species of fungus-growing ants, representing...

  3. Long-term endemism of two highly divergent lineages of the amphibian-killing fungus in the Atlantic Forest of Brazil.

    Science.gov (United States)

    Rodriguez, D; Becker, C G; Pupin, N C; Haddad, C F B; Zamudio, K R

    2014-02-01

    The recent global spread of the amphibian-killing fungus [Batrachochytrium dendrobatidis (Bd)] has been closely tied to anthropogenic activities; however, regional patterns of spread are not completely understood. Using historical samples, we can test whether Bd was a spreading or endemic pathogen in a region within a particular time frame, because those two disease states provide different predictions for the regional demographic dynamics and population genetics of Bd. Testing historical patterns of pathogen prevalence and population genetics under these predictions is key to understanding the evolution and origin of Bd. Focusing on the Atlantic Forest (AF) of Brazil, we used qPCR assays to determine the presence or absence of Bd on 2799 preserved postmetamorphic anurans collected between 1894 and 2010 and used semi-nested PCRs to determine the frequency of rRNA ITS1 haplotypes from 52 samples. Our earliest date of detection was 1894. A mean prevalence of 23.9% over time and spatiotemporal patterns of Bd clusters indicate that Bd has been enzootic in the Brazilian AF with no evidence of regional spread within the last 116 years. ITS1 haplotypes confirm the long-term presence of two divergent strains of Bd (BdGPL and Bd-Brazil) and three spatiotemporally broad genetic demes within BdGPL, indicating that Bd was not introduced into southeast Brazil by the bullfrog trade. Our data show that the evolutionary history and pathogen dynamics of Bd in Brazil is better explained by the endemic pathogen hypothesis. PMID:24471406

  4. Solubilization of lignin by the ruminal anaerobic fungus Neocallimastix patriciarum.

    OpenAIRE

    McSweeney, C S; Dulieu, A; Katayama, Y; Lowry, J B

    1994-01-01

    The ability of the ruminal anaerobic phycomycete Neocallimastix patriciarum to digest model lignin compounds and lignified structures in plant material was studied in batch culture. The fungus did not degrade or transform model lignin compounds that were representative of the predominant intermonomer linkages in lignin, nor did it solubilize acid detergent lignin that had been isolated from spear grass. In a stem fraction of sorghum, 33.6% of lignin was apparently solubilized by the fungus. S...

  5. Contributions to the study of Pseudopeziza trifolii (Bernh. Fuck. fungus

    Directory of Open Access Journals (Sweden)

    Olga PALL

    1966-08-01

    Full Text Available The present paper communicates the results of the laboratory experiments concerning the behaviour of the Pseudopeziza trifolii (Bernh. Fuck. fungus that produces the clover brown leaf spot, in different culture mediums. The mycelium of the fungus develops at its best on the peptone-glucose-agar medium. The appearance of pycnides of Sporonema phacidioides Desm. type in vitro, has been reported for the fourth time in Romania especially developing on the potatoe-dextrosis-agar and plum-agar mediums.

  6. Isolation and Identification of Glucoamylase Producer Fungus from Sago Hampas

    OpenAIRE

    Alfi Asben; Tun Tedja Irawadi2)

    2013-01-01

    Waste of sago processing, notably hampas (ela) still contains sago starch is waste that has not been utilized optimally yet  and causing pollution. Isolation and identification of glucoamylase producer fungus of sago hampas waste  were aims to obtain isolates that have gluco-amylolytic properties, and to know glucoamylase activity of selected fungus isolates after grown on artificial medium.  Indegeneous isolates that can produced glucoamylase will be use to get sugar hidrolysate from starch ...

  7. New aquatic sites of the fungus Sommerstorffia spinosa

    OpenAIRE

    Bazyli Czeczuga; Bożena Mazalska; Mirosława Orłowska

    2014-01-01

    When studying zoosporic fungi in the waters of northeastern Poland tbe authors found new sites of a rare fungus - Sommerstorffia spinosa Arnaudow. Its growth was observed in water samples collected from limnologically different reservoirs, from the spring Jaroszówka, the oligotrophic type (Lake Białe), through mesotrophic (Lake Wigry) to the polytrophic type (pond Fosa with high content of hydrogen sulphide under ice cover). This fungus was also found in the river Biała, which flowing through...

  8. ADR: An atypical presentation of rare dematiaceous fungus

    Directory of Open Access Journals (Sweden)

    J Karthika

    2014-01-01

    Full Text Available The association of fungus in allergic fungal rhino sinusitis has been around 200 times in the world literature. As per the available literature, the most common agent identified so far appears to be ASPERGILLUS, though the condition is increasingly associated with Dematiaceous fungi. Here we report for the first time the presence of unusual fungus in allergic rhino sinusitis, which has not been reported so far.

  9. Anthraquinones from the Fungus Dermocybe sanguinea as Textile Dyes

    OpenAIRE

    RÀisÀnen, Riikka

    2009-01-01

    This study is based on the multidiciplinary approach of using natural colorants as textile dyes. The author was interested in both the historical and traditional aspects of natural dyeing as well as the modern industrial applications of the pure natural compounds. In the study, the anthraquinone compounds were isolated as aglycones from the ectomycorrhizal fungus Dermocybe sanguinea. The endogenous beta-glucosidase of the fungus was used to catalyse the hydrolysis of the O-glycosyl linka...

  10. New Development Trend of Edible Fungus Industry in China

    OpenAIRE

    Lu, Min; Li, Yu

    2012-01-01

    We elaborate support system of edible fungus industry from outlook on ecological economic development, legislation and standardization of variety approval, multiple-function innovation platform of industrial development research, and perfect talent cultivation and education system. Besides, we analyze the development trend of edible fungus industry from competitive advantages, position and role in national food security, industrial development trend driven by internal demand. diversified indu...

  11. Solubilization of diabase and phonolite dust by filamentous fungus

    Directory of Open Access Journals (Sweden)

    Juliana Andréia Vrba Brandão

    2014-10-01

    Full Text Available The objective of this study was to evaluate the effect of the fungus Aspergillus niger strain CCT4355 in the release of nutrients contained in two types of rock powder (diabase and phonolite by means of in vitro solubilization trials. The experimental design was completely randomized in a 5 x 4 factorial design with three replications. It was evaluated five treatments (phonolite dust + culture medium; phonolite dust + fungus + culture medium; diabase powder + culture medium; diabase powder + fungus + culture medium and fungus + culture medium and four sampling dates (0, 10, 20 and 30 days. Rock dust (0.4% w/v was added to 125 mL Erlenmeyer flasks containing 50 mL of liquid culture medium adapted to A. niger. The flasks were incubated at 30°C for 30 days, and analysis of pH (in water, titratable acidity, and concentrations of soluble potassium, calcium, magnesium, zinc, iron and manganese were made. The fungus A. niger was able to produce organic acids that solubilized ions. This result indicates its potential to alter minerals contained in rock dust, with the ability to interact in different ways with the nutrients. A significant increase in the amount of K was found in the treatment with phonolite dust in the presence of the fungus. The strain CCT4355 of A. niger can solubilize minerals contained in these rocks dust.

  12. Isolated Polynucleotides and Methods of Promoting a Morphology in a Fungus

    Science.gov (United States)

    Lasure, Linda L. [Fall City, WA; Dai, Ziyu [Richland, WA

    2008-10-21

    The invention includes isolated polynucleotide molecules that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention includes a method of enhancing a bioprocess utilizing a fungus. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to a promoter. The polynucleotide sequence is expressed to promote a first morphology. The first morphology of the transformed fungus enhances a bioprocess relative to the bioprocess utilizing a second morphology.

  13. Widespread amphibian extinctions from epidemic disease driven by global warming.

    Science.gov (United States)

    Pounds, J Alan; Bustamante, Martín R; Coloma, Luis A; Consuegra, Jamie A; Fogden, Michael P L; Foster, Pru N; La Marca, Enrique; Masters, Karen L; Merino-Viteri, Andrés; Puschendorf, Robert; Ron, Santiago R; Sánchez-Azofeifa, G Arturo; Still, Christopher J; Young, Bruce E

    2006-01-12

    As the Earth warms, many species are likely to disappear, often because of changing disease dynamics. Here we show that a recent mass extinction associated with pathogen outbreaks is tied to global warming. Seventeen years ago, in the mountains of Costa Rica, the Monteverde harlequin frog (Atelopus sp.) vanished along with the golden toad (Bufo periglenes). An estimated 67% of the 110 or so species of Atelopus, which are endemic to the American tropics, have met the same fate, and a pathogenic chytrid fungus (Batrachochytrium dendrobatidis) is implicated. Analysing the timing of losses in relation to changes in sea surface and air temperatures, we conclude with 'very high confidence' (> 99%, following the Intergovernmental Panel on Climate Change, IPCC) that large-scale warming is a key factor in the disappearances. We propose that temperatures at many highland localities are shifting towards the growth optimum of Batrachochytrium, thus encouraging outbreaks. With climate change promoting infectious disease and eroding biodiversity, the urgency of reducing greenhouse-gas concentrations is now undeniable. PMID:16407945

  14. Rock Phosphate Solubilization Mechanisms of One Fungus and One Bacterium

    Institute of Scientific and Technical Information of China (English)

    LIN Qi-mei; ZHAO Xiao-rong; ZHAO Zi-juan; LI Bao-guo

    2002-01-01

    Many microorganisms can dissolve the insoluble phosphates like apatite. However, the mechanisms are still not clear. This study was an attempt to investigate the mechanisms of rock phosphate solubilization by an Aspergillus 2TCiF2 and an Arthrobacter1TCRi7. The results indicated that the fungus produced a large amount of organic acids, mainly oxalic acid. The total quantity of the organic acids produced by the fungus was 550 times higher than that by the bacterium. Different organic acids had completely different capacities to solubilize the rock. Oxalic acid and citric acid had stronger capacity to dissolve the rock than malic acid, tartaric acid, lactic acid, acetic acid, malonic acid and succinic acid. The fungus solubilized the rock through excreting both proton and organic acids. The rock solubilization of the bacterium depended on only proton.

  15. Evaluating the links between climate, disease spread, and amphibian declines.

    Science.gov (United States)

    Rohr, Jason R; Raffel, Thomas R; Romansic, John M; McCallum, Hamish; Hudson, Peter J

    2008-11-11

    Human alteration of the environment has arguably propelled the Earth into its sixth mass extinction event and amphibians, the most threatened of all vertebrate taxa, are at the forefront. Many of the worldwide amphibian declines have been caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd), and two contrasting hypotheses have been proposed to explain these declines. Positive correlations between global warming and Bd-related declines sparked the chytrid-thermal-optimum hypothesis, which proposes that global warming increased cloud cover in warm years that drove the convergence of daytime and nighttime temperatures toward the thermal optimum for Bd growth. In contrast, the spatiotemporal-spread hypothesis states that Bd-related declines are caused by the introduction and spread of Bd, independent of climate change. We provide a rigorous test of these hypotheses by evaluating (i) whether cloud cover, temperature convergence, and predicted temperature-dependent Bd growth are significant positive predictors of amphibian extinctions in the genus Atelopus and (ii) whether spatial structure in the timing of these extinctions can be detected without making assumptions about the location, timing, or number of Bd emergences. We show that there is spatial structure to the timing of Atelopus spp. extinctions but that the cause of this structure remains equivocal, emphasizing the need for further molecular characterization of Bd. We also show that the reported positive multi-decade correlation between Atelopus spp. extinctions and mean tropical air temperature in the previous year is indeed robust, but the evidence that it is causal is weak because numerous other variables, including regional banana and beer production, were better predictors of these extinctions. Finally, almost all of our findings were opposite to the predictions of the chytrid-thermal-optimum hypothesis. Although climate change is likely to play an important role in worldwide amphibian declines

  16. Isolation and identification of iron ore-solubilising fungus

    Directory of Open Access Journals (Sweden)

    Damase Khasa

    2010-09-01

    Full Text Available Potential mineral-solubilising fungi were successfully isolated from the surfaces of iron ore minerals. Four isolates were obtained and identified by molecular and phylogenetic methods as close relatives of three different genera, namely Penicillium (for isolate FO, Alternaria (for isolates SFC2 and KFC1 and Epicoccum (for isolate SFC2B. The use of tricalcium phosphate (Ca3(PO42in phosphate-solubilising experiments confirmed isolate FO as the only phosphate solubiliser among the isolated fungi. The bioleaching capabilities of both the fungus and its spent liquid medium were tested and compared using two types of iron ore materials, conglomerate and shale, from the Sishen Iron Ore Mine as sources of potassium (K and phosphorus (P. The spent liquid medium removed more K (a maximum of 32.94% removal, from conglomerate, than the fungus (a maximum of 21.36% removal, from shale. However, the fungus removed more P (a maximum of 58.33% removal, from conglomerate than the spent liquid medium (a maximum of 29.25% removal, from conglomerate. The results also indicated a potential relationship between the removal of K or P and the production of organic acids by the fungus. A high production of gluconic acid could be related to the ability of the fungus to reduce K and P. Acetic, citric and maleic acids were also produced by the fungus, but in lower quantities. In addition, particle size and iron ore type were also shown to have significant effects on the removal of potassium and phosphorus from the iron ore minerals. We therefore conclude that the spent liquid medium from the fungal isolate FO can potentially be used for biobeneficiation of iron ore minerals.

  17. A new cytosporone derivative from the endophytic fungus Cytospora sp.

    Science.gov (United States)

    Takano, Tomoya; Koseki, Takuya; Koyama, Hiromasa; Shiono, Yoshihito

    2014-07-01

    Japanese oak wilt (JOW) is a tree disease caused by the fungus Raffaelea quercivora, which is vectored by the ambrosia beetle, Platypus quercivorus. In a screening study of the inhibitory active compounds from fungi, a new cytosporone analogue, compound 1, was isolated from the endophytic fungus Cytospora sp. TT-10 isolated from Japanese oak, together with the known compounds, integracin A (2), cytosporones N (3) and A (4). Their structures were determined by extensive 1D- and 2D-NMR spectroscopic and mass spectral analyses. Compound 1 was identified as 4,5-dihydroxy-3-heptylphthalide and named cytosporone E. Compounds 2 and 3 showed antimicrobial activity against Raffaelea quercivora. PMID:25230507

  18. Source of fungus contamination of hydrophilic soft contact lenses.

    Science.gov (United States)

    Gasset, A R; Mattingly, T P; Hood, I

    1979-09-01

    Fungus infiltration within hydrophilic lenses has been a rare finding. This case report confirms previous findings that fungal contamination of hydrophilic contact lens is possible. The present report, to our knowledge, is the first demonstration of the association of fungus from contaminated cosmetics with hydrophilic contact lenses. It is important to be aware of the possibility of fungal invasion of hydrophilic lenses, as well as to be able to differentiate this from the more common harmless spot formation. On the basis of this study, good lid hygiene, strict adherence to the sterilization procedure, and discontinuance of any soft hydrophilic contact lenses with spot formation seems appropriate. PMID:556154

  19. Transformation of Metalaxyl by the Fungus Syncephalastrum racemosum†

    OpenAIRE

    Zheng, Zhong; Liu, Shu-Yen; Freyer, Alan J.; Bollag, Jean-Marc

    1989-01-01

    The fungus Syncephalastrum racemosum (Cohn) Schroeter was found to transform the fungicide metalaxyl [N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-alanine methyl ester] in pure culture. After 21 days of incubation in a basal medium amended with 5 μg of metalaxyl per ml, more than 80% of the compound was transformed by the fungus. The transformation rates decreased as the concentrations of metalaxyl increased from 5 to 100 μg/ml. No transformation was observed when the concentration of metalaxyl w...

  20. Roles of Peroxisomes in the Rice Blast Fungus.

    Science.gov (United States)

    Chen, Xiao-Lin; Wang, Zhao; Liu, Caiyun

    2016-01-01

    The rice blast fungus, Magnaporthe oryzae, is a model plant pathogenic fungus and is a severe threat to global rice production. Over the past two decades, it has been found that the peroxisomes play indispensable roles during M. oryzae infection. Given the importance of the peroxisomes for virulence, we review recent advances of the peroxisomes roles during M. oryzae infection processes. We firstly introduce the molecular mechanisms and life cycles of the peroxisomes. And then, metabolic functions related to the peroxisomes are also discussed. Finally, we provide an overview of the relationship between peroxisomes and pathogenicity. PMID:27610388

  1. Experimental study of Aspergillus flavus fungus from uranium mines

    International Nuclear Information System (INIS)

    Cultivation is discussed of fungus strain Aspergillus flavus obtained from materials from uranium mines. It was found that an addition of 0.6 g of uranium in form of uranyl acetate or of 0.6 g of thorium in form on thorium nitrate in 1000 ml of the standard medium had stimulating effects on the growth and sporulation of Aspergillus flavus. Irradiating the cultivated fungus through a polyethylene foil did not show a stimulating effect. It is stated that uranium and its daughters must be directly present in the culture medium for their stimulating effect on growth and sporulation to manifest itself. (H.S.)

  2. New aquatic sites of the fungus Sommerstorffia spinosa

    Directory of Open Access Journals (Sweden)

    Bazyli Czeczuga

    2014-08-01

    Full Text Available When studying zoosporic fungi in the waters of northeastern Poland tbe authors found new sites of a rare fungus - Sommerstorffia spinosa Arnaudow. Its growth was observed in water samples collected from limnologically different reservoirs, from the spring Jaroszówka, the oligotrophic type (Lake Białe, through mesotrophic (Lake Wigry to the polytrophic type (pond Fosa with high content of hydrogen sulphide under ice cover. This fungus was also found in the river Biała, which flowing through Białystok gets polluted by municipal wastes. Moreover, the successive stages of S. spinosa development in the aquatic environment are described.

  3. Patterns of functional enzyme activity in fungus farming ambrosia beetles

    Directory of Open Access Journals (Sweden)

    De Fine Licht Henrik H

    2012-06-01

    Full Text Available Abstract Introduction In wood-dwelling fungus-farming weevils, the so-called ambrosia beetles (Curculionidae: Scolytinae and Platypodinae, wood in the excavated tunnels is used as a medium for cultivating fungi by the combined action of digging larvae (which create more space for the fungi to grow and of adults sowing and pruning the fungus. The beetles are obligately dependent on the fungus that provides essential vitamins, amino acids and sterols. However, to what extent microbial enzymes support fungus farming in ambrosia beetles is unknown. Here we measure (i 13 plant cell-wall degrading enzymes in the fungus garden microbial consortium of the ambrosia beetle Xyleborinus saxesenii, including its primary fungal symbionts, in three compartments of laboratory maintained nests, at different time points after gallery foundation and (ii four specific enzymes that may be either insect or microbially derived in X. saxesenii adult and larval individuals. Results We discovered that the activity of cellulases in ambrosia fungus gardens is relatively small compared to the activities of other cellulolytic enzymes. Enzyme activity in all compartments of the garden was mainly directed towards hemicellulose carbohydrates such as xylan, glucomannan and callose. Hemicellulolytic enzyme activity within the brood chamber increased with gallery age, whereas irrespective of the age of the gallery, the highest overall enzyme activity were detected in the gallery dump material expelled by the beetles. Interestingly endo-β-1,3(4-glucanase activity capable of callose degradation was identified in whole-body extracts of both larvae and adult X. saxesenii, whereas endo-β-1,4-xylanase activity was exclusively detected in larvae. Conclusion Similar to closely related fungi associated with bark beetles in phloem, the microbial symbionts of ambrosia beetles hardly degrade cellulose. Instead, their enzyme activity is directed mainly towards comparatively more easily

  4. Composition of symbiotic bacteria predicts survival in Panamanian golden frogs infected with a lethal fungus

    OpenAIRE

    Matthew H Becker; Walke, Jenifer B.; Cikanek, Shawna; Savage, Anna E.; Mattheus, Nichole; Santiago, Celina N.; Minbiole, Kevin P. C.; Harris, Reid N.; Lisa K Belden; Gratwicke, Brian

    2015-01-01

    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...

  5. Current Situations of Edible Fungus Production in Lianyungang City and Development Countermeasures

    Institute of Scientific and Technical Information of China (English)

    LI Guan-xi; GE Xiong-can; WEI Liang-zhi

    2012-01-01

    On the basis of characteristics of edible fungus production in Lianyungang City, we analyzed its advantages and disadvantages and put forward suggestions and countermeasures for development of edible fungus industry, mainly including strengthening guidance and leadership of government, introducing professional personnel, and developing the edible fungus industry through science and technology.

  6. Towards an integrated understanding of the consequences of fungus domestication on the fungus-growing termite gut microbiota

    DEFF Research Database (Denmark)

    Thomas-Poulsen, Michael

    2015-01-01

    Approximately 30 million years ago (MYA), the subfamily of higher termites Macrotermitinae domesticated a fungus, Termitomyces, as the main plant decomposer and food source for the termite host. The origin of fungiculture shifted the composition of the termite gut microbiota, and some of the...... powerful, particularly if executed in comparative analyses across the well-established congruent termite-fungus phylogenies. This will allow for testing if gut communities have evolved in parallel with their hosts, with implications for our general understanding of the evolution of gut symbiont communities...

  7. Diversity of Andean amphibians of the Tamá National Natural Park in Colombia: a survey for the presence of Batrachochytrium dendrobatidis

    Directory of Open Access Journals (Sweden)

    Acevedo, A. A.

    2016-01-01

    Full Text Available Changes in diversity and possible decreases in populations of amphibians have not yet been determined in many areas in the Andes. This study aimed to develop an inventory of the biodiversity of amphibians in the Andean areas of the Tamá National Natural Park (Tamá NNP and to evaluate the patterns of infection by Batrachochytrium dendrobatidis (Bd in preserved and degraded areas. We performed samplings focused on three habitats (forest, open areas and streams in four localities from 2,000 to 3,200 m in altitude. Fourteen species were recorded, 12 of which were positive for Bd. A total of 541 individuals were diagnosed and 100 were positive. Our analyses showed that preserved areas play an important role in keeping many individuals Bd–free as compared to those in degraded areas. This was the first study to evaluate diversity and infection by Bd in the northeast region of Colombia. Our findings may help improve our knowledge of the diversity of amphibian species in the area and facilitate the implementation of action plans to mitigate the causes associated with the decrease in amphibian populations.

  8. Synergistic inhibition of the lethal fungal pathogen Batrachochytrium dendrobatidis: the combined effect of symbiotic bacterial metabolites and antimicrobial peptides of the frog Rana muscosa.

    Science.gov (United States)

    Myers, Jillian M; Ramsey, Jeremy P; Blackman, Alison L; Nichols, A Elizabeth; Minbiole, Kevin P C; Harris, Reid N

    2012-08-01

    A powerful mechanism for protection against disease in animals is synergy between metabolites present in the natural microbiota of the host and antimicrobial peptides (AMPs) produced by the host. We studied this method of protection in amphibians in regard to the lethal disease chytridiomycosis, which is caused by Batrachochytrium dendrobatidis (Bd). In this study, we show that the AMPs of Rana muscosa, as well as the metabolite 2,4-diacetylphloroglucinol (2,4-DAPG) from Pseudomonas fluorescens, a bacterial species normally found on the skin of R. muscosa, were inhibitory to the growth of Bd in vitro. When both AMPs and 2,4-DAPG were used in growth inhibition assays, they worked synergistically to inhibit the growth of Bd. This synergy resulted in reduced minimum concentrations necessary for inhibition by either 2,4-DAPG or AMPs. This inhibitory concentration of AMPs did not inhibit the growth of a P. fluorescens strain that produced 2,4-DAPG in vitro, although its growth was inhibited at higher peptide concentrations. These data suggest that the AMPs secreted onto frog skin and the metabolites secreted by the resident beneficial bacteria may work synergistically to enhance protection against Bd infection on amphibian skin. These results may aid conservation efforts to augment amphibian skins' resistance to chytridiomycosis by introducing anti-Bd bacterial species that work synergistically with amphibian AMPs. PMID:22914957

  9. Fun Microbiology: How To Measure Growth of a Fungus.

    Science.gov (United States)

    Mitchell, James K.; And Others

    1997-01-01

    Describes an experiment to demonstrate a simple method for measuring fungus growth by monitoring the effect of temperature on the growth of Trichoderma viride. Among the advantages that this experimental model provides is introducing students to the importance of using the computer as a scientific tool for analyzing and presenting data. (AIM)

  10. Genetic variability in the pistachio late blight fungus, Alternaria alternata

    Science.gov (United States)

    Genetic variation in the pistachio late blight fungus, Alternaria alternata, was investigated by restriction fragment length polymorphism (RFLP) in the rDNA region. Southern hybridization of EcoRI, HindIII, and Xbal digested fungal DNA with a RNA probe derived from Alt1, an rDNA clone isolated from ...

  11. Phenolic Compound Utilization by the Soft Rot Fungus Lecythophora hoffmannii

    OpenAIRE

    Bugos, Robert C.; Sutherland, John B.; Adler, John H.

    1988-01-01

    Nine phenolic compounds were metabolized by the soft rot fungus Lecythophora hoffmannii via protocatechuic acid and subsequently cleaved by protocatechuate 3,4-dioxygenase as determined by oxygen uptake, substrate depletion, and ring cleavage analysis. Catechol was metabolized by catechol 1,2-dioxygenase. Fungal utilization of these aromatic compounds may be important in the metabolism of wood decay products.

  12. Identification and characterization of glucoamylase from the fungus, Thermomyces lanuginosus

    DEFF Research Database (Denmark)

    Thorsen, Thor Seneca; Johnsen, Anders; Josefsen, K.; Jensen, Bo

    2006-01-01

    thermophilic fungus Talaromyces emersonii. cDNA encoding Thermomyces lanuginosus glucoamylase was expression cloned into Pichia pastoris, producing approximately 7.4 U/ml. It was concluded that alternative mRNA splicing as it might occur in Aspergillus niger glucoamylase is not responsible for the occurrence...

  13. OXIDATION OF PERSISTANT ENVIRONMENTAL POLLUTANTS BY A WHITE ROT FUNGUS

    Science.gov (United States)

    The white rot fungus Phanerochaete chrysosporium degraded DDT [1,1,-bis(4-chlorophenyl)-2,2,2-trichloroethane], 3,4,3',4'-tetrachlorobiphenyl, 2,4,5,2',-4',5'-hexachlorobiphenyl, 2,3,7,8-tetrachlorodibenzo-p-dioxin, lindane (1,2,3,4,5,6-hexachlorocylohexane), and benzo[a]pyrene t...

  14. Host identity matters in the amphibian-Batrachochytrium dendrobatidis system: fine-scale patterns of variation in responses to a multi-host pathogen.

    Directory of Open Access Journals (Sweden)

    Stephanie Gervasi

    Full Text Available Species composition within ecological assemblages can drive disease dynamics including pathogen invasion, spread, and persistence. In multi-host pathogen systems, interspecific variation in responses to infection creates important context dependency when predicting the outcome of disease. Here, we examine the responses of three sympatric host species to a single fungal pathogen, Batrachochytrium dendrobatidis, which is associated with worldwide amphibian population declines and extinctions. Using an experimental approach, we show that amphibian species from three different genera display significant differences in patterns of pathgen-induced mortality as well as the magnitude and temporal dynamics of infection load. We exposed amphibians to one of four inoculation dose treatments at both larval and post- metamorphic stages and quantified infection load on day 8 and day 15 post-inoculation. Of the three species examined, only one (the Pacific treefrog; Pseudacris regilla displayed "dose-dependent" responses; survival was reduced and infection load was elevated as inoculation dose was increased. We observed a reduction in survival but no differences in infection load across pathogen treatments in Cascades frogs (Rana cascadae. Western toads (Anaxyrus boreas displayed differences in infection load but no differences in survival across pathogen treatments. Within species, responses to the pathogen varied with life history stage, and the most heavily infected species at the larval stage was different from the most heavily infected species at the post-metamorphic stage. Temporal changes in infection load were species and life history stage-specific. We show that variation in susceptibility to this multi-host pathogen is complex when viewed at a fine-scale and may be mediated through intrinsic host traits.

  15. Lactose enhances cellulase production by the filamentous fungus Acremonium cellulolyticus.

    Science.gov (United States)

    Fang, Xu; Yano, Shinichi; Inoue, Hiroyuki; Sawayama, Shigeki

    2008-08-01

    Acremonium cellulolyticus is a fungus that produces cellulase and has been exploited by enzyme industry. To promote cellulase production by A. cellulolyticus strain C-1, we evaluated the effects of the saccharides: Solka Floc (cellulose), soluble soybean polysaccharide (SSPS), pullulan, lactose, trehalose, sophorose, cellobiose, galactose, sorbose, lactobionic acid, and mixtures as carbon sources for cellulase production. Solka Floc with SSPS enhanced cellulase production. Lactose as the sole carbon source induced cellulase synthesis in this fungus, and the synergistic effects between lactose and Solka Floc was observed. Various enzyme activities and the protein composition of crude enzyme produced by cultures with or without addition of lactose were analyzed. The results showed that lactose addition greatly improves the production of various proteins with cellulase activity by A. cellulolyticus. To our knowledge, this is the first report on production of cellulases by lactose in the A. cellulolyticus. PMID:18804052

  16. Mutualistic fungi control crop diversity in fungus-growing ants.

    Science.gov (United States)

    Poulsen, Michael; Boomsma, Jacobus J

    2005-02-01

    Leaf-cutting ants rear clonal fungi for food and transmit the fungi from mother to daughter colonies so that symbiont mixing and conflict, which result from competition between genetically different clones, are avoided. Here we show that despite millions of years of predominantly vertical transmission, the domesticated fungi actively reject mycelial fragments from neighboring colonies, and that the strength of these reactions are in proportion to the overall genetic difference between these symbionts. Fungal incompatibility compounds remain intact during ant digestion, so that fecal droplets, which are used for manuring newly grown fungus, elicit similar hostile reactions when applied to symbionts from other colonies. Symbiont control over new mycelial growth by manurial imprinting prevents the rearing of multiple crops in fungus gardens belonging to the same colony. PMID:15692054

  17. EVOLUTIONARY TRANSITIONS IN ENZYME ACTIVITY OF ANT FUNGUS GARDENS

    DEFF Research Database (Denmark)

    De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G;

    2010-01-01

    an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across...... the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens...... are targeted primarily towards partial degradation of plant cell walls, reflecting a plesiomorphic state of non-domesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major...

  18. Transformation of the mycorrhizal fungus Laccaria bicolor using Agrobacterium tumefaciens.

    Science.gov (United States)

    Kemppainen, Minna J; Pardo, Alejandro G

    2011-01-01

    Most boreal and temperate forest trees form a mutualistic symbiosis with soil borne fungi called ectomycorrhiza (ECM). In this association both partners benefit due to nutrient exchange at the symbiotic interface. Laccaria bicolor is the first mycorrhizal fungus with its genome sequenced thus making possible for the first time to analyze genome scale gene expression profiles of a mutualistic fungus. However, in order to be able to take full advantage of the genome sequence, reverse genetic tools are needed. Among them a high throughput transformation system is crucial. Herein we present a detailed protocol for genetic transformation of L. bicolor by means of Agrobacterium tumefaciens with emphasis on critical steps affecting the success and efficiency of the approach. PMID:21636986

  19. White-nose syndrome fungus (Geomyces destructans) in bats, Europe.

    Science.gov (United States)

    Wibbelt, Gudrun; Kurth, Andreas; Hellmann, David; Weishaar, Manfred; Barlow, Alex; Veith, Michael; Prüger, Julia; Görföl, Tamás; Grosche, Lena; Bontadina, Fabio; Zöphel, Ulrich; Seidl, Hans Peter; Seidl, Hans Peter; Blehert, David S

    2010-08-01

    White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus. PMID:20678317

  20. Extracellular biosynthesis of silver nanoparticles using the fungus Fusarium semitectum

    International Nuclear Information System (INIS)

    Development of environmental friendly procedures for the synthesis of metal nanoparticles through biological processes is evolving into an important branch of nanobiotechnology. In this paper, we report on the use of fungus 'Fusarium semitectum' for the extracellular synthesis of silver nanoparticles from silver nitrate solution (i.e. through the reduction of Ag+ to Ag0). Highly stable and crystalline silver nanoparticles are produced in solution by treating the filtrate of the fungus F. semitectum with the aqueous silver nitrate solution. The formations of nanoparticles are understood from the UV-vis and X-ray diffraction studies. Transmission electron microscopy of the silver particles indicated that they ranged in size from 10 to 60 nm and are mostly spherical in shape. Interestingly the colloidal suspensions of silver nanoparticles are stable for many weeks. Possible medicinal applications of these silver nanoparticles are envisaged

  1. Engineering a filamentous fungus for L-rhamnose extraction.

    Science.gov (United States)

    Kuivanen, Joosu; Richard, Peter

    2016-03-01

    L-Rhamnose is a high value rare sugar that is used as such or after chemical conversions. It is enriched in several biomass fractions such as the pectic polysaccharides rhamnogalacturonan I and II and in naringin, hesperidin, rutin, quercitrin and ulvan. We engineered the filamentous fungus Aspergillus niger to not consume L-rhamnose, while it is still able to produce the enzymes for the hydrolysis of L-rhamnose rich biomass. As a result we present a strain that can be used for the extraction of L-rhamnose in a consolidated process. In the process the biomass is hydrolysed to the monomeric sugars which are consumed by the fungus leaving the L-rhamnose. PMID:27033543

  2. Mutualistic fungi control crop diversity in fungus-growing ants

    DEFF Research Database (Denmark)

    Poulsen, Michael; Boomsma, Jacobus J

    2005-01-01

    Leaf-cutting ants rear clonal fungi for food and transmit the fungi from mother to daughter colonies so that symbiont mixing and conflict, which result from competition between genetically different clones, are avoided. Here we show that despite millions of years of predominantly vertical...... transmission, the domesticated fungi actively reject mycelial fragments from neighboring colonies, and that the strength of these reactions are in proportion to the overall genetic difference between these symbionts. Fungal incompatibility compounds remain intact during ant digestion, so that fecal droplets......, which are used for manuring newly grown fungus, elicit similar hostile reactions when applied to symbionts from other colonies. Symbiont control over new mycelial growth by manurial imprinting prevents the rearing of multiple crops in fungus gardens belonging to the same colony....

  3. White-nose syndrome fungus (Geomyces destructans) in bats, Europe

    Science.gov (United States)

    Wibbelt, G.; Kurth, A.; Hellmann, D.; Weishaar, M.; Barlow, A.; Veith, M.; Pruger, J.; Gorfol, T.; Grosche, T.; Bontadina, F.; Zophel, U.; Seidl, Hans-Peter; Cryan, P.M.; Blehert, D.S.

    2010-01-01

    White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus.

  4. The Identity of a Pea Blight Fungus in South Africa *

    Directory of Open Access Journals (Sweden)

    K. T. van Warmelo

    1966-12-01

    Full Text Available The perfect stage of Ascochyta pinodes (Berk. & Blox. Jones, a cause of pea blight in Natal, was compared with type material of  Sphaeria pinodes Berk, and Blox.,  Mycosphaerella pinodes (Berk. & Blox. Stone, and  Didymella pinodes (Berk. & Blox. Petrak and the development o f its ascocarps studied. Two types of ascocarp were found on the material of  Didymella pinodes, one perithecial and the other ascolocular in structure. The ascocarp of the South African fungus was typically ascolocular in development and construction and similar to that of other species of Mycosphaerella. These ascocarps were identical to those of  Sphaeria pinodes and Mycosphaerella pinodes and the ascolocular ascocarps of the  DidymeUa pinodes material. In development and morphology this fungus agrees more closely with the original generic concepts of the genus Mycosphaerella Joh. than with  Didymella Sacc. and should thus be named Mycosphaerella pinodes (Berk. & Blox. Stone.

  5. Biosorption of cadmium using the fungus Aspergillus niger

    OpenAIRE

    Barros Júnior L.M.; Macedo G.R.; Duarte M.M.L.; Silva E.P.; Lobato A.K.C.L.

    2003-01-01

    Sorption experiments using the Aspergillus niger fungus for cadmium removal were carried out to study the factors influencing and optimizing the biosorption of this metal. The effects of pH, time, biomass concentration, and initial concentration of the heavy metal on the rate of metallic biosorption were examined. An experimental design was also used to determine the values of the under study variables that provided the greatest biosorption efficiency. A technique for biomass recovery was als...

  6. Two New Secondary Metabolites from the Endophytic Fungus Endomelanconiopsis endophytica

    OpenAIRE

    Zhang-Hua Sun; Hao-Hua Li; Fa-Liang Liang; Yu-Chan Chen; Hong-Xin Liu; Sai-Ni Li; Guo-Hui Tan; Wei-Min Zhang

    2016-01-01

    Two new secondary metabolites, endomeketals A–B (1–2), a new natural product (3), and a known compound (4) were isolated from the ethyl acetate extract of the endophytic fungus Endomelanconiopsis endophytica A326 derived from Ficus hirta. Their structures were determined on the basis of extensive spectroscopic analysis. All compounds were evaluated for their cytotoxic activities against SF-268, MCF-7, NCI-H460, and HepG-2 tumor cell lines. However, no compound showed cytotoxic activity agains...

  7. Four Novel Hydropyranoindeno- Derivatives from Marine Fungus Aspergillus versicolor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    From the cultured filtrates of fungus Aspergillus versicolor,isolated from marine sponge Xestospongia exigua,four novel secondary metabolites,namely aspergillone 1,aspergillodiol 2, aspergillol 3 and 12-acetyl-aspergillol 4,have been isolated by column chromatographic separation.The structures of all the new compounds are established on the basis of extensive 2D NMR spectroscopy in conjugation with MS,UV spectral analysis.The basic structure pattern of those compounds possessed an hydroindenoisopyran nucleus.

  8. No sex in fungus-farming ants or their crops

    OpenAIRE

    Himler, Anna G.; Caldera, Eric J.; Baer, Boris C.; Fernández-Marín, Hermógenes; Mueller, Ulrich G.

    2009-01-01

    Asexual reproduction imposes evolutionary handicaps on asexual species, rendering them prone to extinction, because asexual reproduction generates novel genotypes and purges deleterious mutations at lower rates than sexual reproduction. Here, we report the first case of complete asexuality in ants, the fungus-growing ant Mycocepurus smithii, where queens reproduce asexually but workers are sterile, which is doubly enigmatic because the clonal colonies of M. smithii also depend on clonal fungi...

  9. Distribution pattern and maintenance of ectomycorrhizal fungus diversity

    OpenAIRE

    Cheng Gao; Liangdong Guo

    2013-01-01

    Ectomycorrhiza (ECM) are symbionts formed between soil fungi and plant root systems, in which the fungus exchanges soil-derived nutrients for carbohydrates obtained from the host plant. As an important component of terrestrial ecosystems, ECM fungi can play an essential role in biodiversity maintenance and plant community succession. Understanding the distribution pattern and maintenance of ECM fungal diversity is therefore critical to the study of biodiversity and ecosystem functioning. An a...

  10. Evolutionary transitions in enzyme activity of ant fungus gardens

    OpenAIRE

    de Fine Licht, Henrik Hjarvard; Schiøtt, M.; Mueller, U. G.; Boomsma, J.J.

    2010-01-01

    Fungus-growing (attine) ants and their fungal symbionts passed through several evolutionary transitions during their 50 million year old evolutionary history. The basal attine lineages often shifted between two main cultivar clades, whereas the derived higher-attine lineages maintained an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparat...

  11. Complete Genome Sequence of the Endophytic Fungus Diaporthe (Phomopsis) ampelina.

    Science.gov (United States)

    Savitha, J; Bhargavi, S D; Praveen, V K

    2016-01-01

    Diaporthe ampelina was isolated as an endophytic fungus from the root of Commiphora wightii, a medicinal plant collected from Dhanvantri Vana, Bangalore University, Bangalore, India. The whole genome is 59 Mb, contains a total of 905 scaffolds, and has a G+C content of 51.74%. The genome sequence of D. ampelina shows a complete absence of lovastatin (an anticholesterol drug) gene cluster. PMID:27257198

  12. Adaptieve zinktolerantie mechanismen in het ectomycorrhiza fungus Suillus luteus

    OpenAIRE

    VAESEN, Sherwin

    2007-01-01

    Populaties van verschillende biota die blootgesteld worden aan hoge zinkconcentraties ondervinden een sterke selectiedruk. Deze selectiedruk kan tot het ontstaan van zinktolerante populaties leiden, zoals bij de Suillus populaties die goed groeien in de buurt van zinksmelters in Noord-Limburg [1]. De ectomycorrhiza fungus Suillus luteus is een wortelsymbiont die vaak gevonden wordt in met Zn gecontamineerde regio’s en waarvan reeds aangetoond werd dat hij de zware metaaltoxicit...

  13. White-Nose Syndrome Fungus (Geomyces destructans) in Bats, Europe

    OpenAIRE

    Wibbelt, Gudrun; Kurth, Andreas; Hellmann, David; Weishaar, Manfred; Barlow, Alex; Veith, Michael; Prüger, Julia; Görföl, Tamás; Grosche, Lena; Bontadina, Fabio; Zöphel, Ulrich; Seidl, Hans-Peter; Cryan, Paul M.; Blehert, David S.

    2010-01-01

    White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences...

  14. Honey fungus found in the management-plan area Votice

    OpenAIRE

    Holá, Jana

    2014-01-01

    The object of this bachelor work is a study of the common mushroom pest honey fungus (genus Armillaria). The main interest is dedicated to A.ostoyae and its meaning in the forestry on the LHC Votice region. Occurrence of honey fungi and the percentage of its attacks in relation to weather conditions (especially influence of drought) was studied on defined permanent study plots. Simultaneously, monitoring of these fungi occurrence outside the permanent plots in a plan choosing where indiv...

  15. Methods for Mutation and Selection of the Ergot Fungus

    OpenAIRE

    Srikrai, Suthinee; Robbers, James E.

    1983-01-01

    A new method is described in which the Salkowski reaction is used for the rapid selection of alkaloid-producing mutants of the ergot fungus. This method was used to investigate the influence of a second mutation with N-methyl-N′-nitro-N-nitrosoguanidine (NTG) on various mutants selected by a preliminary NTG mutation of Claviceps sp. strain SD 58. Three groups of mutants were used: high alkaloid producers, low alkaloid producers, and auxotrophs. Results indicated that a second mutation of all ...

  16. Complete Genome Sequence of the Endophytic Fungus Diaporthe (Phomopsis) ampelina

    Science.gov (United States)

    Bhargavi, S. D.; Praveen, V. K.

    2016-01-01

    Diaporthe ampelina was isolated as an endophytic fungus from the root of Commiphora wightii, a medicinal plant collected from Dhanvantri Vana, Bangalore University, Bangalore, India. The whole genome is 59 Mb, contains a total of 905 scaffolds, and has a G+C content of 51.74%. The genome sequence of D. ampelina shows a complete absence of lovastatin (an anticholesterol drug) gene cluster. PMID:27257198

  17. Chemically armed mercenary ants protect fungus-farming societies

    OpenAIRE

    Adams, R. M. M.; Liberti, J.; Illum, A. A.; Jones, T H; Nash, D R; Boomsma, J.J.

    2013-01-01

    We document the behavioral interactions among three ant species: a fungus-growing host ant, a permanently associated parasitic guest ant, and a raiding agro-predator ant. We show that the presence of guest ants becomes advantageous when host ants are attacked by raider ants, because guest ants use alkaloid venom to defend their host ant colony. Furthermore, detection of the guest ant odors is sufficient to discourage raider scouts from recruiting nestmates to host colonies. Guest ants likely ...

  18. Pathogenic Fungus Microsporum canis Activates the NLRP3 Inflammasome

    OpenAIRE

    Mao, Liming; Zhang, Liping; Li, Hua; Chen, Wei; Wang, Hongbin; Wu, Shuxian; Guo, Caiqin; Lu, Ailing; Yang, Guiwen; An, Liguo; Abliz, Paride; Meng, Guangxun

    2014-01-01

    Microsporum canis is a pathogenic fungus with worldwide distribution that causes tinea capitis in animals and humans. M. canis also causes invasive infection in immunocompromised patients. To defy pathogenic fungal infection, the host innate immune system is the first line of defense. As an important arm of innate immunity, the inflammasomes are intracellular multiprotein complexes that control the activation of caspase-1, which cleaves proinflammatory cytokine pro-interleukin-1β (IL-1β) into...

  19. Fungus mediated synthesis of biomedically important cerium oxide nanoparticles

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • First time biological synthesis of cerium oxide oxide nanoparticles using fungus Humicola sp. • Complete characterization of cerium oxide nanoparticles. • Biosynthesis of naturally protein capped, luminescent and water dispersible CeO2 nanoparticles. • Biosynthesized CeO2 nanoparticles can be used for many biomedical applications. - Abstract: Nanomaterials can be synthesized by chemical, physical and the more recently discovered biological routes. The biological routes are advantageous over the chemical and physical ones as unlike these, the biological synthesis protocols occur at ambient conditions, are cheap, non-toxic and eco-friendly. Although purely biological and bioinspired methods for the synthesis of nanomaterials are environmentally benign and energy conserving processes, their true potential has not been explored yet and attempts are being made to extend the formation of technologically important nanoparticles using microorganisms like fungi. Though there have been reports on the biosynthesis of oxide nanoparticles by our group in the past, no attempts have been made to employ fungi for the synthesis of nanoparticles of rare earth metals or lanthanides. Here we report for the first time, the bio-inspired synthesis of biomedically important cerium oxide (CeO2) nanoparticles using the thermophilic fungus Humicola sp. The fungus Humicola sp. when exposed to aqueous solutions of oxide precursor cerium (III) nitrate hexahydrate (CeN3O9·6H2O) results in the extracellular formation of CeO2 nanoparticles containing Ce (III) and Ce (IV) mixed oxidation states, confirmed by X-ray Photoemission Spectroscopy (XPS). The formed nanoparticles are naturally capped by proteins secreted by the fungus and thus do not agglomerate, are highly stable, water dispersible and are highly fluorescent as well. The biosynthesized nanoparticles were characterized by UV–vis spectroscopy, Photoluminescence spectroscopy (PL), Transmission

  20. Lasiodiplodins from mangrove endophytic fungus Lasiodiplodia sp. 318.

    Science.gov (United States)

    Li, Jing; Xue, Yanyu; Yuan, Jie; Lu, Yongjun; Zhu, Xun; Lin, Yongcheng; Liu, Lan

    2016-04-01

    Four new lasiodiplodins (1-4), together with three known analogues, have been isolated from a mangrove endophytic fungus, Lasiodiplodia sp. 318#. Their structures were elucidated by spectroscopic techniques. Cytotoxic activities of compounds 1-7 were evaluated in vitro against human cancer lines THP1, MDA-MB-435, A549, HepG2 and HCT-116. Compound 4 exhibited moderate cytotoxic activities. PMID:26222141

  1. Efficient xylose fermentation by the brown rot fungus Neolentinus lepideus.

    Science.gov (United States)

    Okamoto, Kenji; Kanawaku, Ryuichi; Masumoto, Masaru; Yanase, Hideshi

    2012-02-10

    The efficient production of bioethanol on an industrial scale requires the use of renewable lignocellulosic biomass as a starting material. A limiting factor in developing efficient processes is identifying microorganisms that are able to effectively ferment xylose, the major pentose sugar found in hemicellulose, and break down carbohydrate polymers without pre-treatment steps. Here, a basidiomycete brown rot fungus was isolated as a new biocatalyst with unprecedented fermentability, as it was capable of converting not only the 6-carbon sugars constituting cellulose, but also the major 5-carbon sugar xylose in hemicelluloses, to ethanol. The fungus was identified as Neolentinus lepideus and was capable of assimilating and fermenting xylose to ethanol in yields of 0.30, 0.33, and 0.34 g of ethanol per g of xylose consumed under aerobic, oxygen-limited, and anaerobic conditions, respectively. A small amount of xylitol was detected as the major by-product of xylose metabolism. N. lepideus produced ethanol from glucose, mannose, galactose, cellobiose, maltose, and lactose with yields ranging from 0.34 to 0.38 g ethanol per g sugar consumed, and also exhibited relatively favorable conversion of non-pretreated starch, xylan, and wheat bran. These results suggest that N. lepideus is a promising candidate for cost-effective and environmentally friendly ethanol production from lignocellulosic biomass. To our knowledge, this is the first report on efficient ethanol fermentation from various carbohydrates, including xylose, by a naturally occurring brown rot fungus. PMID:22226194

  2. The infrabuccal pellet piles of fungus-growing ants.

    Science.gov (United States)

    Little, Ainslie E F; Murakami, Takahiro; Mueller, Ulrich G; Currie, Cameron R

    2003-12-01

    Fungus-growing ants (Attini) live in an obligate mutualism with the fungi they cultivate for food. Because of the obligate nature of this relationship, the success of the ants is directly dependent on their ability to grow healthy fungus gardens. Attine ants have evolved complex disease management strategies to reduce their garden's exposure to potential parasitic microbes, to prevent the establishment of infection in their gardens, and to remove infected garden sections. The infrabuccal pocket, a filtering device located in the oral cavity of all ants, is an integral part of the mechanisms that leaf-cutter ants use to prevent the invasion and spread of general microbial parasites and the specific fungal-garden parasite Escovopsis. Fungus-growing ants carefully groom their garden, collecting general debris and pathogenic spores of Escovopsis in their infrabuccal pocket, the contents of which are later expelled in dump chambers inside the nest or externally. In this study we examined how a phylogenetically diverse collection of attine ants treat their infrabuccal pellets. Unlike leaf-cutters that deposit their infrabuccal pellets directly in refuse piles, ants of the more basal attine lineages stack their infrabuccal pellets in piles located close to their gardens, and a separate caste of workers is devoted to the construction, management, and eventual disposal of these piles. PMID:14676952

  3. Relationships between Swiss needle cast and ectomycorrhizal fungus diversity.

    Science.gov (United States)

    Luoma, Daniel L; Eberhart, Joyce L

    2014-01-01

    Swiss needle cast (SNC) is a disease specific to Douglas-fir (Pseudotsuga menziesii) caused by the ascomycete Phaeocryptopus gaeumannii. Here we examine characteristics of the EM fungus community that are potentially useful in predictive models that would monitor forest health. We found that mean EM density (number of colonized root tips/soil core) varied nearly 10-fold among sites of varying levels of SNC, while mean EM fungus species richness (number of species/soil core) varied by about 2.5 times. Strong relationships were found between EM and SNC parameters: EM species richness was positively correlated with both Douglas-fir needle retention (R(2) = 0.93) and EM density (R(2) = 0.65); EM density also was significantly correlated with Douglas-fir needle retention (R(2) = 0.70). These simple characteristics of the EM fungus community could be used to monitor forest health and generate predictive models of site suitability for Douglas-fir. Based on previous findings that normally common EM types were reduced in frequency on sites with severe SNC, we also hypothesized that some EM fungi would be stress tolerant-dominant species. Instead, we found that various fungi were able to form EM with the stressed trees, but none were consistently dominant across samples in the severely diseased areas. PMID:24895426

  4. Dev konka bülloza içinde fungus topu: Olgu sunumu,

    OpenAIRE

    Acar, A.; Uyar, M; Açıkalın, A.; E.Dursun; , S.Kurukahvecioğlu; Eryılmaz, A.

    2013-01-01

    Concha bullosa is one of the most common nasal anatomic variations. The size of concha bullosa is important factor in its symptomatic situation. Fungus ball is extramucosal and noninvasive accumulations of degenerating fungal hyphae. It is most common occur form in fungal sinusitis. The fungus ball is mostly caused by Aspergillus spp. In this case report, we present a rare fungus ball case which is localized chonca bullosa. Eight-teen years-old female patient was admitted to our clinic. She h...

  5. Isolated fungal promoters and gene transcription terminators and methods of protein and chemical production in a fungus

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Ziyu; Lasure, Linda L; Magnuson, Jon K

    2014-05-27

    The present invention encompasses isolated gene regulatory elements and gene transcription terminators that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention also encompasses a method of utilizing a fungus for protein or chemical production. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to another molecule comprising a coding region of a gene of interest. The gene regulatory element and gene transcription terminator may temporally and spatially regulate expression of particular genes for optimum production of compounds of interest in a transgenic fungus.

  6. Isolated fungal promoters and gene transcription terminators and methods of protein and chemical production in a fungus

    Science.gov (United States)

    Dai, Ziyu; Lasure, Linda L.; Magnuson, Jon K.

    2008-11-11

    The present invention encompasses isolated gene regulatory elements and gene transcription terminators that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention also encompasses a method of utilizing a fungus for protein or chemical production. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to another molecule comprising a coding region of a gene of interest. The gene regulatory element and gene transcription terminator may temporally and spatially regulate expression of particular genes for optimum production of compounds of interest in a transgenic fungus.

  7. Disease and thermal acclimation in a more variable and unpredictable climate

    Science.gov (United States)

    Raffel, Thomas R.; Romansic, John M.; Halstead, Neal T.; McMahon, Taegan A.; Venesky, Matthew D.; Rohr, Jason R.

    2013-02-01

    Global climate change is shifting the distribution of infectious diseases of humans and wildlife with potential adverse consequences for disease control. As well as increasing mean temperatures, climate change is expected to increase climate variability, making climate less predictable. However, few empirical or theoretical studies have considered the effects of climate variability or predictability on disease, despite it being likely that hosts and parasites will have differential responses to climatic shifts. Here we present a theoretical framework for how temperature variation and its predictability influence disease risk by affecting host and parasite acclimation responses. Laboratory experiments conducted in 80 independent incubators, and field data on disease-associated frog declines in Latin America, support the framework and provide evidence that unpredictable temperature fluctuations, on both monthly and diurnal timescales, decrease frog resistance to the pathogenic chytrid fungus Batrachochytrium dendrobatidis. Furthermore, the pattern of temperature-dependent growth of the fungus on frogs was opposite to the pattern of growth in culture, emphasizing the importance of accounting for the host-parasite interaction when predicting climate-dependent disease dynamics. If similar acclimation responses influence other host-parasite systems, as seems likely, then present models, which generally ignore small-scale temporal variability in climate, might provide poor predictions for climate effects on disease.

  8. Disease in a more variable and unpredictable climate

    Science.gov (United States)

    McMahon, T. A.; Raffel, T.; Rohr, J. R.; Halstead, N.; Venesky, M.; Romansic, J.

    2014-12-01

    Global climate change is shifting the dynamics of infectious diseases of humans and wildlife with potential adverse consequences for disease control. Despite this, the role of global climate change in the decline of biodiversity and the emergence of infectious diseases remains controversial. Climate change is expected to increase climate variability in addition to increasing mean temperatures, making climate less predictable. However, few empirical or theoretical studies have considered the effects of climate variability or predictability on disease, despite it being likely that hosts and parasites will have differential responses to climatic shifts. Here we present a theoretical framework for how temperature variation and its predictability influence disease risk by affecting host and parasite acclimation responses. Laboratory experiments and field data on disease-associated frog declines in Latin America support this framework and provide evidence that unpredictable temperature fluctuations, on both monthly and diurnal timescales, decrease frog resistance to the pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd). Furthermore, the pattern of temperature-dependent growth of the fungus on frogs was inconsistent with the pattern of Bd growth in culture, emphasizing the importance of accounting for the host-parasite interaction when predicting climate-dependent disease dynamics. Consistent with our laboratory experiments, increased regional temperature variability associated with global El Niño climatic events was the best predictor of widespread amphibian losses in the genus Atelopus. Thus, incorporating the effects of small-scale temporal variability in climate can greatly improve our ability to predict the effects of climate change on disease.

  9. Studies on biosorption of nickel using immobilized fungus, Rhizomucor tauricus

    OpenAIRE

    K. Kishore Kumar; M. Krishna Prasad; B. Sarada; Ch. V. R. Murthy

    2012-01-01

    Rhizomucor tauricus, an industrial fungus, was immobilized in sodium alginate and used as adsorbent for the removal of nickel from aqueous solutions. The biosorption capacity of Ni(II) was found to be 394 mg/g of immobilized biomass. It was observed that an increase in pH from 3 to 6 increased the percent adsorption, and an increase in liquid-to-solid ratio from 2 to 10 increased the metal uptake. The percent adsorption was increased when increasing the initial metal concentration from 25 to ...

  10. Polyoxygenated methyl cyclohexanoids from a terrestrial ampelomyces fungus.

    Science.gov (United States)

    Zhang, Huiye; Xue, Jinghua; Wu, Ping; Xu, Liangxiong; Xie, Haihui; Wei, Xiaoyi

    2009-02-27

    Seven structurally related new polyoxygenated methyl cyclohexanoids, ampelomins A-G (1-7), were isolated from the mycelial solid culture of a soil-derived Ampelomyces fungus. Their structures were determined by spectroscopic and chemical means. Ampelomins A (1), C (3), E (5), and G (7) exhibited weak activity against alpha-glucosidase with IC(50) values of 1.74-5.93 mM, and ampelomin A (1) showed moderate antibacterial activity with MIC(90) values ranging from 202.4 to 1015.9 microM. A plausible polyketide biogenetic pathway is postulated for these compounds. PMID:19193024

  11. Cultivation of tea fungus on malt extract medium

    Directory of Open Access Journals (Sweden)

    Cvetković Dragoljub D.

    2002-01-01

    Full Text Available The possibility of application of malt extract as a source of carbohydrate in a medium for tea fungus was investigated. The beverage obtained on such medium was compared with that prepared in a traditional way with sucrose medium. The presence of easily adoptable sugars, glucose and fructose, as dominant in malt medium results in a very effective fermentation, which gives much more sour beverage for the same time and makes it possible to reduce the fermentation period. The obtained beverage has satisfactory sensorial characteristics.

  12. Anti-Mycobacterium tuberculosis activity of fungus Phomopsis stipata

    Directory of Open Access Journals (Sweden)

    Karina Andrade de Prince

    2012-03-01

    Full Text Available Our purpose was to determine the anti-Mycobacterium tuberculosis activity of the metabolites produced by the endophitic fungus Phomopsis stipata (Lib. B. Sutton, (Diaporthaceae, cultivated in different media. The antimycobacterial activity was assessed through the Resazurin Microtiter Assay (REMA and the cytotoxicity test performed on macrophage cell line. The extracts derived from fungi grown on Corn Medium and Potato Dextrose Broth presented the smallest values of Minimum Inhibitory Concentration (MIC and low cytotoxicity, which implies a high selectivity index. This is the first report on the chemical composition and antitubercular activity of metabolites of P. stipata, as well as the influence of culture medium on these properties.

  13. Elemental variations in the germinating fungus Phytophthora palmivora

    Energy Technology Data Exchange (ETDEWEB)

    Mazzolini, A.P.; Sealock, R.M.; Legge, G.J.F. (Micro Analytical Research Centre, Univ. of Melbourne, Parkville (Australia)); Grant, B.R. (Biochemistry Dept., Univ. of Melbourne, Parkville (Australia))

    1991-03-01

    We have measured the elemental variations between zoospores and germinating cystospores of the fungus Phytophthora palmivora, using a scanning proton microprobe. Averaged over a number of individual cells, our results indicate that the level of Ca is much lower in germinating cystospores than in zoospores. The levels of S, Cl, and Zn also appear to be lower, and the level of K appears to be higher. The spatial distribution of elements within the germinating cystospore is very similar for P, S, Cl, K, Mn, Fe, and Cu, but significantly different for Ca and Zn. (orig.).

  14. Elemental variations in the germinating fungus Phytophthora palmivora

    Science.gov (United States)

    Mazzolini, A. P.; Grant, B. R.; Sealock, R. M.; Legge, G. J. F.

    1991-03-01

    We have measured the elemental variations between zoospores and germinating cystospores of the fungus Phytophthora palmivora, using a scanning proton microprobe. Averaged over a number of individual cells, our results indicate that the level of Ca is much lower in germinating cystospores than in zoospores. The levels of S, Cl, and Zn also appear to be lower, and the level of K appears to be higher. The spatial distribution of elements within the germinating cystospore is very similar for P, S, Cl, K, Mn, Fe, and Cu, but significantly different for Ca and Zn.

  15. Elemental variations in the germinating fungus Phytophthora palmivora

    International Nuclear Information System (INIS)

    We have measured the elemental variations between zoospores and germinating cystospores of the fungus Phytophthora palmivora, using a scanning proton microprobe. Averaged over a number of individual cells, our results indicate that the level of Ca is much lower in germinating cystospores than in zoospores. The levels of S, Cl, and Zn also appear to be lower, and the level of K appears to be higher. The spatial distribution of elements within the germinating cystospore is very similar for P, S, Cl, K, Mn, Fe, and Cu, but significantly different for Ca and Zn. (orig.)

  16. Metabolism of p-Cresol by the Fungus Aspergillus fumigatus

    OpenAIRE

    Jones, Kerina H.; Trudgill, Peter W.; Hopper, David J.

    1993-01-01

    The fungus Aspergillus fumigatus ATCC 28282 was shown to grow on p-cresol as its sole source of carbon and energy. A pathway for metabolism of this compound was proposed. This has protocatechuate as the ring-fission substrate with cleavage and metabolism by an ortho-fission pathway. The protocatechuate was formed by two alternative routes, either by initial attack on the methyl group, which is oxidized to carboxyl, followed by ring-hydroxylation, or by ring-hydroxylation as the first step wit...

  17. Engineering a filamentous fungus for l-rhamnose extraction

    OpenAIRE

    Kuivanen, Joosu; Richard, Peter

    2016-01-01

    l-Rhamnose is a high value rare sugar that is used as such or after chemical conversions. It is enriched in several biomass fractions such as the pectic polysaccharides rhamnogalacturonan I and II and in naringin, hesperidin, rutin, quercitrin and ulvan. We engineered the filamentous fungus Aspergillus niger to not consume l-rhamnose, while it is still able to produce the enzymes for the hydrolysis of l-rhamnose rich biomass. As a result we present a strain that can be used for the extraction...

  18. Bioactive compounds from the endophytic fungus Fusarium proliferatum.

    Science.gov (United States)

    Dame, Zerihun T; Silima, Beauty; Gryzenhout, Marieka; van Ree, Teunis

    2016-06-01

    The crude extract of an endophytic fungus isolated from Syzygium cordatum and identified as Fusarium proliferatum showed 100% cytotoxicity against the brine shrimp Artemia salina at 100 μg/mL. Seven coloured, biologically active metabolites - including ergosta-5,7,22-trien-3β-ol, nectriafurone-8-methyl ether, 9-O-methyl fusarubin, bostrycoidin, bostrycoidin-9-methyl ether and 8-hydroxy-5,6-dimethoxy-2-methyl-3-(2-oxo-propyl)-1,4-naphthoquinone- were isolated from the extract. PMID:26158312

  19. The role of enzymes in fungus-growing ant evolution

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard

    behaviour. Here we report the first large-scale comparative study on fungus garden enzyme profiles and show that various interesting changes can be documented. A more detailed analysis of laccase expression, an enzyme that is believed to oxidize phenols in defensive secondary plant compounds such as tannins......, showed that this enzyme is exclusively found in the gardens of leaf-cutting ants, where it is significantly upregulated in the gongylidia. I’ll discuss the possible role of this enzyme and other fungal modifications in the evolution of the leafcutter ants and their non-leafcutting attine relatives....

  20. BIODEGRADATION OF ENVIRONMENTAL POLLUTANTS BY THE WHITE ROT FUNGUS PHANEROCHAETE CHRYSOPORIUM: INVOLVEMENT OF THE LIGNIN DEGRADING SYSTEM

    Science.gov (United States)

    The white-rot fungus Phanrochaete chrysosporium has the ability to degrade a wide variety of structurally diverse organic compounds, including a number of environmentally persistent organopollutants. The unique biodegradative abilities of this fungus appears to be depend...

  1. BIODEGRADATION OF ENVIRONMENTAL POLLUTANTS BY THE WHITE ROT FUNGUS PHANEROCHATETE CHRYSOSPORIUM: INVOLVEMENT OF THE LIGNIN DEGRADING SYSTEM

    Science.gov (United States)

    The white-rot fungus Phanerochaete chrysosporium has the ability to degrade's wide variety of structurally diverse organic compounds, including a number of environmentall3 persistent organopollutants. he unique biodegradative abilities of this fungus appears to be dependent upon ...

  2. Vertical transmission as the key to the colonization of Madagascar by fungus-growing termites?

    NARCIS (Netherlands)

    Nobre, T.; Eggleton, P.; Aanen, D.K.

    2010-01-01

    The mutualism between fungus-growing termites (Macrotermitinae) and their mutualistic fungi (Termitomyces) began in Africa. The fungus-growing termites have secondarily colonized Madagascar and only a subset of the genera found in Africa is found on this isolated island. Successful long-distance col

  3. Unraveling the Secondary Metabolism of the Biotechnological Important Filamentous Fungus Trichoderma reesei ( Teleomorph Hypocrea jecorina)

    DEFF Research Database (Denmark)

    Jørgensen, Mikael Skaanning

    The filamentous fungus Trichoderma reesei (teleomorph Hypocrea jecorina) is one of the most important industrial production organisms, owing to its highly efficient (hemi-)cellulase synthesis and secretion machineries. These enzymes, which in nature allow the fungus to utilize energy bound in...

  4. First localities in Poland of the recently described fungus Cordyceps bifusispora

    Directory of Open Access Journals (Sweden)

    Anna Bujakiewicz

    2014-08-01

    Full Text Available Two localities of the entomopathogenic fungus Cordyceps bifusispora, hitherto not reported from Poland, are characterised by their site conditions and co-occurring macrofungi during the period of the appearance of its stromata. Description of this fungus culture is given and some remarks on the resemblance of its teleomorphs and anamorphs from different collections are discussed.

  5. Co-evolution of enzyme function in the attine ant-fungus symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    have small nests with a fungus garden the size of a table-tennis ball. Only the leaf-cutting ants are specialized on using fresh leaves as substrate for their fungus gardens, whereas the more basal attine genera use substrates such as dry plant material (leaf litter and small twigs) and also insect...

  6. Amphibian chytridiomycosis: a review with focus on fungus-host interactions.

    Science.gov (United States)

    Van Rooij, Pascale; Martel, An; Haesebrouck, Freddy; Pasmans, Frank

    2015-01-01

    Amphibian declines and extinctions are emblematic for the current sixth mass extinction event. Infectious drivers of these declines include the recently emerged fungal pathogens Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans (Chytridiomycota). The skin disease caused by these fungi is named chytridiomycosis and affects the vital function of amphibian skin. Not all amphibians respond equally to infection and host responses might range from resistant, over tolerant to susceptible. The clinical outcome of infection is highly dependent on the amphibian host, the fungal virulence and environmental determinants. B. dendrobatidis infects the skin of a large range of anurans, urodeles and caecilians, whereas to date the host range of B. salamandrivorans seems limited to urodeles. So far, the epidemic of B. dendrobatidis is mainly limited to Australian, neotropical, South European and West American amphibians, while for B. salamandrivorans it is limited to European salamanders. Other striking differences between both fungi include gross pathology and thermal preferences. With this review we aim to provide the reader with a state-of-the art of host-pathogen interactions for both fungi, in which new data pertaining to the interaction of B. dendrobatidis and B. salamandrivorans with the host's skin are integrated. Furthermore, we pinpoint areas in which more detailed studies are necessary or which have not received the attention they merit. PMID:26607488

  7. Interaction of Rhizobium sp. with Toxin-Producing Fungus in Culture Medium and in a Tropical Soil †

    OpenAIRE

    Habte, Mitiku; Barrion, Melinda

    1984-01-01

    Experiments were conducted to determine the influence of a toxin-producing fungus on a rhizobial population in yeast-mannitol medium and in a tropical soil. The fungus, which was isolated from a highly weathered soil (Tropeptic Eutrustox), was identified as a Metarhizum sp. The density of rhizobial populations established in yeast-mannitol medium in the absence of the fungus was 105 times higher than that established in its presence. However, the fungus did not exert similar antagonistic infl...

  8. Insect symbioses: a case study of past, present, and future fungus-growing ant research

    DEFF Research Database (Denmark)

    Caldera, Eric J; Poulsen, Michael; Suen, Garret;

    2009-01-01

    Fungus-growing ants (Attini: Formicidae) engage in an obligate mutualism with fungi they cultivate for food. Although biologists have been fascinated with fungus-growing ants since the resurgence of natural history in the modern era, the early stages of research focused mainly on the foraging......'s fungus garden, antibiotic-producing actinobacteria that help protect the fungus garden from the parasite, and a black yeast that parasitizes the ant-actinobacteria mutualism. The fungus-growing ant symbiosis serves as a particularly useful model system for studying insect-microbe symbioses, because, to...... date, it contains four well-characterized microbial symbionts, including mutualists and parasites that encompass micro-fungi, macro-fungi, yeasts, and bacteria. Here, we discuss approaches for studying insect-microbe symbioses, using the attine ant-microbial symbiosis as our framework. We draw...

  9. Homoharringtonine production by endophytic fungus isolated from Cephalotaxus hainanensis Li.

    Science.gov (United States)

    Hu, Xiaoping; Li, Wu; Yuan, Mu; Li, Congfa; Liu, Sixin; Jiang, Chunjie; Wu, Yanchun; Cai, Kun; Liu, Yan

    2016-07-01

    Homoharringtonine (HHT), a natural plant alkaloid derived from Cephalotaxus, has demonstrated to have a broad antitumor activity and efficacy in treating human chronic myeloid leukemia. An alternative source is required to substitute for the slow-growing and scarce Cephalotaxus to meet the increasing demand of the drug market. The objective of this study was to screen HHT-producing endophytic fungi from Cephalotaxus hainanensis Li. By screening 213 fungal isolates obtained from the bark parts of Cephalotaxus hainanensis Li, one isolate was found to be capable of biosynthesizing HHT. The fungus was identified as Alternaria tenuissima by morphological characteristics and internal transcribed spacer (ITS) sequence analysis and was named as CH1307. HHT obtained from CH1307 was analyzed through the HPLC and LC-MS/MS and NMR spectroscopy. The extract of the fermentation broth of CH1307 showed antiproliferative activities against K562 (chronic myelocytic leukemia), NB4 (acute promyelocytic leukemia), and HL-60 (promyelocytic leukemia) human cancer cell lines with IC50 values of 67.25 ± 4.26, 65.02 ± 4.75, and 99.23 ± 4.26 μg/mL, respectively. The findings suggest that HHT-producing endophytic fungus, Alternaria tenuissima CH1307 might provide a promising source for the research and application of HHT. PMID:27263005

  10. Antimicrobial chemical constituents from endophytic fungus Phoma sp.

    Institute of Scientific and Technical Information of China (English)

    Hidayat; Hussain; Ines; Kock; Ahmed; Al-Harrasi; Ahmed; Al-Rawahi; Ghulam; Abbas; Ivan; R.Green; Afzal; Shah; Amin; Badshah; Muhammad; Saleem; Siegfried; Draeger; Barbara; Schulz; Karsten; Krohn

    2014-01-01

    Objective:To evaluate the antiniicrobial polenlial of different extracts of the endophytic fungus Phoma sp.and the tentative identification of their active constituents.Methods:The extract and compounds were screened for antimicrobial activity using the Agar Well Diffusion Method.Four compounds were purified using column chromatography and tlieir structures were assigned using~1H and~(13)C NMR spectra,DEPT,2D COSY,HMQC and HMBC experiments.Results:The ethyl acetate fraction of Phoma sp.showed good antifungal,antibacterial,and algicidal properties.One new dihydrofuran derivative,named phomafuranol(1),together with tliree known compounds,phomalacton(2),(3R)-5-hydroxymellein(3)and emodin(4)were isolated from the ethyl acetate fraction of Phoma sp.Preliminary studies indicated that phomalacton(2)displayed strong antibacterial,good antifungal and antialgal activities.Similarly(3R)-5-hydroxymellein(3)and emodin(4)showed good antifungal,antibacterial and algicidal properties.Conclusions:Antimicrobial activities of the ethyl acetate fraction of the endophytic fungus Phoma sp.and isolated compounds clearly demonstrate that Phoma sp.and its active compounds represent a great potential for the food,cosmetic and pharmaceutical industries.

  11. No sex in fungus-farming ants or their crops.

    Science.gov (United States)

    Himler, Anna G; Caldera, Eric J; Baer, Boris C; Fernández-Marín, Hermógenes; Mueller, Ulrich G

    2009-07-22

    Asexual reproduction imposes evolutionary handicaps on asexual species, rendering them prone to extinction, because asexual reproduction generates novel genotypes and purges deleterious mutations at lower rates than sexual reproduction. Here, we report the first case of complete asexuality in ants, the fungus-growing ant Mycocepurus smithii, where queens reproduce asexually but workers are sterile, which is doubly enigmatic because the clonal colonies of M. smithii also depend on clonal fungi for food. Degenerate female mating anatomy, extensive field and laboratory surveys, and DNA fingerprinting implicate complete asexuality in this widespread ant species. Maternally inherited bacteria (e.g. Wolbachia, Cardinium) and the fungal cultivars can be ruled out as agents inducing asexuality. M. smithii societies of clonal females provide a unique system to test theories of parent-offspring conflict and reproductive policing in social insects. Asexuality of both ant farmer and fungal crop challenges traditional views proposing that sexual farmer ants outpace coevolving sexual crop pathogens, and thus compensate for vulnerabilities of their asexual crops. Either the double asexuality of both farmer and crop may permit the host to fully exploit advantages of asexuality for unknown reasons or frequent switching between crops (symbiont reassociation) generates novel ant-fungus combinations, which may compensate for any evolutionary handicaps of asexuality in M. smithii. PMID:19369264

  12. Isolation and Identification of Glucoamylase Producer Fungus from Sago Hampas

    Directory of Open Access Journals (Sweden)

    Alfi Asben

    2013-01-01

    Full Text Available Waste of sago processing, notably hampas (ela still contains sago starch is waste that has not been utilized optimally yet  and causing pollution. Isolation and identification of glucoamylase producer fungus of sago hampas waste  were aims to obtain isolates that have gluco-amylolytic properties, and to know glucoamylase activity of selected fungus isolates after grown on artificial medium.  Indegeneous isolates that can produced glucoamylase will be use to get sugar hidrolysate from starch of sago hampas waste for bioetanol production. The study was conducted with the following stages: 1Take the sample from the tennis, 2 Isolation and Identification, 3 Characterization (clear zone, and 4 The production of glucoamylase from selected isolates, The results obtained are: 1 Isolation of fungi gluco-amylolytic from 2 sources sago hampas were produced 10 isolates. Ten isolates were divided into 4 genuses: Gliocladium (as dominant isolate, Aspergilus, Rizhopus and Geotrichum. Isolates of Gliocladium KE gaves the largest degradation of starch on PDA-Starch medium (clear zone, and followed by isolates of Aspergillus GA; 2 Production of glucoamylase on sago hampas with modificated Danial medium (1992 gave the highest activity of Gliocladium KE   on the fifth day of incubation, namely: 10.72 U / mL of crude enzyme   from the supernatant of fermentation substrate (S, and 17.16 U / mL for crude enzyme from the extract of isopropanol isolation (E.

  13. MORPHOLOGICAL CHARACTERIZATION AND MASS PRODUCTION OF NEMATOPHAGOUS FUNGUS NEMATOCTONUS ROBUSTUS

    Directory of Open Access Journals (Sweden)

    Ramesh babu S,

    2014-06-01

    Full Text Available The plant parasitic nematodes infect the root tissues of the plant causing root galls that lead to reduced water and mineral uptake in the plant root system. Nematophagous fungus are used as biocontrol for the nematodes. Among those Nematoctonus are one of the species used as bioagent. Nematoctonus species produces an extensive mycelium and capture many nematodes with hour glass shaped adhesive knobs on the hyphae. Nematodes become attached to these adhesive knobs and the cuticle of nematode is penetrated by the infective hyphae. This isolate of Nematoctonus robustus is characterized by hyaline mycelium, dikaryotic in nature containing genetically two different nuclei in each cell, having distinct clamp connection. The fungus has better colonizing ability on natural solid substrates like wheat straw and rice straw. It also show good ability to colonize on different cereal grains and various other waste products like coconut coir and FYM etc. This species is one of the best used for mass production and effective for control of plant parasitic nematodes.

  14. Accumulation and chemical states of radiocesium by fungus Saccharomyces cerevisiae

    Science.gov (United States)

    Ohnuki, Toshihiko; Sakamoto, Fuminori; Kozai, Naofumi; Yamasaki, Shinya; Yu, Qianqian

    2014-05-01

    After accident of Fukushima Daiichi Nuclear Power Plant, the fall-out radiocesium was deposited on the ground. Filamentous fungus is known to accumulate radiocesium in environment, even though many minerals are involved in soil. These facts suggest that fungus affect the migration behavior of radiocesium in the environment. However, accumulation mechanism of radiocesium by fungus is not understood. In the present study, accumulation and chemical states change of Cs by unicellular fungus of Saccharomyces cerevisiae have been studied to elucidate the role of microorganisms in the migration of radiocesium in the environment. Two different experimental conditions were employed; one is the accumulation experiments of radiocesium by S. cerevisiae from the agar medium containing 137Cs and a mineral of zeolite, vermiculite, smectite, mica, or illite. The other is the experiments using stable cesium to examine the chemical states change of Cs. In the former experiment, the cells were grown on membrane filter of 0.45 μm installed on the agar medium. After the grown cells were weighed, radioactivity in the cells was measured by an autoradiography technique. The mineral weight contents were changed from 0.1% to 1% of the medium. In the latter experiment, the cells were grown in the medium containing stable Cs between 1 mM and 10mM. The Cs accumulated cells were analyzed by SEM-EDS and EXAFS. The adsorption experiments of cesium by the cells under resting condition were also conducted to test the effect of cells metabolic activity. Without mineral in the medium, cells of S. cerevisiae accumulated 1.5x103 Bq/g from the medium containing 137Cs of 2.6x102 Bq/g. When mineral was added in the medium, concentration of 137Cs in the cells decreased. The concentration of 137Cs in the cells from the medium containing different minerals were in the following order; smectite, illite, mica > vermiculite > zeolite. This order was nearly the same as the inverse of distribution coefficient of

  15. Utilization of inoculum produced on-farm for production of AM fungus colonized pepper and tomato seedlings under conventional management

    Science.gov (United States)

    Arbuscular mycorrhizal [AM] fungus inoculum may be used to produce colonized vegetable seedlings for outplanting. Success depends, in part, upon a nutrient regime in the greenhouse that is conducive to AM fungus hyphal growth and signaling/recognition events between host and fungus. Experiments we...

  16. Protein profiling of the dimorphic, pathogenic fungus, Penicillium marneffei

    Directory of Open Access Journals (Sweden)

    Rundle William T

    2008-06-01

    Full Text Available Abstract Background Penicillium marneffei is a pathogenic fungus that afflicts immunocompromised individuals having lived or traveled in Southeast Asia. This species is unique in that it is the only dimorphic member of the genus. Dimorphism results from a process, termed phase transition, which is regulated by temperature of incubation. At room temperature, the fungus grows filamentously (mould phase, but at body temperature (37°C, a uninucleate yeast form develops that reproduces by fission. Formation of the yeast phase appears to be a requisite for pathogenicity. To date, no genes have been identified in P. marneffei that strictly induce mould-to-yeast phase conversion. In an effort to help identify potential gene products associated with morphogenesis, protein profiles were generated from the yeast and mould phases of P. marneffei. Results Whole cell proteins from the early stages of mould and yeast development in P. marneffei were resolved by two-dimensional gel electrophoresis. Selected proteins were recovered and sequenced by capillary-liquid chromatography-nanospray tandem mass spectrometry. Putative identifications were derived by searching available databases for homologous fungal sequences. Proteins found common to both mould and yeast phases included the signal transduction proteins cyclophilin and a RACK1-like ortholog, as well as those related to general metabolism, energy production, and protection from oxygen radicals. Many of the mould-specific proteins identified possessed similar functions. By comparison, proteins exhibiting increased expression during development of the parasitic yeast phase comprised those involved in heat-shock responses, general metabolism, and cell-wall biosynthesis, as well as a small GTPase that regulates nuclear membrane transport and mitotic processes in fungi. The cognate gene encoding the latter protein, designated RanA, was subsequently cloned and characterized. The P. marneffei RanA protein

  17. Directed evolution of a filamentous fungus for thermotolerance

    Directory of Open Access Journals (Sweden)

    Lyons Thomas J

    2009-08-01

    Full Text Available Abstract Background Filamentous fungi are the most widely used eukaryotic biocatalysts in industrial and chemical applications. Consequently, there is tremendous interest in methodology that can use the power of genetics to develop strains with improved performance. For example, Metarhizium anisopliae is a broad host range entomopathogenic fungus currently under intensive investigation as a biologically based alternative to chemical pesticides. However, it use is limited by the relatively low tolerance of this species to abiotic stresses such as heat, with most strains displaying little to no growth between 35–37°C. In this study, we used a newly developed automated continuous culture method called the Evolugator™, which takes advantage of a natural selection-adaptation strategy, to select for thermotolerant variants of M. anisopliae strain 2575 displaying robust growth at 37°C. Results Over a 4 month time course, 22 cycles of growth and dilution were used to select 2 thermotolerant variants of M. anisopliae. Both variants displayed robust growth at 36.5°C, whereas only one was able to grow at 37°C. Insect bioassays using Melanoplus sanguinipes (grasshoppers were also performed to determine if thermotolerant variants of M. anisopliae retained entomopathogenicity. Assays confirmed that thermotolerant variants were, indeed, entomopathogenic, albeit with complex alterations in virulence parameters such as lethal dose responses (LD50 and median survival times (ST50. Conclusion We report the experimental evolution of a filamentous fungus via the novel application of a powerful new continuous culture device. This is the first example of using continuous culture to select for complex phenotypes such as thermotolerance. Temperature adapted variants of the insect-pathogenic, filamentous fungus M. anisopliae were isolated and demonstrated to show vigorous growth at a temperature that is inhibitory for the parent strain. Insect virulence assays

  18. Cytotoxic sesquiterpenes from the endophytic fungus Pseudolagarobasidium acaciicola.

    Science.gov (United States)

    Wibowo, Mario; Prachyawarakorn, Vilailak; Aree, Thammarat; Mahidol, Chulabhorn; Ruchirawat, Somsak; Kittakoop, Prasat

    2016-02-01

    Twenty previously unknown compounds and two known metabolites, merulin A and merulin D, were isolated from the endophytic fungus Pseudolagarobasidium acaciicola, which was isolated from a mangrove tree, Bruguiera gymnorrhiza. Structures of the 20 compounds were elucidated by analysis of spectroscopic data. The absolute configuration of seven of these compounds was addressed by a single crystal X-ray analysis using CuKα radiation and an estimate of the Flack parameter. Three compounds also possessed a tricyclic ring system. Terpene endoperoxides isolated exhibited cytotoxic activity, while those without an endoperoxide moiety did not show activity. The endoperoxide moiety of sesquiterpenes has significant impact on cytotoxic activity, and thus is an important functionality for cytotoxicity. One terpene endoperoxide displayed potent cytotoxic activity (IC50 0.28μM), and selectively exhibited activity against the HL-60 cell line. PMID:26701647

  19. Biosorption of cadmium using the fungus Aspergillus niger

    Directory of Open Access Journals (Sweden)

    L.M. Barros Júnior

    2003-09-01

    Full Text Available Sorption experiments using the Aspergillus niger fungus for cadmium removal were carried out to study the factors influencing and optimizing the biosorption of this metal. The effects of pH, time, biomass concentration, and initial concentration of the heavy metal on the rate of metallic biosorption were examined. An experimental design was also used to determine the values of the under study variables that provided the greatest biosorption efficiency. A technique for biomass recovery was also developed with the objective of determining the capacity of the regenerated biomass to biosorb the metals in solution. This research proved that with a pH of 4.75, a biomass concentration of 0.7 g/L, and a heavy metal concentration varying between 5 and 10 mg/L a biosorption process of biosorption with Aspergillus niger could be successfully used for heavy metal removal from oil field water in the oil industry.

  20. Garden sharing and garden stealing in fungus-growing ants

    Science.gov (United States)

    Adams, Rachelle M. M.; Mueller, U. G.; Holloway, Alisha K.; Green, Abigail M.; Narozniak, Joanie

    Fungi cultivated by fungus-growing ants (Attini: Formicidae) are passed on between generations by transfer from maternal to offspring nest (vertical transmission within ant species). However, recent phylogenetic analyses revealed that cultivars are occasionally also transferred between attine species. The reasons for such lateral cultivar transfers are unknown. To investigate whether garden loss may induce ants to obtain a replacement cultivar from a neighboring colony (lateral cultivar transfer), pairs of queenright colonies of two Cyphomyrmex species were set up in two conjoined chambers; the garden of one colony was then removed to simulate the total crop loss that occurs naturally when pathogens devastate gardens. Garden-deprived colonies regained cultivars through one of three mechanisms: joining of a neighboring colony and cooperation in a common garden; stealing of a neighbor's garden; or aggressive usurpation of a neighbor's garden. Because pathogens frequently devastate attine gardens under natural conditions, garden joining, stealing and usurpation emerge as critical behavioral adaptations to survive garden catastrophes.

  1. The complete mitochondrial genome of the nematophagous fungus Acremonium implicatum.

    Science.gov (United States)

    Yao, Yurong; Lin, Runmao; Tian, Xueliang; Shen, Baoming; Mao, Zhenchuan; Xie, Bingyan

    2016-09-01

    The complete mitochondrial genome of the nematophagous fungus Acremonium implicatum is reported for the first time. The genome is concatenated with 22,367 bp in length, encoding 13 protein-coding genes, 2 ribosomal RNA genes and a set of 17 transfer RNA genes. The synteny analysis reveals that 50.35% of A. implicatum mitochondrial sequences matched to 48.21% of Acremonium chrysogenum mitochondrial sequences with 85.68% identity. Two proteins of cox3 and nad6, as well as seven tRNAs are lost in A. implicatum mitogenome compared to A. chrysogenum mitogenome. The gene orders in A. implicatum and A. chrysogenum mitogenome is different, which is mainly due to the location of nad4 and cox2. In addition, one transposition event related to tRNAs is identified in these two mitogenomes. This study may provide valuable mitochondrial information for research on A. implicatum and facilitate the study of mitochondrial evolution. PMID:25630733

  2. Identification of Oxaphenalenone Ketals from the Ascomycete Fungus Neonectria sp.

    Science.gov (United States)

    Ren, Jinwei; Niu, Shubing; Li, Li; Geng, Zhufeng; Liu, Xingzhong; Che, Yongsheng

    2015-06-26

    Neonectrolides B-E (4-7), four new oxaphenalenone ketals incorporating the new furo[2,3-b]isochromeno[3,4,5-def]chromen-11(6aH)-one skeleton, were isolated from the fermentation extract of the ascomycete fungus Neonectria sp. in an in-depth investigation guided by HPLC fingerprint and a cytotoxicity assay. The previously identified oxaphenalenone spiroketal neonectrolide A (1) and its putative biosynthetic precursors (2 and 3) were also reisolated in the current work. The structures of 4-7 were primarily elucidated by interpretation of NMR spectroscopic data, and the absolute configurations were deduced by electronic circular dichroism calculations. Compound 6 showed cytotoxic effects against four of the six human tumor cell lines tested. Biosynthetically, compounds 4-7 could be derived via the Diels-Alder reaction cascades starting from derivatives of the co-isolated metabolites 2 and 3. PMID:25978132

  3. Vincamine-producing endophytic fungus isolated from Vinca minor.

    Science.gov (United States)

    Yin, Hong; Sun, Yu-Hong

    2011-06-15

    Vinca minor is a plant containing the alkaloid vincamine, which is used in the pharmaceutical industry as a cerebral stimulant and vasodilator. The objective of this study was to determine whether endophytic fungi isolated from V. minor produce vincamine. Primary screening was carried out using Dragendorff's and Mayer's reactions, and strain re-selection was made by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) to identify the fermentation products of the selected strain. We isolated 10 endophytic fungal strains from V. minor. An extract from one (Vm-J2), showed positive reactions with both Dragendorff's and Mayer's reagents. The strain had a component with the same TLC R(f) value and HPLC retention time as authentic vincamine. Therefore, the fungus appeared to produce the same bioactive ingredient, vincamine, as the host plant. The prospect of using endophytic fungi to produce the phytoactive compound by fungal fermentation is discussed. PMID:21315568

  4. New Bergamotane Sesquiterpenoids from the Plant Endophytic Fungus Paraconiothyrium brasiliense.

    Science.gov (United States)

    Guo, Zhe; Ren, Fengxia; Che, Yongsheng; Liu, Gang; Liu, Ling

    2015-01-01

    Brasilamides K-N (1-4), four new bergamotane sesquiterpenoids; with 4-oxatricyclo (3.3.1.0 (2,7))nonane (1)and 9-oxatricyclo(4.3.0.0 (4,7))nonane (2-4) skeletons; were isolated from the scale-up fermentation cultures of the plant endophytic fungus Paraconiothynium brasiliense Verkley. The previously identified sesquiterpenoids brasilamides A and C (5 and 6) were also reisolated in the current work. The structures of 1-4 were elucidated primarily by interpretation of NMR spectroscopic data. The absolute configurations of 1-3 were deduced by analogy to the co-isolated metabolites 5 and 6; whereas that of C-12 in 4 was assigned using the modified Mosher method. The cytotoxicity of all compounds against a panel of eight human tumor cell lines were assayed. PMID:26274948

  5. Enzymes and bioproducts produced by the ascomycete fungus Paecilomyces variotii.

    Science.gov (United States)

    Herrera Bravo de Laguna, I; Toledo Marante, F J; Mioso, R

    2015-12-01

    Due its innate ability to produce extracellular enzymes which can provide eco-friendly solutions for a variety of biotechnological applications, Paecilomyces variotii is a potential source of industrial bioproducts. In this review, we report biotechnological records on the biochemistry of different enzymes produced by the fermentation of the P. variotii fungus, including tannases, phytases, cellulases, xylanases, chitinases, amylases and pectinases. Additionally, the main physicochemical properties which can affect the enzymatic reactions of the enzymes involved in the conversion of a huge number of substrates to high-value bioproducts are described. Despite all the background information compiled in this review, more research is required to consolidate the catalytic efficiency of P. variotii, which must be optimized so that it is more accurate and reproducible on a large scale. PMID:26274842

  6. Sperm length evolution in the fungus-growing ants

    DEFF Research Database (Denmark)

    Baer, B.; Dijkstra, M. B.; Mueller, U. G.;

    2009-01-01

    -growing ants, representing 9 of the 12 recognized genera, and mapped these onto the ant phylogeny. We show that average sperm length across species is highly variable and decreases with mature colony size in basal genera with singly mated queens, suggesting that sperm production or storage constraints affect...... the evolution of sperm length. Sperm length does not decrease further in multiply mating leaf-cutting ants, despite substantial further increases in colony size. In a combined analysis, sexual dimorphism explained 63.1% of the variance in sperm length between species. As colony size was not a...... significant predictor in this analysis, we conclude that sperm production trade-offs in males have been the major selective force affecting sperm length across the fungus-growing ants, rather than storage constraints in females. The relationship between sperm length and sexual dimorphism remained robust in...

  7. Disposable diapers biodegradation by the fungus Pleurotus ostreatus.

    Science.gov (United States)

    Espinosa-Valdemar, Rosa María; Turpin-Marion, Sylvie; Delfín-Alcalá, Irma; Vázquez-Morillas, Alethia

    2011-08-01

    This research assesses the feasibility of degrading used disposable diapers, an important component (5-15% in weight) of urban solid waste in Mexico, by the activity of the fungus Pleurotus ostreatus, also known as oyster mushroom. Disposable diapers contain polyethylene, polypropylene and a super absorbent polymer. Nevertheless, its main component is cellulose, which degrades slowly. P. ostreatus has been utilized extensively to degrade cellulosic materials of agroindustrial sources, using in situ techniques. The practice has been extended to the commercial farming of the mushroom. This degradation capacity was assayed to reduce mass and volume of used disposable diapers. Pilot laboratory assays were performed to estimate the usefulness of the following variables on conditioning of used diapers before they act as substrate for P. ostreatus: (1) permanence vs removal of plastic cover; (2) shredding vs grinding; (3) addition of grape wastes to improve structure, nitrogen and trace elements content. Wheat straw was used as a positive control. After 68 days, decrease of the mass of diapers and productivity of fungus was measured. Weight and volume of degradable materials was reduced up to 90%. Cellulose content was diminished in 50% and lignine content in 47%. The highest efficiency for degradation of cellulosic materials corresponded to the substrates that showed highest biological efficiency, which varied from 0% to 34%. Harvested mushrooms had good appearance and protein content and were free of human disease pathogens. This research indicates that growing P. ostreatus on disposable diapers could be a good alternative for two current problems: reduction of urban solid waste and availability of high protein food sources. PMID:21474296

  8. Cladosporium sp. , a potential fungus for bioremediation of wood-treating wastes

    Energy Technology Data Exchange (ETDEWEB)

    Borazjani, H.; Ferguson, B.; Hendrix, F.; McFarland, L.; McGinnis, G.; Pope, D.; Strobel, D.; Wagner, J. (Mississippi Forest Products Utilization Lab., Mississippi State (USA))

    1989-01-01

    A fungus, Cladosporium sp., was isolated from a very old wood-treating plant sludge pond in Weed, California. A preliminary study showed no inhibition of mycelial growth at 5,500 {mu}g polycyclic aromatic hydrocarbons (PAH) per ml of potato dextrose agar (PDA). Pentachlorophenol (PCP) inhibited mycelial growth at 10 {mu}g/ml of PDA. Rates of breakdown of both PAHs and PCP in the soil and water system were studied using this fungus. The results of this study and the application of this fungus for cleaning up contaminated sites will be discussed.

  9. Widespread occurrence of bd in French Guiana, South America.

    Directory of Open Access Journals (Sweden)

    Elodie A Courtois

    Full Text Available The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd is a purported agent of decline and extinction of many amphibian populations worldwide. Its occurrence remains poorly documented in many tropical regions, including the Guiana Shield, despite the area's high amphibian diversity. We conducted a comprehensive assessment of Bd in French Guiana in order to (1 determine its geographical distribution, (2 test variation of Bd prevalence among species in French Guiana and compare it to earlier reported values in other South American anuran species (http://www.bd-maps.net; 123 species from 15 genera to define sentinel species for future work, (3 track changes in prevalence through time and (4 determine if Bd presence had a negative effect on one selected species. We tested the presence of Bd in 14 species at 11 sites for a total of 1053 samples (306 in 2009 and 747 in 2012. At least one Bd-positive individual was found at eight out of 11 sites, suggesting a wide distribution of Bd in French Guiana. The pathogen was not uniformly distributed among the studied amphibian hosts, with Dendrobatidae species displaying the highest prevalence (12.4% as compared to Bufonidae (2.6 % and Hylidae (1.5%. In contrast to earlier reported values, we found highest prevalence for three Dendrobatidae species and two of them displayed an increase in Bd prevalence from 2009 to 2012. Those three species might be the sentinel species of choice for French Guiana. For Dendrobates tinctorius, of key conservation value in the Guiana Shield, smaller female individuals were more likely to be infected, suggesting either that frogs can outgrow their chytrid infections or that the disease induces developmental stress limiting growth. Generally, our study supports the idea that Bd is more widespread than previously thought and occurs at remote places in the lowland forest of the Guiana shield.

  10. The dynamics of plant cell-wall polysaccharide decomposition in leaf-cutting ant fungus gardens

    DEFF Research Database (Denmark)

    Moller, Isabel Eva; de Fine Licht, Henrik Hjarvard; Harholt, Jesper;

    2011-01-01

    The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus...... map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste...... material that the ants remove from their fungus garden. These results demonstrate that biomass entering leaf-cutting ant fungus gardens is only partially utilized and explain why disproportionally large amounts of plant material are needed to sustain colony growth. They also explain why substantial...

  11. Biosorption of copper(II and chromium(VI by modified tea fungus

    Directory of Open Access Journals (Sweden)

    Šćiban Marina B.

    2012-01-01

    Full Text Available The tea fungus was found to have good adsorption capacities for heavy metal ions. In this work it was treated with HCl or NaOH at 20°C or 100°C, with the aim to improve its adsorption ability. The sorption of Cu(II and Cr(VI ions from aqueous solutions by raw and treated tea fungus was investigated in the batch mode. The largest quantity of adsorbed Cu(II, of about 55 mg/g, was achieved by tea fungus modified with NaOH at 100°C. For Cr(VI, the largest quantity of adsorbed anions, of about 58 mg/g, was achieved by the adsorbent modified with NaOH at 20°C. It was shown that acid modification of tea fungus biomass was not effective. [Projekat Ministarstva nauke Republike Srbije, br. III 43005 i br. TR 31002

  12. Levels of specificity of Xylaria species associated with fungus-growing termites: a phylogenetic approach

    DEFF Research Database (Denmark)

    Visser, Andre; Ros, V I D; De Beer, Z. W.;

    2009-01-01

    Fungus-growing termites live in obligate mutualistic symbiosis with species of the basidiomycete genus Termitomyces, which are cultivated on a substrate of dead plant material. When the termite colony dies, or when nest material is incubated without termites in the laboratory, fruiting bodies of...... the ascomycete genus Xylaria appear and rapidly cover the fungus garden. This raises the question whether certain Xylaria species are specialised in occupying termite nests or whether they are just occasional visitors. We tested Xylaria specificity at four levels: (1) fungus-growing termites, (2......) termite genera, (3) termite species, and (4) colonies. In South Africa, 108 colonies of eight termite species from three termite genera were sampled for Xylaria. Xylaria was isolated from 69% of the sampled nests and from 57% of the incubated fungus comb samples, confirming high prevalence. Phylogenetic...

  13. Deciphering the molecular mechanisms behind cellulase production in Trichoderma reesei, the hyper-cellulolytic filamentous fungus.

    Science.gov (United States)

    Shida, Yosuke; Furukawa, Takanori; Ogasawara, Wataru

    2016-09-01

    The filamentous fungus Trichoderma reesei is a potent cellulase producer and the best-studied cellulolytic fungus. A lot of investigations not only on glycoside hydrolases produced by T. reesei, but also on the machinery controlling gene expression of these enzyme have made this fungus a model organism for cellulolytic fungi. We have investigated the T. reesei strain including mutants developed in Japan in detail to understand the molecular mechanisms that control the cellulase gene expression, the biochemical and morphological aspects that could favor this phenotype, and have attempted to generate novel strains that may be appropriate for industrial use. Subsequently, we developed recombinant strains by combination of these insights and the heterologous-efficient saccharifing enzymes. Resulting enzyme preparations were highly effective for saccharification of various biomass. In this review, we present some of the salient findings from the recent biochemical, morphological, and molecular analyses of this remarkable cellulase hyper-producing fungus. PMID:27075508

  14. A role for antioxidants in acclimation of marine derived pathogenic fungus (NIOCC 1) to salt stress

    Digital Repository Service at National Institute of Oceanography (India)

    Ravindran, C.; Varatharajan, G.R.; Rajasabapathy, R.; Vijayakanth, S.; HarishKumar, A.; Meena, R.M.

    fungus tackles the oxidative burst i.e. hypersensitivity reaction performed by host to kill the pathogens. 2. Materials and Methods 2.1. Chemicals Sodium bicarbonate, Folins–Ciocalteu reagent, Gallic acid, Sodium nitrite (NaNO 2 ), Aluminium...

  15. Biodegradation of hazardous waste using white rot fungus: Project planning and concept development document

    International Nuclear Information System (INIS)

    The white rot fungus Phanerochaete chrysosporium has been shown to effectively degrade pollutants such as trichlorophenol, polychlorinated biphenyls (PCBs), dioxins and other halogenated aromatic compounds. These refractory organic compounds and many others have been identified in the tank waste, groundwater and soil of various US Department of Energy (DOE) sites. The treatment of these refractory organic compounds has been identified as a high priority for DOE's Research, Development, Demonstration, Testing, and Evaluation (RDDT ampersand E) waste treatment programs. Unlike many bacteria, the white rot fungus P. chrysosporium is capable of degrading these types of refractory organics and may be valuable for the treatment of wastes containing multiple pollutants. The objectives of this project are to identify DOE waste problems amenable to white rot fungus treatment and to develop and demonstrate white rot fungus treatment process for these hazardous organic compounds. 32 refs., 6 figs., 7 tabs

  16. Fungal metabolites: Tetrahydroauroglaucin and isodihydroauroglaucin from the marine fungus,iEurotium sp.

    Digital Repository Service at National Institute of Oceanography (India)

    Gawas, D.; PrabhaDevi; Tilvi, S.; Naik, C.G.; Parameswaran, P.S.

    Two poly substituted aromatic compounds: tetrahydroauroglaucin 1 and isodihydroauroglaucin 2 were identified from a marine fungus, Eurotium sp. isolated from leaves of the mangrove, Porteresia coarctata (Roxb). These compounds were reported earlier...

  17. Investigating the biology of plant infection by the rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Martin-Urdiroz, Magdalena; Oses-Ruiz, Miriam; Ryder, Lauren S; Talbot, Nicholas J

    2016-05-01

    The rice blast fungus, Magnaporthe oryzae, is responsible for the most serious disease of rice and is a continuing threat to ensuring global food security. The fungus has also, however, emerged as a model experimental organism for understanding plant infection processes by pathogenic fungi. This is largely due to its amenability to both classical and molecular genetics, coupled with the efforts of a very large international research community. This review, which is based on a plenary presentation at the 28th Fungal Genetics Conference in Asilomar, California in March 2015, describes recent progress in understanding how M. oryzae uses specialised cell called appressoria to bring about plant infection and the underlying biology of this developmental process. We also review how the fungus is then able to proliferate within rice tissue, deploying effector proteins to facilitate its spread by suppressing plant immunity and promoting growth and development of the fungus. PMID:26703899

  18. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

    NARCIS (Netherlands)

    Bukhari, S.T.; Middelman, A.; Koenraadt, C.J.M.; Takken, W.; Knols, B.G.J.

    2010-01-01

    Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density), fungus (species

  19. Accumulation in Infected Rice Leaves, Antifungal Activity and Detoxification by Fungus

    OpenAIRE

    Morifumi Hasegawa; Ichiro Mitsuhara; Shigemi Seo; Kazunori Okada; Hisakazu Yamane; Takayoshi Iwai; Yuko Ohashi

    2014-01-01

    To understand the role of the rice flavonoid phytoalexin (PA) sakuranetin for blast resistance, the fungus-responsive characteristics were studied. Young rice leaves in a resistant line exhibited hypersensitive reaction (HR) within 3 days post inoculation (dpi) of a spore suspension, and an increase in sakuranetin was detected at 3 dpi, increasing to 4-fold at 4 dpi. In the susceptible line, increased sakuranetin was detected at 4 dpi, but not at 3 dpi, by which a large fungus mass has accum...

  20. Vertical transmission as the key to the colonization of Madagascar by fungus-growing termites?

    OpenAIRE

    Nobre, T.; Eggleton, P.; Aanen, D.K.

    2010-01-01

    The mutualism between fungus-growing termites (Macrotermitinae) and their mutualistic fungi (Termitomyces) began in Africa. The fungus-growing termites have secondarily colonized Madagascar and only a subset of the genera found in Africa is found on this isolated island. Successful long-distance colonization may have been severely constrained by the obligate interaction of the termites with fungal symbionts and the need to acquire these symbionts secondarily from the environment for most spec...

  1. Treatment of a Textile Effluent from Dyeing with Cochineal Extracts Using Trametes versicolor Fungus

    OpenAIRE

    Gabriela Arroyo-Figueroa; Graciela M. L. Ruiz-Aguilar; Leticia López-Martínez; Guillermo González-Sánchez; Germán Cuevas-Rodríguez; Refugio Rodríguez-Vázquez

    2011-01-01

    Trametes versicolor (Tv) fungus can degrade synthetic dyes that contain azo groups, anthraquinone, triphenylmethane polymers, and heterocyclic groups. However, no references have been found related to the degradation of natural dyes, such as the carminic acid that is contained in the cochineal extract. Experiments to determine the decolorization of the effluent used in the cotton dyeing process with cochineal extract by means of Tv fungus were done. Treatments to determine decolorization in t...

  2. Morphological Characteristics of Hyphal Interaction between Grifola umbellata and its Companion Fungus

    OpenAIRE

    Xing, Xiao-Ke; Guo, Shun-xing; Lee, Min-Woong

    2005-01-01

    Morphological characteristics of hyphal interaction between Grifola umbellata (Pers. Ex Fr.) Pilat and its companion fungus which related to sclerotia formation from hyphae were investigated by external observations, light microscopy and transmission electron microscopy (TEM). External observations showed that a dense antagonism line was formed by both G. umbellata and companion fungus after their hyphae contacted each other in dual culture. Many hyphal strands emerged on the colony of G. umb...

  3. Polycyclic aromatic hydrocarbon degradation by the white rot fungus Bjerkandera sp. strain BOS55.

    OpenAIRE

    Kotterman, M.J.J.

    1998-01-01

    Outline of this thesisIn this thesis the conditions for optimal PAH oxidation by the white rot fungus Bjerkandera sp. strain BOS55 were evaluated. In Chapter 2, culture conditions like aeration and cosubstrate concentrations, which influenced the oxidation of the PAH compound anthracene and the ligninolytic indicator dye Poly R-478 by the white rot fungus, were studied. Two parameters were identified as the most important PAH oxidation rate-limiting factors: the hydrogen peroxide production r...

  4. Sex slows down the accumulation of deleterious mutations in the homothallic fungus Aspergillus nidulans.

    OpenAIRE

    Bruggeman, Judith; Debets, Alfons J. M.; Wijngaarden, Pieter J.; deVisser, J Arjan G M; Hoekstra, Rolf F.

    2003-01-01

    Coexistence of sexual and asexual reproduction within the same individual is an intriguing problem, especially when it concerns homothallic haplonts, like the fungus Aspergillus nidulans. In this fungus asexual and sexual offspring have largely identical genotypes. This genetic model organism is an ideal tool to measure possible fitness effects of sex (compared to asex) resulting from causes other than recombination. In this article we show that slightly deleterious mutations accumulate at a ...

  5. The Role of Cross Pathway Control-2 (cpc-2) in Filamentous Fungus Neurospora Crassa

    OpenAIRE

    Garud, Amruta Vikas

    2013-01-01

    In the filamentous fungus Neurospora crassa, heterotrimeric G protein pathways are major signaling cascades through which the fungus senses and adapts to its environment. The characterized Gβ subunit of N. crassa, GNB-1, has seven tryptophan-aspartate (WD) repeats, predicted to result in a β propeller structure. Another related N. crassa protein, called Cross Pathway Control-2 (CPC-2), also has a seven WD repeat structure and possesses 70% positional identity with Receptor for Activ...

  6. Evaluation of the bioremediation ability of the isolated white rot fungus on the textile effluents

    OpenAIRE

    Indira Priyadarsini* R; V Bhuvaneswari; K. Suresh Kumar

    2012-01-01

    Every one contributes to the environmental pollution by theiractivities either directly or indirectly and it is our moral responsibility to uncover a solution in order to come out of it also. Hence an attempt was made to isolate a white rot fungus with better remediation ability. The white rot fungus was isolated from decay wood sample and identified as Trametes hirsuta by molecular identification methods. The assessment of the bioremediation ability of the isolated organism was done with fou...

  7. Antifungal Metabolites Produced by Chaetomium globosum No.04, an Endophytic Fungus Isolated from Ginkgo biloba

    OpenAIRE

    Zhang, Guizhen; Zhang, Yanhua; Qin, Jianchun; Qu, Xiaoyan; Liu, Jinliang; Xiang LI; Pan, Hongyu

    2013-01-01

    The fungal endophyte Chaetomium globosum No.04 was isolated from the medicinal plant Ginkgo biloba. The crude extract of the fungus fermentation were active in the agar-diffusion tests against the phytopathogenic fungi Rhizopus stolonifer and Coniothyrium diplodiella. Further bioassay-guided chemical investigation led to the isolation and purification of six alkaloids and three non-targeted compounds from 50 L fermentation of this endophytic fungus and their structures were elucidated as chae...

  8. Boty, a long-terminal-repeat retroelement in the phytopathogenic fungus Botrytis cinerea.

    OpenAIRE

    Diolez, A; Marches, F; Fortini, D; Brygoo, Y

    1995-01-01

    The phytopathogenic fungus Botrytis cinerea can infect an extremely wide range of host plants (tomato, grapevine, strawberry, and flax) without apparent specialization. While studying genetic diversity in this fungus, we found an element which is present in multiple copies and dispersed throughout the genome of some of its isolates. DNA sequence analysis revealed that the element contained direct, long-terminal repeats (LTRs) of 596 bp whose features were characteristic of retroviral and retr...

  9. Tea fungus fermentation on a substrate with iron(ii)-ions

    OpenAIRE

    Malbaša Radomir V.; Lončar Eva S.; Kolarov Ljiljana A.

    2002-01-01

    Iron is essential element for human metabolism and it is a constituent of both heme- containing and nonheme proteins. Its deficiency can cause serious diseases, i.e. iron-deficiency anemia, with some fatal consequences. Tea fungus beverage has high nutritional value and some pharmaceutical effects. It is widely consumed allover the world and its benefits were proved a number of times. The aim of this paper was to investigate tea fungus fermentation on a substrate containing iron(II)-ions and ...

  10. Ethanol effect on metabolic activity of the ethalogenic fungus Fusarium oxysporum

    OpenAIRE

    Paschos, Thomas; Xiros, Charilaos; Christakopoulos, Paul

    2015-01-01

    Background Fusarium oxysporum is a filamentous fungus which has attracted a lot of scientific interest not only due to its ability to produce a variety of lignocellulolytic enzymes, but also because it is able to ferment both hexoses and pentoses to ethanol. Although this fungus has been studied a lot as a cell factory, regarding applications for the production of bioethanol and other high added value products, no systematic study has been performed concerning its ethanol tolerance levels. Re...

  11. The dynamics of plant cell-wall polysaccharide decomposition in leaf-cutting ant fungus gardens.

    Directory of Open Access Journals (Sweden)

    Isabel E Moller

    Full Text Available The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus degrades cellulose have hampered our understanding of the selection forces that induced large scale herbivory and of the ensuing ecological footprint of these ants. Here we use a recently established technique, based on polysaccharide microarrays probed with antibodies and carbohydrate binding modules, to map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste material that the ants remove from their fungus garden. These results demonstrate that biomass entering leaf-cutting ant fungus gardens is only partially utilized and explain why disproportionally large amounts of plant material are needed to sustain colony growth. They also explain why substantial communities of microbial and invertebrate symbionts have evolved associations with the dump material from leaf-cutting ant nests, to exploit decomposition niches that the ant garden-fungus does not utilize. Our approach thus provides detailed insight into the nutritional benefits and shortcomings associated with fungus-farming in ants.

  12. The fungus gardens of leaf-cutter ants undergo a distinct physiological transition during biomass degradation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Eric L.; Aylward, Frank O.; Kim, Young-Mo; Webb-Robertson, Bobbie-Jo M.; Nicora, Carrie D.; Hu, Zeping; Metz, Thomas O.; Lipton, Mary S.; Smith, Richard D.; Currie, Cameron R.; Burnum-Johnson, Kristin E.

    2014-08-01

    Leaf-cutter ants are dominant herbivores in ecosystems throughout the Neotropics. Rather than directly consuming the fresh foliar biomass they harvest, these ants use it to cultivate specialized fungus gardens. Although recent investigations have shed light on how plant biomass is degraded in fungus gardens, the cycling of nutrients that takes place in these specialized microbial ecosystems is still not well understood. Here, using metametabolomics and metaproteomics techniques, we examine the dynamics of nutrient turnover and biosynthesis in these gardens. Our results reveal that numerous free amino acids and sugars are depleted throughout the process of biomass degradation, indicating that easily accessible nutrients from plant material are readily consumed by microbes in these ecosystems. Accumulation of cellobiose and lignin derivatives near the end of the degradation process is consistent with previous findings of cellulases and laccases produced by Leucoagaricus gongylophorus, the fungus cultivated by leaf-cutter ants. Our results also suggest that ureides may be an important source of nitrogen in fungus gardens, especially during nitrogen-limiting conditions. No free arginine was detected in our metametabolomics experiments despite evidence that the host ants cannot produce this amino acid, suggesting that biosynthesis of this metabolite may be tightly regulated in the fungus garden. These results provide new insights into the dynamics of nutrient cycling that underlie this important ant-fungus symbiosis.

  13. Fungal garden making inside bamboos by a non-social fungus-growing beetle.

    Directory of Open Access Journals (Sweden)

    Wataru Toki

    Full Text Available In fungus-growing mutualism, it is indispensable for host animals to establish gardens of the symbiotic fungus as rapidly as possible. How to establish fungal gardens has been well-documented in social fungus-farming insects, whereas poorly documented in non-social fungus-farming insects. Here we report that the non-social, fungus-growing lizard beetle Doubledaya bucculenta (Coleoptera: Erotylidae: Languriinae transmits the symbiotic yeast Wickerhamomyces anomalus from the ovipositor-associated mycangium into bamboo internode cavities and disperses the yeast in the cavities to make gardens. Microbial isolation and cryo-scanning electron microscopy observation revealed that W. anomalus was constantly located on the posterior ends of eggs, where larvae came out, and on the inner openings of oviposition holes. Direct observation of oviposition behavior inside internodes revealed that the distal parts of ovipositors showed a peristaltic movement when they were in contact with the posterior ends of eggs. Rearing experiments showed that W. anomalus was spread much more rapidly and widely on culture media and internodes in the presence of the larvae than in the absence. These results suggest that the ovipositors play a critical role in vertical transmission of W. anomalus and that the larvae contribute actively to the garden establishment, providing a novel case of fungal garden founding in non-social insect-fungus mutualism.

  14. Optimization of exopectinase activity of the fungus Monilia isolated from tangerine in submerged fermentation

    Directory of Open Access Journals (Sweden)

    Nafiseh Sadat Naghavi

    2012-01-01

    Full Text Available Introduction: Diverse groups of microscopic fungi are able to degrade polymeric plant tissues such as pectin. Biodegradation of these materials are mostly applicable in food industries.Materials and Methods: In the present study, the exopectinase producing fungus was isolated from decaying tangerine and its exopectinase activity was studied in submerged fermenting condition. Also, the enzyme production of the isolated fungus was compared to the industrial fungus, Aspergillus niger PTCC 5013. The exopectinase production and activity of the extracted enzyme solution with respect to pH, temperature, activity timing and substrate concentration were scrutinized.Results: According to the morphological macroscopic and microscopic features, the isolated fungus was identified as the genus Monilia in the Moniliaceae family. The best exopectinase production was in pH 7 and the best enzyme activity achieved at 50°C, in 30 to 40 minute, 1.5% substrate and the 1:1 of the enzyme solution to the substrate solution ratio. The isolated fungus, Monilia, was fast growing and produced highly active exopectinase enzyme. In optimum condition, its exopectinase activity was 20 units higher than the fungus Aspergillus niger PTCC 5013. Discussion and Conclusion: The exopectinase enzyme was active in a wide ranges of pH and temperatures. As Monilia does not produce toxic compounds, it is proposed for pectinase production, especially in the food industries.

  15. Fungal garden making inside bamboos by a non-social fungus-growing beetle.

    Science.gov (United States)

    Toki, Wataru; Takahashi, Yukiko; Togashi, Katsumi

    2013-01-01

    In fungus-growing mutualism, it is indispensable for host animals to establish gardens of the symbiotic fungus as rapidly as possible. How to establish fungal gardens has been well-documented in social fungus-farming insects, whereas poorly documented in non-social fungus-farming insects. Here we report that the non-social, fungus-growing lizard beetle Doubledaya bucculenta (Coleoptera: Erotylidae: Languriinae) transmits the symbiotic yeast Wickerhamomyces anomalus from the ovipositor-associated mycangium into bamboo internode cavities and disperses the yeast in the cavities to make gardens. Microbial isolation and cryo-scanning electron microscopy observation revealed that W. anomalus was constantly located on the posterior ends of eggs, where larvae came out, and on the inner openings of oviposition holes. Direct observation of oviposition behavior inside internodes revealed that the distal parts of ovipositors showed a peristaltic movement when they were in contact with the posterior ends of eggs. Rearing experiments showed that W. anomalus was spread much more rapidly and widely on culture media and internodes in the presence of the larvae than in the absence. These results suggest that the ovipositors play a critical role in vertical transmission of W. anomalus and that the larvae contribute actively to the garden establishment, providing a novel case of fungal garden founding in non-social insect-fungus mutualism. PMID:24223958

  16. Deciphering the salinity adaptation mechanism in Penicilliopsis clavariiformis AP, a rare salt tolerant fungus from mangrove.

    Science.gov (United States)

    Kashyap, Prem Lal; Rai, Anuradha; Singh, Ruchi; Chakdar, Hillol; Kumar, Sudheer; Srivastava, Alok Kumar

    2016-07-01

    Penicilliopsis clavariiformis AP, a rare salt tolerant fungus reported for the first time from India was identified through polyphasic taxonomy. Scanning electron microscopy showed that the fungus has unique features such as biverticillate penicilli bearing masses of oval to ellipsoidal conidia. The fungus has been characterized for salt tolerance and to understand the relevance of central carbon metabolism in salt stress adaptation. It showed optimal growth at 24 °C and able to tolerate up to 10% (w/v) NaCl. To understand the mechanism of adaptation to high salinity, activities of the key enzymes regulating glycolysis, pentose phosphate pathway, and tricarboxylic acid cycle were investigated under normal (0% NaCl) and saline stress environment (10% NaCl). The results revealed a re-routing of carbon metabolism away from glycolysis to the pentose phosphate pathway (PPP), served as a cellular stress-resistance mechanism in fungi under saline environment. The detection and significant expression of fungus genes (Hsp98, Hsp60, HTB, and RHO) under saline stress suggest that these halotolerance conferring genes from the fungus could have a role in fungus protection and adaptation under saline environment. Overall, the present findings indicate that the rearrangement of the metabolic fluxes distribution and stress related genes play an important role in cell survival and adaptation under saline environment. PMID:26663001

  17. Studies on biosorption of nickel using immobilized fungus, Rhizomucor tauricus

    Directory of Open Access Journals (Sweden)

    K. Kishore Kumar

    2012-11-01

    Full Text Available Rhizomucor tauricus, an industrial fungus, was immobilized in sodium alginate and used as adsorbent for the removal of nickel from aqueous solutions. The biosorption capacity of Ni(II was found to be 394 mg/g of immobilized biomass. It was observed that an increase in pH from 3 to 6 increased the percent adsorption, and an increase in liquid-to-solid ratio from 2 to 10 increased the metal uptake. The percent adsorption was increased when increasing the initial metal concentration from 25 to 100 mg/L. The equilibrium biosorption data was evaluated by Langmuir, Freundlich, and Langmuir-Freundlich (L-R isotherm models, and was best described by the Langmuir and Freundlich isotherms. FTIR analysis revealed that –NH (bending, C–H (stretching, C=O (stretching, and –OH functional groups were mainly responsible for Ni(II biosorption. Thus, this study demonstrated that the immobilized Rhizomucor tauricus biomass could be used as an adsorbent for the treatment of Ni(II from aqueous solution.

  18. Eosinophils in fungus-associated allergic pulmonary disease

    Directory of Open Access Journals (Sweden)

    Sumit eGhosh

    2013-02-01

    Full Text Available Asthma is frequently caused and/or exacerbated by sensitization to fungal allergens, which are ubiquitous in many indoor and outdoor environments. Severe asthma with fungal sensitization is characterized by airway hyperresponsiveness and bronchial constriction in response to an inhaled allergen that is worsened by environmental exposure to airborne fungi and which leads to a disease course that is often very difficult to treat with standard asthma therapies. As a result of complex interactions among inflammatory cells, structural cells, and the intercellular matrix of the allergic lung, patients with sensitization to fungal allergens may experience a greater degree of airway wall remodeling and progressive, accumulated pulmonary dysfunction as part of the disease sequela. From their development in the bone marrow to their recruitment to the lung via chemokine and cytokine networks, eosinophils form an important component of the inflammatory milieu that is associated with this syndrome. Eosinophils are recognized as complex multi-factorial leukocytes with diverse functions in the context of allergic fungal asthma. In this review, we will consider recent advances in our understanding of the molecular mechanisms that are associated with eosinophil development and migration to the allergic lung in response to fungal inhalation, along with the eosinophil’s function in the immune response to and the immunopathology attributed to fungus-associated allergic pulmonary disease.

  19. Devonian landscape heterogeneity recorded by a giant fungus

    Science.gov (United States)

    Boyce, C. Kevin; Hotton, Carol L.; Fogel, Marilyn L.; Cody, George D.; Hazen, Robert M.; Knoll, Andrew H.; Hueber, Francis M.

    2007-05-01

    The enigmatic Paleozoic fossil Prototaxites Dawson 1859 consists of tree-like trunks as long as 8 m constructed of interwoven tubes specimens from five localities differ from contemporaneous vascular plants by exhibiting a carbon isotopic range, within and between localities, of as much as 13‰ δ13C. Pyrolysis gas chromatography mass spectrometry highlights compositional differences between Prototaxites and co-occurring plant fossils and supports interpretation of isotopic distinctions as biological rather than diagenetic in origin. Such a large isotopic range is difficult to reconcile with an autotrophic metabolism, suggesting instead that, consistent with anatomy-based interpretation as a fungus, Prototaxites was a heterotroph that lived on isotopically heterogeneous substrates. Light isotopic values of Prototaxites approximate those of vascular plants from the same localities; in contrast, heavy extremes seen in the Lower Devonian appear to reflect consumption of primary producers with carbon-concentrating mechanisms, such as cryptobiotic soil crusts, or possibly bryophytes. Prototaxites biogeochemistry thus suggests that a biologically heterogeneous mosaic of primary producers characterized land surfaces well into the vascular plant era.

  20. Bioturbation by the Fungus-Gardening Ant, Trachymyrmex septentrionalis.

    Science.gov (United States)

    Tschinkel, Walter R; Seal, Jon N

    2016-01-01

    Soil invertebrates such as ants are thought to be important manipulators of soils in temperate and tropical ecosystems. The fungus gardening ant, Trachymyrmex septentrionalis, is an important agent of biomantling, that is, of depositing soil excavated from below onto the surface, and has been suggested as an agent of bioturbation (moving soil below ground) as well. The amount of bioturbation by this ant was quantified by planting queenright colonies in sand columns consisting of 5 layers of different colored sand. The amount of each color of sand deposited on the surface was determined from April to November 2015. In November, colonies were excavated and the color and amount of sand deposited below ground (mostly as backfill in chambers) was determined. Extrapolated to one ha, T. septentrionalis deposited 800 kg of sand per annum on the surface, and an additional 200 kg (17% of the total excavated) below ground. On average, this mixes 1.3% of the sand from other layers within the top meter of soil per millennium, but this mixing is unlikely to be homogeneous, and probably occurs as "hotspots" in both horizontal and vertical space. Such mixing is discussed as a challenge to sediment dating by optically stimulated luminescence (OSL). PMID:27391485

  1. Fitness-associated sexual reproduction in a filamentous fungus.

    Science.gov (United States)

    Schoustra, Sijmen; Rundle, Howard D; Dali, Rola; Kassen, Rees

    2010-08-10

    Sex is a long-standing evolutionary enigma. Although the majority of eukaryotes reproduce sexually at least sometimes [1-3], the evolution of sex from an asexual ancestor has been difficult to explain because it requires sexually reproducing lineages to overcome the manifold costs of sex, including the destruction of favorable gene combinations created by selection [4, 5]. Conditions for the evolution of sex are much broader if individuals can reproduce either sexually or asexually (i.e., facultative sex) and allocate disproportionately more resources to sex when their fitness is low (fitness-associated-sex or FAS [6-10]). Although facultatively sexual organisms have been shown to engage in more sex when stressed [11], direct evidence for FAS is lacking. We provide evidence using 53 genotypes of the filamentous fungus Aspergillus nidulans in a reciprocal transplant experiment across three environments. Different genotypes achieved highest fitness in different environments and genotypes invested relatively more in sex in environments in which their fitness was lower, showing that allocation to sexual reproduction is a function of how well-adapted a genotype is to its environment. FAS in A. nidulans is unlikely to have evolved as a strategy to resist or avoid stress because asexual spores are more dispersive and equally resistant [12, 13]. PMID:20598542

  2. Biosynthesis of vanillin by the fungus Pycnoporus sanguineus MIP 95001

    Directory of Open Access Journals (Sweden)

    Sabrina Moro Villela Pacheco

    2013-09-01

    Full Text Available Vanillin (a substance popularly known as vanilla flavor is one of the most widely used compounds, mainly by food and pharmaceutical industries. This substance can be obtained from the orchid Vanilla planifolia, but this is costly and time consuming. Thus, other methods for obtaining vanillin have been studied. Within this context, the aim of this work was to study the biosynthesis of vanillin by three strains of Pycnoporus sanguineus through the use of vanillic acid as a precursor. The strains were cultured in Petri dishes with a potato dextrose agar medium. Fragments of the media with the fungus were then inoculated in Erlenmeyer flasks with a liquid medium of potato broth and 0.3 g.L-1 of vanillic acid. The flasks remained in a shaker for eight days at 28°C and 120 rpm. Samples were withdrawn once a day (0.8 mL.day-1 for analysis of vanillin, glucose, total phenols, total proteins, and laccase. The results showed that only the MIP 95001 strain promoted the biosynthesis of vanillin. The highest concentration of vanillin was detected on the fourth day of cultivation (8.75 mg.dL-1. The results illustrate the ability to biosynthesize vanillin using Pycnoporus sanguineus (MIP 95001, which suggests a possible route for the biotechnological production of this flavor.

  3. Cytotoxic effects of Oosporein isolated from endophytic fungus Cochliobolus kusanoi

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    Rmaesha eA

    2015-09-01

    Full Text Available In the present study, oosporein, a fungal toxic secondary metabolite known to be a toxic agent causing chronic disorders in animals, was isolated from fungus Cochliobolus kusanoi of Nerium oleander L. Toxic effects of oosporein and the possible mechanisms of cytotoxicity as well as the role of oxidative stress in cytotoxicity to MDCK kidney cells and RAW 264.7 splene cells were evaluated in-vitro. Also to know the possible in-vivo toxic effects of oosporein on kidney and spleen, Balb/C mouse were treated with different concentrations of oosporein ranging from 20 uM to 200 µM. After 24 hrs of post exposure histopathological observations were made to know the effects of oosporein on target organs. Oosporein induced elevated levels of ROS generation and high levels of MDA, loss of mitochondrial membrane potential (MMP, induced glutathione hydroxylase production was observed in a dose depended manner. Effects oosporein on chromosomal DNA damage was assessed by Comet assay, and increase in DNA damage were observed in both the studied cell lines by increasing the oosprin concentration. Further, oosporein treatment to studied cell lines indicated significant suppression of oxidative stress related gene (SOD1 and CAT expression, and increased levels of mRNA expression in apoptosis or oxidative stress

  4. Bioturbation by the Fungus-Gardening Ant, Trachymyrmex septentrionalis

    Science.gov (United States)

    Tschinkel, Walter R.; Seal, Jon N.

    2016-01-01

    Soil invertebrates such as ants are thought to be important manipulators of soils in temperate and tropical ecosystems. The fungus gardening ant, Trachymyrmex septentrionalis, is an important agent of biomantling, that is, of depositing soil excavated from below onto the surface, and has been suggested as an agent of bioturbation (moving soil below ground) as well. The amount of bioturbation by this ant was quantified by planting queenright colonies in sand columns consisting of 5 layers of different colored sand. The amount of each color of sand deposited on the surface was determined from April to November 2015. In November, colonies were excavated and the color and amount of sand deposited below ground (mostly as backfill in chambers) was determined. Extrapolated to one ha, T. septentrionalis deposited 800 kg of sand per annum on the surface, and an additional 200 kg (17% of the total excavated) below ground. On average, this mixes 1.3% of the sand from other layers within the top meter of soil per millennium, but this mixing is unlikely to be homogeneous, and probably occurs as "hotspots" in both horizontal and vertical space. Such mixing is discussed as a challenge to sediment dating by optically stimulated luminescence (OSL). PMID:27391485

  5. Clinical Evaluation and Management of Patients with Suspected Fungus Sensitivity.

    Science.gov (United States)

    Larenas-Linnemann, Desiree; Baxi, Sachin; Phipatanakul, Wanda; Portnoy, Jay M

    2016-01-01

    Fungus-sensitized patients usually present with symptoms that are similar to symptoms presented by those who are sensitized to other aeroallergens. Therefore, diagnosis and management should follow the same pathways used for patients with allergic conditions in general. The physician should consider that a relationship between fungal exposure and symptoms is not necessarily caused by an IgE-mediated mechanism, even when specific fungal IgE is detected. Until recently, IgE-mediated allergy has been documented only for a limited number of fungi. We propose a series of questions to be used to identify symptoms that occur in situations with high fungal exposure and a limited skin-prick-test panel (Alternaria, Cladosporium, Penicillium, Aspergillus, Candida) that can be amplified only in cases of high suspicion of other fungal exposure (eg, postfloods). We also review in vitro testing for fungi-specific IgE. Treatment includes environmental control, medical management, and, when appropriate, specific immunotherapy. Low-quality evidence exists supporting the use of subcutaneous immunotherapy for Alternaria to treat allergic rhinitis and asthma, and very low quality evidence supports the use of subcutaneous immunotherapy for Cladosporium and sublingual immunotherapy for Alternaria. As is the case for many allergens, evidence for immunotherapy with other fungal extracts is lacking. The so-called toxic mold syndrome is also briefly discussed. PMID:26755100

  6. Swabbing often fails to detect amphibian Chytridiomycosis under conditions of low infection load.

    Science.gov (United States)

    Shin, Jaehyub; Bataille, Arnaud; Kosch, Tiffany A; Waldman, Bruce

    2014-01-01

    The pathogenic chytrid fungus, Batrachochytrium dendrobatidis (denoted Bd), causes large-scale epizootics in naïve amphibian populations. Intervention strategies to rapidly respond to Bd incursions require sensitive and accurate diagnostic methods. Chytridiomycosis usually is assessed by quantitative polymerase chain reaction (qPCR) amplification of amphibian skin swabs. Results based on this method, however, sometimes yield inconsistent results on infection status and inaccurate scores of infection intensity. In Asia and other regions where amphibians typically bear low Bd loads, swab results are least reliable. We developed a Bd-sampling method that collects zoospores released by infected subjects into an aquatic medium. Bd DNA is extracted by filters and amplified by nested PCR. Using laboratory colonies and field populations of Bombina orientalis, we compare results with those obtained on the same subjects by qPCR of DNA extracted from swabs. Many subjects, despite being diagnosed as Bd-negative by conventional methods, released Bd zoospores into collection containers and thus must be considered infected. Infection loads determined from filtered water were at least 1000 times higher than those estimated from swabs. Subjects significantly varied in infection load, as they intermittently released zoospores, over a 5-day period. Thus, the method might be used to compare the infectivity of individuals and study the periodicity of zoospore release. Sampling methods based on water filtration can dramatically increase the capacity to accurately diagnose chytridiomycosis and contribute to a better understanding of the interactions between Bd and its hosts. PMID:25333363

  7. Microscopic aquatic predators strongly affect infection dynamics of a globally emerged pathogen.

    Science.gov (United States)

    Schmeller, Dirk S; Blooi, Mark; Martel, An; Garner, Trenton W J; Fisher, Matthew C; Azemar, Frédéric; Clare, Frances C; Leclerc, Camille; Jäger, Lea; Guevara-Nieto, Michelle; Loyau, Adeline; Pasmans, Frank

    2014-01-20

    Research on emerging infectious wildlife diseases has placed particular emphasis on host-derived barriers to infection and disease. This focus neglects important extrinsic determinants of the host/pathogen dynamic, where all barriers to infection should be considered when ascertaining the determinants of infectivity and pathogenicity of wildlife pathogens. Those pathogens with free-living stages, such as fungi causing catastrophic wildlife declines on a global scale, must confront lengthy exposure to environmental barriers before contact with an uninfected host. Hostile environmental conditions therefore have the ability to decrease the density of infectious particles, reducing the force of infection and ameliorating the impact as well as the probability of establishing an infection. Here we show that, in nature, the risk of infection and infectious burden of amphibians infected by the chytrid fungus Batrachochytrium dendrobatidis (Bd) have a significant, site-specific component, and that these correlate with the microfauna present at a site. Experimental infections show that aquatic microfauna can rapidly lower the abundance and density of infectious stages by consuming Bd zoospores, resulting in a significantly reduced probability of infection in anuran tadpoles. Our findings offer new perspectives for explaining the divergent impacts of Bd infection in amphibian assemblages and contribute to our understanding of ecosystem resilience to colonization by novel pathogens. PMID:24374305

  8. Current extinction rates of reptiles and amphibians.

    Science.gov (United States)

    Alroy, John

    2015-10-20

    There is broad concern that a mass extinction of amphibians and reptiles is now underway. Here I apply an extremely conservative Bayesian method to estimate the number of recent amphibian and squamate extinctions in nine important tropical and subtropical regions. The data stem from a combination of museum collection databases and published site surveys. The method computes an extinction probability for each species by considering its sighting frequency and last sighting date. It infers hardly any extinction when collection dates are randomized and it provides underestimates when artificial extinction events are imposed. The method also appears to be insensitive to trends in sampling; therefore, the counts it provides are absolute minimums. Extinctions or severe population crashes have accumulated steadily since the 1970s and 1980s, and at least 3.1% of frog species have already disappeared. Based on these data and this conservative method, the best estimate of the global grand total is roughly 200 extinctions. Consistent with previous results, frog losses are heavy in Latin America, which has been greatly affected by the pathogenic chytrid fungus Batrachochytrium dendrobatidis. Extinction rates are now four orders-of-magnitude higher than background, and at least another 6.9% of all frog species may be lost within the next century, even if there is no acceleration in the growth of environmental threats. PMID:26438855

  9. Susceptibility of amphibians to chytridiomycosis is associated with MHC class II conformation.

    Science.gov (United States)

    Bataille, Arnaud; Cashins, Scott D; Grogan, Laura; Skerratt, Lee F; Hunter, David; McFadden, Michael; Scheele, Benjamin; Brannelly, Laura A; Macris, Amy; Harlow, Peter S; Bell, Sara; Berger, Lee; Waldman, Bruce

    2015-04-22

    The pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd) can cause precipitous population declines in its amphibian hosts. Responses of individuals to infection vary greatly with the capacity of their immune system to respond to the pathogen. We used a combination of comparative and experimental approaches to identify major histocompatibility complex class II (MHC-II) alleles encoding molecules that foster the survival of Bd-infected amphibians. We found that Bd-resistant amphibians across four continents share common amino acids in three binding pockets of the MHC-II antigen-binding groove. Moreover, strong signals of selection acting on these specific sites were evident among all species co-existing with the pathogen. In the laboratory, we experimentally inoculated Australian tree frogs with Bd to test how each binding pocket conformation influences disease resistance. Only the conformation of MHC-II pocket 9 of surviving subjects matched those of Bd-resistant species. This MHC-II conformation thus may determine amphibian resistance to Bd, although other MHC-II binding pockets also may contribute to resistance. Rescuing amphibian biodiversity will depend on our understanding of amphibian immune defence mechanisms against Bd. The identification of adaptive genetic markers for Bd resistance represents an important step forward towards that goal. PMID:25808889

  10. RANAVIRUS CAUSES MASS DIE-OFFS OF ALPINE AMPHIBIANS IN THE SOUTHWESTERN ALPS, FRANCE.

    Science.gov (United States)

    Miaud, Claude; Pozet, Françoise; Gaudin, Nadine Curt Grand; Martel, An; Pasmans, Frank; Labrut, Sophie

    2016-04-28

    Pathogenic fungi and viruses cause mortality outbreaks in wild amphibians worldwide. In the summer of 2012, dead tadpoles and adults of the European common frog Rana temporaria were reported in alpine lakes in the southwestern Alps (Mercantour National Park, France). A preliminary investigation using molecular diagnostic techniques identified a Ranavirus as the potential pathogenic agent. Three mortality events were recorded in the park, and samples were collected. The amphibian chytrid fungus Batrachochytrium dendrobatidis was not detected in any of the dead adult and juvenile frogs sampled (n=16) whereas all specimens were positive for a Ranavirus. The genome sequence of this Ranavirus was identical to previously published sequences of the common midwife toad virus (CMTV), a Ranavirus that has been associated with amphibian mortalities throughout Europe. We cultured virus from the organs of the dead common frogs and infecting adult male common frogs collected in another alpine region where no frog mortality had been observed. The experimentally infected frogs suffered 100% mortality (n=10). The alpine die-off is the first CMTV outbreak associated with mass mortality in wild amphibians in France. We describe the lesions observed and summarize amphibian populations affected by Ranaviruses in Europe. In addition, we discuss the ecologic specificities of mountain amphibians that may contribute to increasing their risk of exposure to and transmission of Ranaviruses. PMID:26967128

  11. Swabbing often fails to detect amphibian Chytridiomycosis under conditions of low infection load.

    Directory of Open Access Journals (Sweden)

    Jaehyub Shin

    Full Text Available The pathogenic chytrid fungus, Batrachochytrium dendrobatidis (denoted Bd, causes large-scale epizootics in naïve amphibian populations. Intervention strategies to rapidly respond to Bd incursions require sensitive and accurate diagnostic methods. Chytridiomycosis usually is assessed by quantitative polymerase chain reaction (qPCR amplification of amphibian skin swabs. Results based on this method, however, sometimes yield inconsistent results on infection status and inaccurate scores of infection intensity. In Asia and other regions where amphibians typically bear low Bd loads, swab results are least reliable. We developed a Bd-sampling method that collects zoospores released by infected subjects into an aquatic medium. Bd DNA is extracted by filters and amplified by nested PCR. Using laboratory colonies and field populations of Bombina orientalis, we compare results with those obtained on the same subjects by qPCR of DNA extracted from swabs. Many subjects, despite being diagnosed as Bd-negative by conventional methods, released Bd zoospores into collection containers and thus must be considered infected. Infection loads determined from filtered water were at least 1000 times higher than those estimated from swabs. Subjects significantly varied in infection load, as they intermittently released zoospores, over a 5-day period. Thus, the method might be used to compare the infectivity of individuals and study the periodicity of zoospore release. Sampling methods based on water filtration can dramatically increase the capacity to accurately diagnose chytridiomycosis and contribute to a better understanding of the interactions between Bd and its hosts.

  12. CRN13 candidate effectors from plant and animal eukaryotic pathogens are DNA-binding proteins which trigger host DNA damage response.

    Science.gov (United States)

    Ramirez-Garcés, Diana; Camborde, Laurent; Pel, Michiel J C; Jauneau, Alain; Martinez, Yves; Néant, Isabelle; Leclerc, Catherine; Moreau, Marc; Dumas, Bernard; Gaulin, Elodie

    2016-04-01

    To successfully colonize their host, pathogens produce effectors that can interfere with host cellular processes. Here we investigated the function of CRN13 candidate effectors produced by plant pathogenic oomycetes and detected in the genome of the amphibian pathogenic chytrid fungus Batrachochytrium dendrobatidis (BdCRN13). When expressed in Nicotiana, AeCRN13, from the legume root pathogen Aphanomyces euteiches, increases the susceptibility of the leaves to the oomycete Phytophthora capsici. When transiently expressed in amphibians or plant cells, AeCRN13 and BdCRN13 localize to the cell nuclei, triggering aberrant cell development and eventually causing cell death. Using Förster resonance energy transfer experiments in plant cells, we showed that both CRN13s interact with nuclear DNA and trigger plant DNA damage response (DDR). Mutating key amino acid residues in a predicted HNH-like endonuclease motif abolished the interaction of AeCRN13 with DNA, the induction of DDR and the enhancement of Nicotiana susceptibility to P. capsici. Finally, H2AX phosphorylation, a marker of DNA damage, and enhanced expression of genes involved in the DDR were observed in A. euteiches-infected Medicago truncatula roots. These results show that CRN13 from plant and animal eukaryotic pathogens promotes host susceptibility by targeting nuclear DNA and inducing DDR. PMID:26700936

  13. Amphibian immune defenses against chytridiomycosis: impacts of changing environments.

    Science.gov (United States)

    Rollins-Smith, Louise A; Ramsey, Jeremy P; Pask, James D; Reinert, Laura K; Woodhams, Douglas C

    2011-10-01

    Eco-immunology is the field of study that attempts to understand the functions of the immune system in the context of the host's environment. Amphibians are currently suffering devastating declines and extinctions in nearly all parts of the world due to the emerging infectious disease chytridiomycosis caused by the chytrid fungus, Batrachochytrium dendrobatidis. Because chytridiomycosis is a skin infection and remains confined to the skin, immune defenses of the skin are critical for survival. Skin defenses include secreted antimicrobial peptides and immunoglobulins as well as antifungal metabolites produced by symbiotic skin bacteria. Low temperatures, toxic chemicals, and stress inhibit the immune system and may impair natural defenses against B. dendrobatidis. Tadpoles' mouth parts can be infected by B. dendrobatidis. Damage to the mouth parts can impair growth, and the affected tadpoles maintain the pathogen in the environment even when adults have dispersed. Newly metamorphosing frogs appear to be especially vulnerable to infection and to the lethal effects of this pathogen because the immune system undergoes a dramatic reorganization at metamorphosis, and postmetamorphic defenses are not yet mature. Here we review our current understanding of amphibian immune defenses against B. dendrobatidis and the ability of the pathogen to resist those defenses. We also briefly review what is known about the impacts of temperature, environmental chemicals, and stress on the host-pathogen interactions and suggest future directions for research. PMID:21816807

  14. The contribution of skin antimicrobial peptides to the system of innate immunity in anurans.

    Science.gov (United States)

    Conlon, J Michael

    2011-01-01

    Cationic peptides with the propensity to adopt an amphipathic α-helical conformation in a membrane-mimetic environment are synthesized in the skins of many species of anurans (frogs and toads). These peptides frequently display cytolytic activities against a range of pathogenic bacteria and fungi consistent with the idea that they play a role in the host's system of innate immunity. However, the importance of the peptides in the survival strategy of the animal is not clearly understood. It is a common misconception that antimicrobial peptides are synthesized in the skins of all anurans. In fact, the species distribution is sporadic suggesting that their production may confer some evolutionary advantage to the organism but is not necessary for survival. Although growth inhibitory activity against the chytrid fungus Batrachochytrium dendrobatidis, responsible for anuran population declines worldwide, has been demonstrated in vitro, the ability of frog skin antimicrobial peptides to protect the animal in the wild appears to be limited and there is no clear correlation between their production by a species and its resistance to fatal chytridiomycosis. The low potency of many frog skin antimicrobial peptides is consistent with the hypothesis that cutaneous symbiotic bacteria may provide the major system of defense against pathogenic microorganisms in the environment with antimicrobial peptides assuming a supplementary role in some species. PMID:20640445

  15. Population recovery following decline in an endangered stream-breeding frog (Mixophyes fleayi from subtropical Australia.

    Directory of Open Access Journals (Sweden)

    David Alan Newell

    Full Text Available Amphibians have undergone dramatic declines and extinctions worldwide. Prominent among these have been the stream-breeding frogs in the rainforests of eastern Australia. The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd has been postulated as the primary cause of these declines. We conducted a capture-mark-recapture study over a 7-year period on the endangered Fleay's barred frog (Mixophyes fleayi at two independent streams (30 km apart in order to assess the stability of these populations. This species had undergone a severe decline across its narrow geographic range. Mark-recapture modelling showed that the number of individuals increased 3-10 fold along stream transects over this period. Frog detection probabilities were frequently above 50% but declined as the populations increased. Adult survival was important to overall population persistence in light of low recruitment events, suggesting that longevity may be a key factor in this recovery. One male and female were present in the capture record for >6 years. This study provides an unambiguous example of population recovery in the presence of Bd.

  16. The demography of Atelopus decline: Harlequin frog survival and abundance in central Panama prior to and during a disease outbreak

    Directory of Open Access Journals (Sweden)

    Rebecca McCaffery

    2015-07-01

    Full Text Available Harlequin frogs (Bufonidae: Atelopus are a species-rich genus of Neotropical toads that have experienced disproportionately severe population declines and extinctions caused by the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd. The genus Atelopus is of high conservation concern, but relatively little is known about the population dynamics and life history of the majority of species. We examined the demography of one population of Atelopus zeteki and two populations of A. varius in central Panama using three to six years of mark-recapture data collected prior to and during an outbreak of Bd. We estimated male survival probabilities prior to the arrival of Bd and sex-specific population sizes for these three populations using state-space Bayesian population models. Prior to the arrival of Bd, monthly apparent survival probabilities were higher for A. varius males than for A. zeteki males, and recaptures among years were low in both species. Abundance of both species varied over time and declined rapidly after the arrival of Bd. Male densities were generally greater than female densities, though female densities were higher or equivalent to males after the arrival of Bd. Estimates of survival and abundance over time may be explained by differences in the use of stream habitat by the two sexes and three populations, both during and between breeding seasons. These estimates provide key baseline population information that can be used to inform reintroductions from captive assurance colonies and studies of extant Atelopus populations as part of conservation and management programs.

  17. Antiviral activity of Inonotus obliquus fungus extract towards infection caused by hepatitis C virus in cell cultures.

    Science.gov (United States)

    Shibnev, V A; Mishin, D V; Garaev, T M; Finogenova, N P; Botikov, A G; Deryabin, P G

    2011-09-01

    Fractions of Inonotus obliquus fungus water extract exhibited a virucidal effect towards hepatitis C virus: it 100-fold reduced its infective properties within 10 min. The antiviral effects of fungus extracts manifested after preventive (24 h before infection) and therapeutic use (during infection of porcine embryo kidney cells). Moreover, the data indicate that the birch fungus extracts inhibit production of infective virus by porcine embryo kidney cells. PMID:22462058

  18. Nest Enlargement in Leaf-Cutting Ants: Relocated Brood and Fungus Trigger the Excavation of New Chambers

    OpenAIRE

    Daniela Römer; Flavio Roces

    2014-01-01

    During colony growth, leaf-cutting ants enlarge their nests by excavating tunnels and chambers housing their fungus gardens and brood. Workers are expected to excavate new nest chambers at locations across the soil profile that offer suitable environmental conditions for brood and fungus rearing. It is an open question whether new chambers are excavated in advance, or will emerge around brood or fungus initially relocated to a suitable site in a previously-excavated tunnel. In the laboratory,...

  19. Nothing Special in the Specialist? Draft Genome Sequence of Cryomyces antarcticus, the Most Extremophilic Fungus from Antarctica

    OpenAIRE

    Katja Sterflinger; Ksenija Lopandic; Ram Vinay Pandey; Barbara Blasi; Albert Kriegner

    2014-01-01

    The draft genome of the Antarctic endemic fungus Cryomyces antarcticus is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with Neurospora crassa as well as wit...

  20. Chemical changes of kraft lignin and some enzymes produced by the white-rot fungus Coriolopsis Gallica

    OpenAIRE

    Gómez Alarcón, Gonzalo; Sáiz-Jiménez, Cesáreo; Lahoz, Rafael; O'Connor, A

    1987-01-01

    The excretion of extracellular enzymes and the degradation of indulin (pine kraft lignin) by the fungus Coriolopsis gallica were studied. By using a lignin-impregnated glass fibre disc which simulated natural conditions, the fungus excreted phenol oxidases during the log phase of growth and reached two activity maxima in the autolytic phase. However, in absence of indulin the fungus had a different behaviour with respect to phenol oxidases. It was concluded that in the ex...

  1. Fungi of Coconut (Cocos nucifera L.)-Their Deteriorative Ability, Quality Stability and the Role of the Fungus-Eating Insects

    Science.gov (United States)

    Chuku, E. C.; Ogbalu, O. K.; Osakwe, J. A.

    Studies on the deteriorative ability and quality stability of coconut (Cocos nucifera L.) and the effect of the fungus-eating insects (Necrobia rufipes, Alphitobius diaperinus, Crematogaster sp. and Tenebrio molitor) were carried out in the Post Graduate Entomology and Plant Pathology Laboratories of the Department of Applied and Environmental Biology and also in Food Science Laboratory of the Rivers State University of Science and Technology, Port Harcourt. Results showed Aspergillus niger van Tieghem, Rhizopus stolonifer Lind and Penicillium italiucum Wehmer as the seed-borne fungi of coconut. Frequency of occurrence was 80% for Aspergillus niger and 100% for both Rhizopus stolonifer and Penicillium italicum. On storage stability, heat drying offered significantly higher protection to coconut copra. Percentage consumption of fungal hyphae by the fungus-eating insects varied with Tenebrio molitor consuming 100% of the three aforementioned fungi. A. diaperinius contributed up to 84.1% reduction of A. niger as against 80.3% reduction by Necrobia rufipes of A. niger, Crematogaster sp. offered the least reduction (64.2%).

  2. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

    Directory of Open Access Journals (Sweden)

    Takken Willem

    2010-01-01

    Full Text Available Abstract Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density, fungus (species and concentration and environmental effects (exposure duration and food availability influence larval mortality caused by fungus, was studied. Methods Laboratory bioassays were performed on the larval stages of Anopheles gambiae and Anopheles stephensi with spores of two fungus species, Metarhizium anisopliae and Beauveria bassiana. For various larval and fungal characteristics and environmental effects the time to death was determined and survival curves established. These curves were compared by Kaplan Meier and Cox regression analyses. Results Beauveria bassiana and Metarhizium anisopliae caused high mortality of An. gambiae and An. stephensi larvae. However, Beauveria bassiana was less effective (Hazard ratio (HR Metarhizium anisopliae. Anopheles stephensi and An. gambiae were equally susceptible to each fungus. Older larvae were less likely to die than young larvae (HR Conclusions This study shows that both fungus species have potential to kill mosquitoes in the larval stage, and that mortality rate depends on fungus species itself, larval stage targeted, larval density and amount of nutrients available to the larvae. Increasing the concentration of fungal spores or reducing the exposure time to spores did not show a proportional increase and decrease in mortality rate, respectively, because the spores clumped together. As a result spores did not provide uniform coverage over space and time. It is, therefore, necessary to develop a formulation that allows the spores to spread over the water surface. Apart from formulation appropriate delivery methods are also necessary to avoid exposing non-target organisms to fungus.

  3. Characterization of fungus-specific microsatellite markers in the lichen-forming fungus Parmelina carporrhizans (Parmeliaceae)1

    Science.gov (United States)

    Alors, David; Dal Grande, Francesco; Schmitt, Imke; Kraichak, Ekaphan; Lumbsch, H. Thorsten; Crespo, Ana; Divakar, Pradeep K.

    2014-01-01

    • Premise of the study: Microsatellite loci were developed to study the lichen-forming fungus Parmelina (Parmeliaceae) in different habitats of western Europe and the Mediterranean for baseline studies to understand the effects of climate change on its distribution. • Methods and Results: We cultured P. carporrhizans from ascospores for genomic sequencing with Illumina HiSeq. We successfully developed 11 polymorphic microsatellite markers and associated primer sets and assessed them with 30 individuals from two of the Canary Islands. The average number of alleles per locus was 8.8. Nei’s unbiased gene diversity of these loci ranged from 0.53 to 0.91 in the tested populations. Amplification in two closely related species (P. tiliacea, P. cryptotiliacea) yielded only limited success. • Conclusions: The new microsatellite markers will allow the study of genetic diversity and population structure in P. carporrhizans. We propose eight markers to combine in two multiplex reactions for further studies on a larger set of populations. PMID:25506522

  4. [Kinetics model for batch culture of white rot fungus].

    Science.gov (United States)

    Xiong, Xiao-ping; Wen, Xiang-hua; Xu, Kang-ning; Bian, Bing-hui

    2008-02-01

    In order to understand ligninolytic enzymes production process during culture of white rot fungus, accordingly to direct the design of fermentation process, a kinetics model was built for the batch culture of Phanerochaete chrysosporium. The parameters in the model were calibrated based on the experimental data from free and immobilized culture separately. The difference between each variable's values calculated based on kinetics model and experimental data is within 15%. Comparing parameters for the free and the immobilized culture, it is found that maximum biomass concentrations are both 1.78 g/L; growth rate ratio of immobilized culture (0.6683 d(-1)) is larger than that of free culture (0.5144 d(-1)); very little glucose is consumed for biomass growth in free culture while in immobilized culture much glucose is used and ammonium nitrogen is consumed at a greater rate. Ligninolytic enzymes production process is non-growth related; fungal pellets can produce MnP (231 U/L) in free culture with a production rate of 115.8 U x (g x d)(-1) before peak and 26.1 U x (g x d)(-1) after peak, thus fed-batch is a possible mode to improve MnP production and fermentation efficiency. MnP (410 U/L) and LiP (721 U/L) can be produced in immobilized culture, but MnP and LiP production rate decrease from 80.1 U x (g x d)(-1) and 248.9 U x (g x d)(-1) to 6.04 U x (g x d)(-1) and 0 U x (g x d)(-1), respectively, indicating a proper feed moment is before the enzymes peak during fed-batch culture. PMID:18613526

  5. Genes involved in virulence of the entomopathogenic fungus Beauveria bassiana.

    Science.gov (United States)

    Valero-Jiménez, Claudio A; Wiegers, Harm; Zwaan, Bas J; Koenraadt, Constantianus J M; van Kan, Jan A L

    2016-01-01

    Pest insects cause severe damage to global crop production and pose a threat to human health by transmitting diseases. Traditionally, chemical pesticides (insecticides) have been used to control such pests and have proven to be effective only for a limited amount of time because of the rapid spread of genetic insecticide resistance. The basis of this resistance is mostly caused by (co)dominant mutations in single genes, which explains why insecticide use alone is an unsustainable solution. Therefore, robust solutions for insect pest control need to be sought in alternative methods such as biological control agents for which single-gene resistance is less likely to evolve. The entomopathogenic fungus Beauveria bassiana has shown potential as a biological control agent of insects, and insight into the mechanisms of virulence is essential to show the robustness of its use. With the recent availability of the whole genome sequence of B. bassiana, progress in understanding the genetics that constitute virulence toward insects can be made more quickly. In this review we divide the infection process into distinct steps and provide an overview of what is currently known about genes and mechanisms influencing virulence in B. bassiana. We also discuss the need for novel strategies and experimental methods to better understand the infection mechanisms deployed by entomopathogenic fungi. Such knowledge can help improve biocontrol agents, not only by selecting the most virulent genotypes, but also by selecting the genotypes that use combinations of virulence mechanisms for which resistance in the insect host is least likely to develop. PMID:26628209

  6. Distribution pattern and maintenance of ectomycorrhizal fungus diversity

    Directory of Open Access Journals (Sweden)

    Cheng Gao

    2013-07-01

    Full Text Available Ectomycorrhiza (ECM are symbionts formed between soil fungi and plant root systems, in which the fungus exchanges soil-derived nutrients for carbohydrates obtained from the host plant. As an important component of terrestrial ecosystems, ECM fungi can play an essential role in biodiversity maintenance and plant community succession. Understanding the distribution pattern and maintenance of ECM fungal diversity is therefore critical to the study of biodiversity and ecosystem functioning. An analysis of results of recent research indicates that ECM fungal diversity increases with increasing latitude, i.e. from tropical to subtropical and temperate regions. The role of dispersal in ECM fungal distribution is dependent on spatial scale. Thus, it has been found to be weak across global and local scales, but strong at regional and small scales. At the local scale, its influence has also been shown to be host-dominant dependent; thus, it is important in host non-dominant ecosystems, but not in host dominant ecosystems. Selection by plant, animal, microbe and abiotic factors can also affect the distribution pattern of ECM fungi, according to studies of temperate ecosystems. In contrast, studies of tropical ecosystems indicate that selection on ECM fungal distribution can be either strong or weak. ECM fungal diversity is also influenced by plant diversity and productivity. The plant diversity hypothesis at host genus-level fits well with ECM fungal diversity in temperate, subtropical and tropical forest ecosystems; in contrast, the productivity diversity hypothesis is only supported by some studies in temperate forest ecosystems. We propose that future studies should focus on the distribution pattern, maintenance mechanism and ecosystem function of ECM fungal diversity at a global scale, taking account ofscenarios of global climate change.

  7. Toxicity of graphene oxide to white rot fungus Phanerochaete chrysosporium.

    Science.gov (United States)

    Xie, Jingru; Ming, Zhu; Li, Hongliang; Yang, Hua; Yu, Baowei; Wu, Ruihan; Liu, Xiaoyang; Bai, Yitong; Yang, Sheng-Tao

    2016-05-01

    With the wide production and applications of graphene and its derivatives, their toxicity to the environment has received much attention nowadays. In this study, we investigated the toxicity of graphene oxide (GO) to white rot fungus (Phanerochaete chrysosporium). GO was prepared by modified Hummers method and well characterized before use. P. chrysosporium was exposed to GO at the concentrations of 0-4 mg/mL for 7 d. The fresh and dry weights, pH values of culture media, structures, ultrastructures, IR spectra and activities of the decomposition of pollutants were measured to reveal the hazards of GO to P. chrysosporium. Our results indicated that low concentrations of GO stimulated the growth of P. chrysosporium. The exposure to GO induced more acidic pH values of the culture media after 7 d. GO induced the disruption of the fiber structure of P. chrysosporium, while at 4 mg/mL some very long and thick fibers were formed. Such changes were reflected in the scanning electron microscopy investigations, where the disruption of fibers was observed. In the ultrastructural investigations, the shape of P. chrysosporium cells changed and more vesicles were found upon the exposure to GO. The infrared spectroscopy analyses suggested that the chemical compositions of mycelia were not changed qualitatively. Beyond the toxicity, GO did not alter the activities of P. chrysosporium at low concentrations, but led to the complete loss of activity at high concentrations. The implication to the ecological safety of graphene is discussed. PMID:26950023

  8. Pathogenic fungus Microsporum canis activates the NLRP3 inflammasome.

    Science.gov (United States)

    Mao, Liming; Zhang, Liping; Li, Hua; Chen, Wei; Wang, Hongbin; Wu, Shuxian; Guo, Caiqin; Lu, Ailing; Yang, Guiwen; An, Liguo; Abliz, Paride; Meng, Guangxun

    2014-02-01

    Microsporum canis is a pathogenic fungus with worldwide distribution that causes tinea capitis in animals and humans. M. canis also causes invasive infection in immunocompromised patients. To defy pathogenic fungal infection, the host innate immune system is the first line of defense. As an important arm of innate immunity, the inflammasomes are intracellular multiprotein complexes that control the activation of caspase-1, which cleaves proinflammatory cytokine pro-interleukin-1β (IL-1β) into its mature form. To determine whether the inflammasome is involved in the host defense against M. canis infection, we challenged human monocytic THP-1 cells and mouse dendritic cells with a clinical strain of M. canis isolated from patients with tinea capitis. We found that M. canis infection triggered rapid secretion of IL-1β from both THP-1 cells and mouse dendritic cells. Moreover, by using gene-specific shRNA and competitive inhibitors, we determined that M. canis-induced IL-1β secretion was dependent on NLRP3. The pathways proposed for NLRP3 inflammasome activation, namely, cathepsin B activity, K(+) efflux, and reactive oxygen species production, were all required for the inflammasome activation triggered by M. canis. Meanwhile, Syk, Dectin-1, and Card9 were found to be involved in M. canis-induced IL-1β secretion via regulation of pro-IL-1β transcription. More importantly, our data revealed that M. canis-induced production of IL-1β was dependent on the NLRP3 inflammasome in vivo. Together, this study unveils that the NLRP3 inflammasome exerts a critical role in host innate immune responses against M. canis infection, and our data suggest that diseases that result from M. canis infection might be controlled by regulating the activation of inflammasomes. PMID:24478101

  9. Palaeoanellus dimorphus gen. et sp. nov. (Deuteromycotina): a Cretaceous predatory fungus.

    Science.gov (United States)

    Schmidt, Alexander R; Dörfelt, Heinrich; Perrichot, Vincent

    2008-10-01

    In habitats where nitrogen is the limiting factor, carnivorous fungi gain an advantage by preying on nematodes and other microorganisms. These fungi are abundant in modern terrestrial ecosystems, but they are not predestined for preservation as fossils. Conclusions on their evolutionary history are therefore mainly based on molecular studies that are generally limited to those taxa that have survived until today. Here we present a fossil dimorphic fungus that was found in Late Albian amber from southwestern France. This fungus possessed unicellular hyphal rings as trapping devices and formed blastospores from which a yeast stage developed. The fossil probably represents an anamorph of an ascomycete and is described as Palaeoanellus dimorphus gen. et sp. nov. Because predatory fungi with regular yeast stages are not known from modern ecosystems, the fungus is assumed to not be related to any Recent carnivorous fungus and to belong to an extinct lineage of carnivorous fungi. The inclusions represent the only record of fossil fungi that developed trapping devices, so far. The fungus lived c. 100 million years ago in a limnetic-terrestrial microhabitat, and it was a part of a highly diverse biocenosis at the forest floor of a Cretaceous coastal amber forest. PMID:21632336

  10. Combining microtomy and confocal laser scanning microscopy for structural analyses of plant-fungus associations.

    Science.gov (United States)

    Rath, Magnus; Grolig, Franz; Haueisen, Janine; Imhof, Stephan

    2014-05-01

    The serious problem of extended tissue thickness in the analysis of plant-fungus associations was overcome using a new method that combines physical and optical sectioning of the resin-embedded sample by microtomy and confocal microscopy. Improved tissue infiltration of the fungal-specific, high molecular weight fluorescent probe wheat germ agglutinin conjugated to Alexa Fluor® 633 resulted in high fungus-specific fluorescence even in deeper tissue sections. If autofluorescence was insufficient, additional counterstaining with Calcofluor White M2R or propidium iodide was applied in order to visualise the host plant tissues. Alternatively, the non-specific fluorochrome acid fuchsine was used for rapid staining of both, the plant and the fungal cells. The intricate spatial arrangements of the plant and fungal cells were preserved by immobilization in the hydrophilic resin Unicryl™. Microtomy was used to section the resin-embedded roots or leaves until the desired plane was reached. The data sets generated by confocal laser scanning microscopy of the remaining resin stubs allowed the precise spatial reconstruction of complex structures in the plant-fungus associations of interest. This approach was successfully tested on tissues from ectomycorrhiza (Betula pendula), arbuscular mycorrhiza (Galium aparine; Polygala paniculata, Polygala rupestris), ericoid mycorrhiza (Calluna vulgaris), orchid mycorrhiza (Limodorum abortivum, Serapias parviflora) and on one leaf-fungus association (Zymoseptoria tritici on Triticum aestivum). The method provides an efficient visualisation protocol applicable with a wide range of plant-fungus symbioses. PMID:24249491

  11. Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens

    Energy Technology Data Exchange (ETDEWEB)

    Aylward, Frank O.; Burnum, Kristin E.; Scott, Jarrod J.; Suen, Garret; Tringe, Susannah G.; Adams, Sandra M.; Barry, Kerrie W.; Nicora, Carrie D.; Piehowski, Paul D.; Purvine, Samuel O.; Starrett, Gabriel J.; Goodwin, Lynne A.; Smith, Richard D.; Lipton, Mary S.; Currie, Cameron R.

    2012-09-01

    Herbivores gain access to nutrients stored in plant biomass largely by harnessing the metabolic activities of microbes. Leaf-cutter ants of the genus Atta are a hallmark example; these dominant Neotropical herbivores cultivate symbiotic fungus gardens on massive quantities of fresh plant forage. As the external digestive system of the ants, fungus gardens facilitate the production and sustenance of millions of workers in mature Atta colonies. Here we use metagenomic, and metaproteomic techniques to characterize the bacterial diversity and overall physiological potential of fungus gardens from two species of Atta. Our analysis of over 1.2 Gbp of community metagenomic sequence and three 16S pyrotag libraries reveals that, in addition to harboring the dominant fungal crop, these ecosystems contain abundant populations of Enterobacteriaceae, including the genera Enterobacter, Pantoea, Klebsiella, Citrobacter, and Escherichia. We show that these bacterial communities possess genes commonly associated with lignocellulose degradation, and likely participate in the processing of plant biomass. Additionally, we demonstrate that bacteria in these environments encode a diverse suite of biosynthetic pathways, and that they may enrich the nitrogen-poor forage of the ants with B-vitamins, amino acids, and proteins. These results are consistent with the hypothesis that fungus gardens are highly-specialized fungus-bacteria communities that efficiently convert plant material into usable energy for their ant hosts. Together with recent investigations into the microbial symbionts of vertebrates, our work underscores the importance of microbial communities to the ecology and evolution of herbivorous metazoans.

  12. Effect of growing media and their constituents on fungus gnat, Bradysia sp. nr. coprophila (Lintner) adults

    Institute of Scientific and Technical Information of China (English)

    RAYMOND A. CLOYD; AMY DICKINSON; RICHARD A. LARSON; KAREN A.MARLEY

    2007-01-01

    This study was conducted to determine the attractiveness of two growing media,commonly utilized in greenhouses, to fungus gnat, Bradysia sp. nr. coprophila adults. The constituents of the most attractive growing medium tested were determined by gas chromatography analysis using a steam-distillation procedure. We found that fungus gnat adults were more attracted to the growing medium, SB300 Universal Professional Growing Mix,which contains composted bark, than to another growing medium (Sunshine LC1 Mix) and their components when tested in a series of laboratory experiments using multiple-choice experimental arenas. A higher percentage of fungus gnat adults were attracted to moist SB300(92%)than SB300 growing medium that had been oven dried (8%). In addition,fungus gnat adults preferred SB300 although they had been reared on Sunshine LC1 Mix.When comparing the SB300 fresh from the bag to growing medium that had been pasteurized and moistened with water, gas chromatographic-mass spectroscopic data showed there were declines in several terpenoid constituents as well as an increase in fatty acids and cyclosulfur.The results of this study indicate that B. sp. nr. coprophila adults prefer certain growing media, which may assist greenhouse producers in managing fungus gnats in crop production systems.

  13. Evaluation of the bioremediation ability of the isolated white rot fungus on the textile effluents

    Directory of Open Access Journals (Sweden)

    Indira Priyadarsini* R

    2012-08-01

    Full Text Available Every one contributes to the environmental pollution by theiractivities either directly or indirectly and it is our moral responsibility to uncover a solution in order to come out of it also. Hence an attempt was made to isolate a white rot fungus with better remediation ability. The white rot fungus was isolated from decay wood sample and identified as Trametes hirsuta by molecular identification methods. The assessment of the bioremediation ability of the isolated organism was done with four textile effluent samples and the physico-chemical parameters namely colour, pH, TSS, TDS, COD, BOD, Total Hardness, level of Calcium, Magnesium, Chloride and Sulphate were evaluated. The change in the initial pH values of the four textile effluents after treatment with the isolated organism was not significant. All the other parameters were found to be reduced from their respective initial level after treatment with the isolated white rot fungus.

  14. Parasitic and Saprophytic Abilities of the Nematode-Attacking Fungus Hirsutella rhossiliensis.

    Science.gov (United States)

    Jaffee, B A; Zehr, E I

    1985-07-01

    The ability of Hirsutella rhossiliensis to colonize various substrates in sterile and nonsterile soil was measured. Hirsutella rhossiliensis was recovered from 67% and 77% of living, inoculated Criconemella xenoplax incubated in sterile and nonsterile soil, respectively. In contrast, the fungus was recovered from 100% and 18% of heat-killed, inoculated nematodes incubated on sterile and nonsterile soil, respectively. Hirsutella rhossiliensis was readily recovered from inoculated, autoclaved wheat seeds incubated in sterile soil but not from seeds incubated in nonsterile soil. Autoclaved peach roots were a poor substrate for the fungus. Germination of H. rhossiliensis spores incubated on agar disks above soil was about 90% regardless of soil treatment. However, germ tube length was greatly suppressed by nonsterile soil. Our results suggest that H. rhossiliensis is a better parasite than saprophyte and that the fungus may be specialized for attacking nematodes. PMID:19294104

  15. Painful Bladder Syndrome: An Unusual Presentation in a Case of Upper Tract Fungus Balls.

    Science.gov (United States)

    Bajic, Petar; Wetterlin, Jessica; Bresler, Larissa

    2016-05-01

    Urinary tract fungus balls are a rare pathologic entity which may be asymptomatic or have variable presentations. To date, there have been no documented cases of fungus balls presenting as painful bladder syndrome. Painful bladder syndrome is a constellation of symptoms which may include pelvic pain, urgency and frequency not explained by other causes. Here, we present the first case of these two entities concurrently. Our patient had a longstanding history of diabetes, nephrolithiasis and recurrent urinary tract infections. He presented with symptoms of painful bladder syndrome and work-up revealed filling defects within the renal collecting system concerning for malignancy. Subsequent ureteroscopy revealed dense white debris consistent with candida fungus balls. Following clearance of the debris and antifungal therapy, our patient has remained asymptomatic. PMID:27390583

  16. Exploring the potential for actinobacteria as defensive symbionts in fungus-growing termites

    DEFF Research Database (Denmark)

    Visser, Anna A.; Nobre, Tânia; Currie, Cameron R.;

    2012-01-01

    for morphological (288 isolates, grouped in 44 morphotypes) and for 16S rRNA (35 isolates, spanning the majority of morphotypes) characterisation. Actinobacteria were found throughout all sampled nests and colony parts and, phylogenetically, they are interspersed with Actinobacteria from origins other than fungus...... a role as defensive symbionts against Pseudoxylaria in fungus-growing termites. We sampled for Actinobacteria from 30 fungus-growing termite colonies, spanning the three main termite genera and two geographically distant sites. Our isolations yielded 360 Actinobacteria, from which we selected subsets......-growing termites, indicating lack of specificity. Antibiotic-activity screening of 288 isolates against the fungal cultivar and competitor revealed that most of the Actinobacteria-produced molecules with antifungal activity. A more detailed bioassay on 53 isolates, to test the specificity of antibiotics, showed...

  17. Malassezia furfur: a fungus belonging to the physiological skin flora and its relevance in skin disorders.

    Science.gov (United States)

    Schmidt, A

    1997-01-01

    Malassezia furfur is an anthropophilic fungus that belongs to the physiological skin flora. The fungus can grow in a yeast phase as well as in a mycelial phase; on nonaffected skin the fungus is mainly prevalent in the yeast phase. The organism has complex lipid requirements for growth, which also explains its occurrence on the skin. This also leads to the requirement for specially supplemented media for in vitro cultivation. Malassezia furfur is the causative agent of pityriasis versicolor. It also seems to be associated with seborrheic dermatitis and dandruff formation, folliculitis, confluent and reticulate papillomatosis, and the provocation of psoriatic lesions. Many substances for topical application, such as azole antimycotics, ciclopirox olamine, piroctone-olamine, zinc pyrithione, or sulfur-containing substances are effective in the treatment of these diseases. In recent years rare cases of systemic infections and fungemias caused by Malassezia have been reported. PMID:9013067

  18. Direct ethanol production from starch, wheat bran and rice straw by the white rot fungus Trametes hirsuta

    NARCIS (Netherlands)

    Okamoto, Kenji; Nitta, Yasuyuki; Maekawa, Nitaro; Yanase, Hideshi

    2011-01-01

    The white rot fungus Trametes hirsuta produced ethanol from a variety of hexoses: glucose, mannose, cellobiose and maltose, with yields of 0.49. 0.48, 0.47 and 0.47 g/g of ethanol per sugar utilized, respectively. In addition, this fungus showed relatively favorable xylose consumption and ethanol pr

  19. An ultrastructural study of cell-cell interactions in capture organs of the nematophagous fungus Arthrobotrys oligospora

    NARCIS (Netherlands)

    Veenhuis, Marten; Nordbring-Hertz, Birgit; Harder, Willem

    1985-01-01

    A detailed ultrastructural analysis was made of interactions between individual cells within the same adhesive network (trap) of the nematophagous fungus Arthrobotrys oligospora. These interactions were confined to traps which had captured nematodes, and occurred concurrently with the fungus-nematod

  20. Pseudoxylaria as stowaway of the fungus-growing termite nest: Interaction asymmetry between Pseudoxylaria, Termitomyces and free-living relatives.

    NARCIS (Netherlands)

    Visser, A.A.; Kooij, P.W.; Debets, A.J.M.; Kuyper, T.W.; Aanen, D.K.

    2011-01-01

    Though inconspicuous in healthy nests, Pseudoxylaria species are almost always present and overgrow deteriorating fungus-growing termite gardens. Whether these fungi are detrimental to the fungus-garden, benign, or even beneficial is unclear. We hypothesize that Pseudoxylaria is a stowaway that prac

  1. Decolorization of reactive brilliant red K-2BP by white rot fungus under sterile and non-sterile conditions

    Institute of Scientific and Technical Information of China (English)

    GAO Da-wen; WEN Xiang-hua; QIAN Yi

    2006-01-01

    Almost all the studies both domestic and international using white rot fungus for dye wastewater treatment are performed under sterile conditions. However, it is obviously unpractical that wastewater with dyes is treated under sterile conditions. A feasible study was made for using white rot fungus Phanerochaete chrysosporium to degrade reactive brilliant red K-2BP dye under non-sterile conditions. The results showed that there was no decolorizing effect under non-sterile condition if white rot fungus was incubated under non-sterile condition, and the decolorization was always near to 0% during decolorizing test for 3 d; in the meantime, a lot of yeast funguses were found in liquid medium when white rot fungus was incubated under non-sterile conditions; however, if white rot fungus was incubated under sterile condition firstly, its decolorization was above 90% under non-sterile condition, which was similar to that of sterile condition. So we point out that the treating process for wastewater with dyes should be divided into two stages. The first stage is that white rot fungus should be incubated under sterile conditions, and the second stage is that reactive brilliant red K-2BP is decolorized under non-sterile conditions. The method not only save the operation cost which decolorizing reactive brilliant red K-2BP under sterile condition, but also provide the feasibility for using white rot fungus to degrade wastewater with dyes under non-sterile conditions.

  2. Draft Genome Sequence of the Plant-Pathogenic Soil Fungus Rhizoctonia solani Anastomosis Group 3 Strain Rhs1AP

    OpenAIRE

    Cubeta, Marc A.; Thomas, Elizabeth; Dean, Ralph A.; Jabaji, Suha; Neate, Stephen M.; Tavantzis, Stellos; Toda, Takeshi; Vilgalys, Rytas; Bharathan, Narayanaswamy; Fedorova-Abrams, Natalie; Pakala, Suman B.; Pakala, Suchitra M.; Zafar, Nikhat; Joardar, Vinita; Losada, Liliana

    2014-01-01

    The soil fungus Rhizoctonia solani is a pathogen of agricultural crops. Here, we report on the 51,705,945 bp draft consensus genome sequence of R. solani strain Rhs1AP. A comprehensive understanding of the heterokaryotic genome complexity and organization of R. solani may provide insight into the plant disease ecology and adaptive behavior of the fungus.

  3. Gamma radiation effects on the frequency of toxigenic fungus on sene (Cassia angustifolia) and green tea (Camelia sinensis) samples

    International Nuclear Information System (INIS)

    The levels of contamination and gamma radiation effects were analyzed in the reduction of toxigenic filamentous fungus in two types of medicinal plants. Aspergillus and Penicillium were the predominant genders and 73,80% of the samples showed high levels of fungus contamination

  4. Extraction of DNA from plant and fungus tissues in situ

    Directory of Open Access Journals (Sweden)

    Abu Almakarem Amal S

    2012-06-01

    Full Text Available Abstract Background When samples are collected in the field and transported to the lab, degradation of the nucleic acids contained in the samples is frequently observed. Immediate extraction and precipitation of the nucleic acids reduces degradation to a minimum, thus preserving accurate sequence information. An extraction method to obtain high quality DNA in field studies is described. Findings DNA extracted immediately after sampling was compared to DNA extracted after allowing the sampled tissues to air dry at 21°C for 48 or 72 hours. While DNA extracted from fresh tissues exhibited little degradation, DNA extracted from all tissues exposed to 21°C air for 48 or 72 hours exhibited varying degrees of degradation. Yield was higher for extractions from fresh tissues in most cases. Four microcentrifuges were compared for DNA yield: one standard electric laboratory microcentrifuge (max rcf = 16,000×g, two battery-operated microcentrifuges (max rcf = 5,000 and 3,000 ×g, and one manually-operated microcentrifuge (max rcf = 120×g. Yields for all centrifuges were similar. DNA extracted under simulated field conditions was similar in yield and quality to DNA extracted in the laboratory using the same equipment. Conclusions This CTAB (cetyltrimethylammonium bromide DNA extraction method employs battery-operated and manually-operated equipment to isolate high quality DNA in the field. The method was tested on plant and fungus tissues, and may be adapted for other types of organisms. The method produced high quality DNA in laboratory tests and under simulated field conditions. The field extraction method should prove useful for working in remote sites, where ice, dry ice, and liquid nitrogen are unavailable; where degradation is likely to occur due to the long distances between the sample site and the laboratory; and in instances where other DNA preservation and transportation methods have been unsuccessful. It may be possible to adapt

  5. Temperature Modulates the Secretome of the Phytopathogenic Fungus Lasiodiplodia theobromae.

    Science.gov (United States)

    Félix, Carina; Duarte, Ana S; Vitorino, Rui; Guerreiro, Ana C L; Domingues, Pedro; Correia, António C M; Alves, Artur; Esteves, Ana C

    2016-01-01

    Environmental alterations modulate host-microorganism interactions. Little is known about how climate changes can trigger pathogenic features on symbiont or mutualistic microorganisms. Current climate models predict increased environmental temperatures. The exposing of phytopathogens to these changing conditions can have particularly relevant consequences for economically important species and for humans. The impact on pathogen/host interaction and the shift on their biogeographical range can induce different levels of virulence in new hosts, allowing massive losses in agricultural and health fields. Lasiodiplodia theobromae is a phytopathogenic fungus responsible for a number of diseases in various plants. It has also been described as an opportunist pathogen in humans, causing infections with different levels of severity. L. theobromae has a high capacity of adaptation to different environments, such as woody plants, moist argillaceous soils, or even humans, being able to grow and infect hosts in a wide range of temperatures (9-39°C). Nonetheless, the effect of an increase of temperature, as predicted in climate change models, on L. theobromae is unknown. Here we explore the effect of temperature on two strains of L. theobromae - an environmental strain, CAA019, and a clinical strain, CBS339.90. We show that both strains are cytotoxic to mammalian cells but while the environmental strain is cytotoxic mainly at 25°C, the clinical strain is cytotoxic mainly at 30 and 37°C. Extracellular gelatinolytic, xylanolytic, amylolytic, and cellulolytic activities at 25 and 37°C were characterized by zymography and the secretome of both strains grown at 25, 30, and 37°C were characterized by electrophoresis and by Orbitrap LC-MS/MS. More than 75% of the proteins were identified, mostly enzymes (glycosyl hydrolases and proteases). The strains showed different protein profiles, which were affected by growth temperature. Also, strain specific proteins were identified, such

  6. Rapid evolution of avirulence genes in rice blast fungus Magnaporthe oryzae

    OpenAIRE

    Huang, Ju; Si, Weina; Deng, Qiming; Li, Ping; Yang, Sihai

    2014-01-01

    Background Rice blast fungus Magnaporthe oryzae is one of the most devastating pathogens in rice. Avirulence genes in this fungus share a gene-for-gene relationship with the resistance genes in its host rice. Although numerous studies have shown that rice blast R-genes are extremely diverse and evolve rapidly in their host populations, little is known about the evolutionary patterns of the Avr-genes in the pathogens. Results Here, six well-characterized Avr-genes and seven randomly selected n...

  7. High Symbiont Relatedness Stabilizes Mutualistic Cooperation in Fungus-Growing Termites

    DEFF Research Database (Denmark)

    Aanen, Duur K; de Fine Licht, Henrik H; Debets, Alfons J M;

    2009-01-01

    studied. We show that African fungus-growing termites propagate single variants of their Termitomyces symbiont, despite initiating cultures from genetically variable spores from the habitat. High inoculation density in the substrate followed by fusion among clonally related mycelia enhances the efficiency...... of spore production in proportion to strain frequency. This positive reinforcement results in an exclusive lifetime association of each host colony with a single fungal symbiont and hinders the evolution of cheating. Our findings explain why vertical symbiont transmission in fungus-growing termites...

  8. Pseudoxylaria as stowaway of the fungus-growing termite nest:

    DEFF Research Database (Denmark)

    Visser, Anna A.; Kooij, Pepijn Wilhelmus; Debets, Alfons J. M.;

    2011-01-01

    Though inconspicuous in healthy nests, Pseudoxylaria species are almost always present and overgrow deteriorating fungus-growing termite gardens. Whether these fungi are detrimental to the fungus-garden, benign, or even beneficial is unclear. We hypothesize that Pseudoxylaria is a stowaway that...... practices a sit-and-wait strategy to survive in the termite nest. Using isolates from three different termite genera to test our hypothesis, we compared Pseudoxylaria’s growth on 40 carbon sources with that of Termitomyces and tested its interaction with Termitomyces. The C-source use of both fungi largely...

  9. Laccase activity from the fungus trametes hirsuta using an air-lift bioreactor

    OpenAIRE

    Rodríguez Couto, S.; Rodríguez, A.; Paterson, R. R. M.; Lima, Nelson; Teixeira, J.A.

    2006-01-01

    Aim: To produce high laccase activities from the white-rot fungus Trametes hirsuta in an in-house air-lift bioreactor (ALB). Methods and Results: Trametes hirsuta was grown in a 6-l ALB. A fed-batch strategy with glycerol as an addition resulted in maximum laccase activity of 19 400 U l)1, which was the highest reported from the fungus. Conclusion: The ALB configuration with additional glycerol resulted in high laccase activities. Significance and Impact of the Study: This study p...

  10. [Antiviral activity of aqueous extracts of the birch fungus Inonotus obliquus on the human immunodeficiency virus].

    Science.gov (United States)

    Shibnev, V A; Garaev, T M; Finogenova, M P; Kalnina, L B; Nosik, D N

    2015-01-01

    Fractions of aqueous and water-alcohol extracts of the birch fungus Inonotus obliquus have antiviral effect against the human immunodeficiency virus type 1 (HIV-1). Antiviral properties of low toxic extracts were manifested in the concentration of 5.0 μg/ml upon simultaneous application with the virus in the lymphoblastoid cells culture MT-4. The extract of the birch fungus can be used for development of new antiviral drugs, inhibitors of HIV-replication when used both in the form of individual drugs and as a part of complex therapy. PMID:26182655

  11. Buwchfawromyces eastonii gen. nov., sp. nov.: a new anaerobic fungus (Neocallimastigomycota isolated from buffalo faeces

    Directory of Open Access Journals (Sweden)

    Tony Martin Callaghan

    2015-03-01

    Full Text Available The novel anaerobic fungus Buwchfawromyces eastonii gen. nov., sp. nov., belonging to order Neocallimastigales (phylum Neocallimastigomycota is described. Morphologically similar to Piromyces but genetically quite distinct, this fungus (isolate GE09 was first isolated from buffalo faeces in west Wales and then subsequently isolated from sheep, cattle and horse in the same area. Phylogenetic analysis of LSU and ITS sequence confirmed that B. eastonii isolates formed a distinct clade close to the polycentric Anaeromyces spp. The morphology of GE09 is monocentric with monoflagellate zoospores. However, the sporangial stalk (sporangiophore is often distinctly swollen and the proximal regions of the rhizoidal system twisted in appearance.

  12. A new guaiane mannoside from a Eutypa-like fungus isolated from Murraya paniculata in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Afonso D.L.; Rodrigues-Filho, Edson [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica; Souza, Antonia Q.L.; Henrique-Silva, Flavio [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Genetica e Evolucao; Pereira, Jose O. [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Fac. de Ciencias Agrarias

    2008-07-01

    A Eutypa-like fungus was isolated from the stems of Murraya paniculata. The fungus was cultivated in liquid medium and produced the new guaiane-type sesquiterpenoid (1R,4S,5S,7R,10R)- 10-hydroxyguaianol 10-O-beta-mannopyranoside and the 3-hydroxy-5-phenylmethyl-(3S,5R)- tetrahydrofuran-2-one, a diastereomer of harzialactone A, obtained for the first time from a natural source. The structures of these metabolites were elucidated based on analysis of their spectroscopic data. (author)

  13. A new eremophilane-type sesquiterpene from the phytopatogen fungus Lasiodiplodia theobromae (Sphaeropsidaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Fatima M.; Oliveira, Maria da Conceicao F. de; Arriaga, Angela M.C.; Lemos, Telma L.G.; Andrade-Neto, Manoel; Mattos, Marcos C. de [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica]. E-mail: mcfo@ufc.br; Mafezoli, Jair [Universidade de Fortaleza, CE (Brazil). Curso de Farmacia; Viana, Francisco M.P.; Ferreira, Viviane M. [EMBRAPA Agroindustria Tropical, Fortaleza, CE (Brazil). Lab. de Fitopatologia; Rodrigues-Filho, Edson; Ferreira, Antonio G. [Universidade Federal de Sa Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2008-07-01

    The phytopatogenic fungus Lasiodiplodia theobromae, isolated from guava, was cultivated in rice for 32 days at room temperature. Extraction with CH{sub 2}Cl{sub 2}:MeOH (3:7), followed by chromatography fractionation of the extract provided ergosterol. From the fungus culture in Czapeck medium for 40 days at room temperature, were isolated isocoumarin cis-4-hydroxymeleine and an eremophilane-type sesquiterpene. The latter compound is being reported for the first time in the literature. Also, this is the first time that an eremophilane sesquiterpene is described for Lasiodiplodia genus. (author)

  14. A new guaiane mannoside from a Eutypa-like fungus isolated from Murraya paniculata in Brazil

    International Nuclear Information System (INIS)

    A Eutypa-like fungus was isolated from the stems of Murraya paniculata. The fungus was cultivated in liquid medium and produced the new guaiane-type sesquiterpenoid (1R,4S,5S,7R,10R)- 10-hydroxyguaianol 10-O-beta-mannopyranoside and the 3-hydroxy-5-phenylmethyl-(3S,5R)- tetrahydrofuran-2-one, a diastereomer of harzialactone A, obtained for the first time from a natural source. The structures of these metabolites were elucidated based on analysis of their spectroscopic data. (author)

  15. Influence of arbuscular mycorrhizal fungus Glomus intra-radices on accumulation of radiocaesium by plant species

    International Nuclear Information System (INIS)

    The role of arbuscular mycorrhizal fungus Glomus intra-radices in 134Cs isotope uptake by different plant species is studied. The impact of radiocaesium on mycorrhizal development and functioning of plant photosynthetic apparatus is considered. The possibility of mycorrhizal symbiosis application in phytoremediation of radioactively contaminated areas is analyzed.It is found that colonization of plants with arbuscular mycorrhizal fungus resulted in significant decrease of radiocaesium concentration in their aboveground parts, while it did not have considerable impact on the radionuclide uptake by plant root system

  16. Influence of arbuscular mycorrhizal fungus Glomus intraradices on accumulation of radiocaesium by plant species

    International Nuclear Information System (INIS)

    The role of arbuscular mycorrhizal fungus Glomus intraradices in 134Cs isotope by different plant species is studied. The impact of radiocaesium on mycorrhizal development and functioning of plant photosynthetic apparatus is considered. The possibility of mycorrhizal symbiosis application in phyto remediation of radioactively contaminated areas is analyzed. It is found that colonization pf plants with arbuscular mycorrhizal fungus resulted in significant decrease of radiocesium concentration in their aboveground parts, while it did not have considerable impact on the radionuclide uptake by plant root system

  17. Caste-specific symbiont policing by workers of Acromyrmex fungus-growing ants

    DEFF Research Database (Denmark)

    Ivens, Aniek B.F.; Nash, David R.; Poulsen, Michael;

    2009-01-01

    and transmission of symbionts. Symbiont transmission is vertical by default, and both the ants and resident fungus actively protect the fungal monoculture growing in their nest against secondary introductions of genetically dissimilar symbionts from other colonies. An earlier study showed that...... mixtures of major and minor Acromyrmex workers eliminate alien fungus fragments even in subcolonies where their resident symbiont is not present. We hypothesize that the different tasks and behaviors performed by majors and minors are likely to select for differential responses to alien fungi. Major...

  18. A virus in a fungus in a plant: Three-way symbiosis required for thermal tolerance

    Science.gov (United States)

    Marquez, L.M.; Redman, R.S.; Rodriguez, R.J.; Roossinck, M.J.

    2007-01-01

    A mutualistic association between a fungal endophyte and a tropical panic grass allows both organisms to grow at high soil temperatures. We characterized a virus from this fungus that is involved in the mutualistic interaction. Fungal isolates cured of the virus are unable to confer heat tolerance, but heat tolerance is restored after the virus is reintroduced. The virus-infected fungus confers heat tolerance not only to its native monocot host but also to a eudicot host, which suggests that the underlying mechanism involves pathways conserved between these two groups of plants.

  19. The research of using Co-60 γ ray to sterilize different mediums for edible fungus

    Science.gov (United States)

    Guozhu, Li; Zhenqian, Guan; Hengshou, Zhao

    1993-10-01

    The present experiment has been carried out by using different dosage of Co—60 γ ray for radiation sterilization of five kinds of cultural materials of edible fungus, The results indicated that sterilization dosage of sawdust is 22 kGy. that of cotton—seed shell and the rest are 26 kGy. We conclude that using Co-60 γ ray to sterilize the cultura 1 materials of edible fungus is a secure and saving labor and energy new method which could sterilize thoroughly.

  20. Ecology of Fungus Gnats (Bradysia spp. in Greenhouse Production Systems Associated with Disease-Interactions and Alternative Management Strategies

    Directory of Open Access Journals (Sweden)

    Raymond A. Cloyd

    2015-04-01

    Full Text Available Fungus gnats (Bradysia spp. are major insect pests of greenhouse-grown horticultural crops mainly due to the direct feeding damage caused by the larvae, and the ability of larvae to transmit certain soil-borne plant pathogens. Currently, insecticides and biological control agents are being used successively to deal with fungus gnat populations in greenhouse production systems. However, these strategies may only be effective as long as greenhouse producers also implement alternative management strategies such as cultural, physical, and sanitation. This includes elimination of algae, and plant and growing medium debris; placing physical barriers onto the growing medium surface; and using materials that repel fungus gnat adults. This article describes the disease-interactions associated with fungus gnats and foliar and soil-borne diseases, and the alternative management strategies that should be considered by greenhouse producers in order to alleviate problems with fungus gnats in greenhouse production systems.

  1. Interaction of Rhizobium sp. with Toxin-Producing Fungus in Culture Medium and in a Tropical Soil †

    Science.gov (United States)

    Habte, Mitiku; Barrion, Melinda

    1984-01-01

    Experiments were conducted to determine the influence of a toxin-producing fungus on a rhizobial population in yeast-mannitol medium and in a tropical soil. The fungus, which was isolated from a highly weathered soil (Tropeptic Eutrustox), was identified as a Metarhizum sp. The density of rhizobial populations established in yeast-mannitol medium in the absence of the fungus was 105 times higher than that established in its presence. However, the fungus did not exert similar antagonistic influence on the rhizobial population incubated with it in the sterilized test soil. Rhizobial growth activity in yeast-mannitol medium was also insensitive to the presence of the fungus when the medium was amended with 1% (wt/vol) kaolinite or montmorillonite. The results suggest that clay minerals may be responsible for protecting rhizobia against toxin-producing fungi in soil. PMID:16346537

  2. Nothing special in the specialist? Draft genome sequence of Cryomyces antarcticus, the most extremophilic fungus from Antarctica.

    Directory of Open Access Journals (Sweden)

    Katja Sterflinger

    Full Text Available The draft genome of the Antarctic endemic fungus Cryomyces antarcticus is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with Neurospora crassa as well as with other microcolonial fungi shows that the fungus has a genome size of 24 Mbp, which is the average in the fungal kingdom. Although sexual reproduction was never observed in this fungus, 34 mating genes are present with protein homologs in the classes Eurotiomycetes, Sordariomycetes and Dothideomycetes. The first analysis of the draft genome did not reveal any significant deviations of this genome from comparative species and mesophilic hyphomycetes.

  3. Nothing Special in the Specialist? Draft Genome Sequence of Cryomyces antarcticus, the Most Extremophilic Fungus from Antarctica

    Science.gov (United States)

    Sterflinger, Katja; Lopandic, Ksenija; Pandey, Ram Vinay; Blasi, Barbara; Kriegner, Albert

    2014-01-01

    The draft genome of the Antarctic endemic fungus Cryomyces antarcticus is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with Neurospora crassa as well as with other microcolonial fungi shows that the fungus has a genome size of 24 Mbp, which is the average in the fungal kingdom. Although sexual reproduction was never observed in this fungus, 34 mating genes are present with protein homologs in the classes Eurotiomycetes, Sordariomycetes and Dothideomycetes. The first analysis of the draft genome did not reveal any significant deviations of this genome from comparative species and mesophilic hyphomycetes. PMID:25296285

  4. Nest enlargement in leaf-cutting ants: relocated brood and fungus trigger the excavation of new chambers.

    Directory of Open Access Journals (Sweden)

    Daniela Römer

    Full Text Available During colony growth, leaf-cutting ants enlarge their nests by excavating tunnels and chambers housing their fungus gardens and brood. Workers are expected to excavate new nest chambers at locations across the soil profile that offer suitable environmental conditions for brood and fungus rearing. It is an open question whether new chambers are excavated in advance, or will emerge around brood or fungus initially relocated to a suitable site in a previously-excavated tunnel. In the laboratory, we investigated the mechanisms underlying the excavation of new nest chambers in the leaf-cutting ant Acromyrmex lundi. Specifically, we asked whether workers relocate brood and fungus to suitable nest locations, and to what extent the relocated items trigger the excavation of a nest chamber and influence its shape. When brood and fungus were exposed to unfavorable environmental conditions, either low temperatures or low humidity, both were relocated, but ants clearly preferred to relocate the brood first. Workers relocated fungus to places containing brood, demonstrating that subsequent fungus relocation spatially follows the brood deposition. In addition, more ants aggregated at sites containing brood. When presented with a choice between two otherwise identical digging sites, but one containing brood, ants' excavation activity was higher at this site, and the shape of the excavated cavity was more rounded and chamber-like. The presence of fungus also led to the excavation of rounder shapes, with higher excavation activity at the site that also contained brood. We argue that during colony growth, workers preferentially relocate brood to suitable locations along a tunnel, and that relocated brood spatially guides fungus relocation and leads to increased digging activity around them. We suggest that nest chambers are not excavated in advance, but emerge through a self-organized process resulting from the aggregation of workers and their density

  5. Novel fungus-Fe3O4 bio-nanocomposites as high performance adsorbents for the removal of radionuclides

    International Nuclear Information System (INIS)

    Highlights: • Fungus was used as a template for the assembly of nano-Fe3O4. • Fungal template directed the nano-Fe3O4 structure from the micro-scale level. • Fungal template enhanced the dispersity and stability of nano-Fe3O4. • Fungus-Fe3O4 exhibited high sorption capacity for Sr(II), Th(IV) and U(VI). • Fungus-Fe3O4 possessed satisfactory regeneration performance and reusability. - Abstract: The bio-nanocomposites of fungus-Fe3O4 were successfully synthesized using a low-cost self-assembly technique. SEM images showed uniform decoration of nano-Fe3O4 particles on fungus surface. The FTIR analysis indicated that nano-Fe3O4 was combined to the fungus surface by chemical bonds. The sorption ability of fungus-Fe3O4 toward Sr(II), Th(IV) and U(VI) was evaluated by batch techniques. Radionuclide sorption on fungus-Fe3O4 was independent of ionic strength, indicating that inner-sphere surface complexion dominated their sorption. XPS analysis indicated that the inner-sphere radionuclide complexes were formed by mainly bonding with oxygen-containing functional groups (i.e., alcohol, acetal and carboxyl) of fungus-Fe3O4. The maximum sorption capacities of fungus-Fe3O4 calculated from Langmuir isotherm model were 100.9, 223.9 and 280.8 mg/g for Sr(II) and U(VI) at pH 5.0, and Th(IV) at pH 3.0, respectively, at 303 K. Fungus-Fe3O4 also exhibited excellent regeneration performance for the preconcentration of radionuclides. The calculated thermodynamic parameters showed that the sorption of radionuclides on fungus-Fe3O4 was a spontaneous and endothermic process. The findings herein highlight the novel synthesis method of fungus-Fe3O4 and its high sorption ability for radionuclides

  6. Anacardic acid induces apoptosis-like cell death in the rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Muzaffar, Suhail; Bose, Chinchu; Banerji, Ashok; Nair, Bipin G; Chattoo, Bharat B

    2016-01-01

    Anacardic acid (6-pentadecylsalicylic acid), extracted from cashew nut shell liquid, is a natural phenolic lipid well known for its strong antibacterial, antioxidant, and anticancer activities. Its effect has been well studied in bacterial and mammalian systems but remains largely unexplored in fungi. The present study identifies antifungal, cytotoxic, and antioxidant activities of anacardic acid in the rice blast fungus Magnaporthe oryzae. It was found that anacardic acid causes inhibition of conidial germination and mycelial growth in this ascomycetous fungus. Phosphatidylserine externalization, chromatin condensation, DNA degradation, and loss of mitochondrial membrane potential suggest that growth inhibition of fungus is mainly caused by apoptosis-like cell death. Broad-spectrum caspase inhibitor Z-VAD-FMK treatment indicated that anacardic acid induces caspase-independent apoptosis in M. oryzae. Expression of a predicted ortholog of apoptosis-inducing factor (AIF) was upregulated during the process of apoptosis, suggesting the possibility of mitochondria dependent apoptosis via activation of apoptosis-inducing factor. Anacardic acid treatment leads to decrease in reactive oxygen species rather than increase in reactive oxygen species (ROS) accumulation normally observed during apoptosis, confirming the antioxidant properties of anacardic acid as suggested by earlier reports. Our study also shows that anacardic acid renders the fungus highly sensitive to DNA damaging agents like ethyl methanesulfonate (EMS). Treatment of rice leaves with anacardic acid prevents M. oryzae from infecting the plant without affecting the leaf, suggesting that anacardic acid can be an effective antifungal agent. PMID:26381667

  7. Caspase-1 and 3 Inhibiting Drimane Sesquiterpenoids from the Extremophilic Fungus, Penicillium solitum

    OpenAIRE

    Stierle, Donald B.; Stierle, Andrea A.; Girtsman, Teri; McIntyre, Kyle; Nichols, Jesse

    2012-01-01

    Two new drimane sesquiterpene lactones and one new tricarboxylic acid derivative were isolated from the Berkeley Pit extremophilic fungus Penicillium solitum. The structures of these compounds were deduced by spectroscopic analysis. Berkedrimanes A and B inhibited the signal transduction enzymes caspase-1 and caspase-3 and mitigated the production of interleukin 1-β in the induced THP-1 (promonocytic leukemia cell line) assay.

  8. A highly diverse spectrum of naphthoquinone derivatives produced by the endophytic fungus Biatriospora sp CCF 4378

    Czech Academy of Sciences Publication Activity Database

    Stodůlková, Eva; Man, Petr; Kuzma, Marek; Černý, J.; Císařová, I.; Kubátová, A.; Chudíčková, Milada; Kolařík, Miroslav; Flieger, Miroslav

    2015-01-01

    Roč. 60, č. 3 (2015), s. 259-267. ISSN 0015-5632 R&D Projects: GA MŠk(CZ) LD13039; GA ČR GA13-16565S Institutional support: RVO:61388971 Keywords : NECTRIA-HAEMATOCOCCA * ASCOMYCETOUS FUNGUS * BIOLOGICAL-ACTIVITY Subject RIV: EE - Microbiology, Virology Impact factor: 1.000, year: 2014

  9. Production of microsclerotia of the entomopathogenic fungus Metarhizium anisopliae in liquid culture

    Science.gov (United States)

    The goal of this study was the development of a liquid culture method for producing stable, infective propagules of the entomopathogenic fungus Metarhizium anisopliae for control of soil-dwelling insect pests. Three strains of M. anisopliae, F52, TM109, and MA1200, were evaluated using aerated, liq...

  10. Short read sequencing for Genomic Analysis of the brown rot fungus Fibroporia radiculosa

    Science.gov (United States)

    The practical capability of short read sequencing for whole genome gene prediction was investigated for Fibroporia radiculosa, a copper-tolerant basidiomycete fungus that causes brown rot decay of wood. Illumina GAIIX reads from a single run of a paired-end library (75 nt read length, 300 bp insert...

  11. A New Eudesmane Sesquiterpene from Nigrospora oryzae, an Endophytic Fungus of Aquilaria sinensis

    Directory of Open Access Journals (Sweden)

    Dongli Li

    2014-07-01

    Full Text Available A new eudesmane-type sesquiterpene, 11 -hydroxy capitulatin B (1 , along with a known related sesquiterpene, capitulatin B (2, was isolated from the endophytic fungus Nigrospora oryzae A8 from Aquilaria sinensis, the only plant resource for agarwood production in China. This research demonstrates that the endophytic fungi from A. sinensis might play a role in the formation of agarwood.

  12. Clove oil and fungus compounds: Can nematode suppression be achieved without phytotoxicity?

    Science.gov (United States)

    Natural products from a plant (Syzygium aromaticum) and a fungus (Aspergillus sp.) were examined for the presence of compounds with potential for application as novel nematicides. The plant-derived material, clove oil, was tested in the greenhouse against the nematode Meloidogyne incognita on cucum...

  13. Caste-specific symbiont policing by workers of Acromyrmex fungus-growing ants

    NARCIS (Netherlands)

    Ivens, Aniek B. F.; Nash, David R.; Poulsen, Michael; Boomsma, Jacobus J.

    2009-01-01

    The interaction between leaf-cutting ants and their fungus garden mutualists is ideal for studying the evolutionary stability of interspecific cooperation. Although the mutualism has a long history of diffuse coevolution, there is ample potential for conflicts between the partners over the mixing an

  14. Ethanol Production from Various Sugars and Cellulosic Biomass by White Rot Fungus Lenzites betulinus.

    Science.gov (United States)

    Im, Kyung Hoan; Nguyen, Trung Kien; Choi, Jaehyuk; Lee, Tae Soo

    2016-03-01

    Lenzites betulinus, known as gilled polypore belongs to Basidiomycota was isolated from fruiting body on broadleaf dead trees. It was found that the mycelia of white rot fungus Lenzites betulinus IUM 5468 produced ethanol from various sugars, including glucose, mannose, galactose, and cellobiose with a yield of 0.38, 0.26, 0.07, and 0.26 g of ethanol per gram of sugar consumed, respectively. This fungus relatively exhibited a good ethanol production from xylose at 0.26 g of ethanol per gram of sugar consumed. However, the ethanol conversion rate of arabinose was relatively low (at 0.07 g of ethanol per gram sugar). L. betulinus was capable of producing ethanol directly from rice straw and corn stalks at 0.22 g and 0.16 g of ethanol per gram of substrates, respectively, when this fungus was cultured in a basal medium containing 20 g/L rice straw or corn stalks. These results indicate that L. betulinus can produce ethanol efficiently from glucose, mannose, and cellobiose and produce ethanol very poorly from galactose and arabinose. Therefore, it is suggested that this fungus can ferment ethanol from various sugars and hydrolyze cellulosic materials to sugars and convert them to ethanol simultaneously. PMID:27103854

  15. Selection of reference genes for expression analysis in the entomophthoralean fungus Pandora neoaphidis

    DEFF Research Database (Denmark)

    Eilenberg, Jørgen; Jensen, Annette Bruun; Chen, Chun

    2016-01-01

    The selection of suitable reference genes is crucial for accurate quantification of gene expres-sion and can add to our understanding of host–pathogen interactions. To identify suitablereference genes in Pandora neoaphidis, an obligate aphid pathogenic fungus, the expressionof three traditional...

  16. Regulation of the Cyanide-Resistant Alternative Respiratory Pathway in the Fungus Acremonium chrysogenum

    OpenAIRE

    Sándor, Erzsébet; Fekete, Erzsébet; Karaffa, Levente

    2003-01-01

    This review summarises the current knowledge on the biochemical and physiological events that directly or indirectly alter the engagement of the cyanide-resistant alternative respiratory pathway in the cephalosporin C producer filamentous fungus Acremonium chrysogenum. Particular emphasis is placed on the role this activity plays in the overproduction of antibiotic, and also on the critical fermentation technology background that supports its operation.

  17. DEVELOPMENT OF SIMPLE SEQUENCE REPEAT MARKERS FOR THE PLANT PATHOGENIC RUST FUNGUS, PUCCINIA GRAMINIS

    Science.gov (United States)

    Twenty-four dinucleotide simple sequence repeat markers were developed for the phytopathogenic fungus, Puccinia graminis. The identified loci were polymorphic, with allelic diversity ranging from 2 to 11 alleles. Levels of heterozygosity ranged from 0.000 to 0.960 and 0.113 to 0.846 for observed and...

  18. Treatment of a textile effluent from dyeing with cochineal extracts using Trametes versicolor fungus.

    Science.gov (United States)

    Arroyo-Figueroa, Gabriela; Ruiz-Aguilar, Graciela M L; López-Martínez, Leticia; González-Sánchez, Guillermo; Cuevas-Rodríguez, Germán; Rodríguez-Vázquez, Refugio

    2011-01-01

    Trametes versicolor (Tv) fungus can degrade synthetic dyes that contain azo groups, anthraquinone, triphenylmethane polymers, and heterocyclic groups. However, no references have been found related to the degradation of natural dyes, such as the carminic acid that is contained in the cochineal extract. Experiments to determine the decolorization of the effluent used in the cotton dyeing process with cochineal extract by means of Tv fungus were done. Treatments to determine decolorization in the presence or absence of Kirk's medium, glucose, and fungus, with an addition of 50% (v v-1) of nonsterilized effluent were performed. Physicochemical characterization was performed at the start and end of the treatment. Degradation kinetics were determined. A direct relationship was found between the dry weight of fungi, pH, and the decolorization system, with higher decolorization at lower pH levels (pH ~4.3). High decolorization (81% ± 0.09; 88% ± 0.17; and 99% ± 0.04) for three of the eight treatments (Kirk's medium without glucose, Kirk's medium with glucose, and without medium with glucose, respectively) was found. Toxicity tests determined an increase in the initial effluent toxicity (7.33 TU) compared with the final treatment (47.73 TU) in a period of 11 days. For this system, a degradation sequence of the carminic acid structure present in the effluent by the Tv fungus is suggested, in which it is seen that metabolites still containing aromatic structures are generated. PMID:21552764

  19. Infection of adult Aedes aegypti and Ae. albopictus mosquitoes with the entomopathogenic fungus Metarhizium anisopliae

    NARCIS (Netherlands)

    Scholte, E.J.; Takken, W.; Knols, B.G.J.

    2007-01-01

    This study describes a laboratory investigation on the use of the insect-pathogenic fungus Metarhizium anisopliae against adult Aedes aegypti and Ae. albopictus mosquitoes. At a dosage of 1.6 × 1010 conidia/m2, applied on material that served as a mosquito resting site, an average of 87.1 ± 2.65% of

  20. Monodictyquinone A: a new antimicrobial anthraquinone from a sea urchin-derived fungus Monodictys sp.

    Science.gov (United States)

    El-Beih, Ahmed Atef; Kawabata, Tetsuro; Koimaru, Keiichiro; Ohta, Tomihisa; Tsukamoto, Sachiko

    2007-07-01

    A new antimicrobial anthraquinone, 1,8-dihydroxy-2-methoxy-6-methylanthraquinone, monodictyquinone A (1), was isolated from a culture of a marine-derived fungus of the genus Monodictys which was isolated from the sea urchin, Anthocidaris crassispina, along with three known compounds, pachybasin (2), chrysophanol (3), and emodin (4). PMID:17603212