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Mark R. H. Hurst - One of the best experts on this subject based on the ideXlab platform.
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Assessment of toxicity and persistence of Yersinia Entomophaga and its Yen-Tc associated toxin.
Pest management science, 2020Co-Authors: Mark R. H. Hurst, Sandra M. Jones, Sandra Young, S. Muetzel, Joanne Calder, Chikako Van KotenAbstract:BACKGROUND The insect-pathogenic bacterium Yersinia Entomophaga MH96 is currently under development as a microbial pesticide active against various pasture and crop pests such as the diamondback moth Plutella xylostella and the cotton bollworm Helicoverpa armigeria. To enable nonrestricted field trials of Y. Entomophaga MH96, information on the persistence and nontarget effects of the bacterium and its Yen-Tc proteinaceous toxin are required. RESULTS The Y. Entomophaga Yen-Tc associated toxin was found to have limited persistence on foliage and is inactivated by UV light. The Yen-Tc was rapidly degraded in ovine or bovine rumen fluid or the intestinal fluid of H. armigera. In H. armigera an intestinal protein of >50 kDa was found to cleave the Yen-Tc bond. Assessment of Y. Entomophaga persistence on foliage and in soil found that after 42 days the bacterium could not be detected in soil at 20% soil moisture content but persisted for 72 days at 30-40% soil moisture. Nontarget effects of Y. Entomophaga towards earthworms found that the bacterium afforded no adverse effects on worm growth or behavior. A summary of historic Yen-Tc and Y. Entomophaga persistence and toxicity data is presented. CONCLUSION The bacterium Y. Entomophaga and its Yen-Tc associated toxin have limited persistence in the environment, with the Yen-Tc being susceptible to UV inactivation and proteolytic degradation, and the bacterium persisting longer in soil of a high moisture content. © 2020 Society of Chemical Industry.
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Development of a Yersinia Entomophaga bait for control of larvae of the porina moth (Wiseana spp.), a pest of New Zealand improved grassland systems
Pest management science, 2019Co-Authors: Mark R. H. Hurst, Amy K. Beattie, J. Swaminathan, David A. Wright, Scott Hardwick, Colin M. Ferguson, Nicola K. Richards, Lincoln Harper, Ray A. Moss, Vanessa M. CaveAbstract:BACKGROUND Porina is the common name for moths and larvae of the genus Wiseana (Lepidoptera: Hepialidae), some of which are significant pasture pests in New Zealand. Because of environmental concerns and the non-target effects of insecticide control measures, biological alternatives for the control of insect pests such as porina are required. RESULTS Using a food preference assay and time-lapse photography, a range of low-cost food ingredients were assessed for their palatability to porina larvae. Lead candidates were combined into extruded bait variants, allowing assessment of their palatability to porina larvae. A composite bait consisting of palatable ingredients was developed, into which the porina-active entomopathogen Yersinia Entomophaga was incorporated. A 7 day minimum median lethal dose of approximately 6.0 × ±1 × 106 Y. Entomophaga cells per 0.02 g of bait was defined. Field trials showed that the mean change in larval density over time differed between treatments, with Y. Entomophaga bait applied at 87 kg ha-1 resulting in a mean 65% reduction in larval density relative to the control plots, and diflubenzuron treatment resulting in a mean 77% reduction relative to the control plots. The mean dry matter yields over the course of the trial were highest for diflubenzuron (5029 kg ha-1 ), followed by the Y. Entomophaga (4783 kg ha-1 ) and control (4673 kg ha-1 ) treatments. CONCLUSIONS The bacterium Y. Entomophaga applied as a composite bait offers an environmentally sustainable approach for porina pest control. © 2019 Society of Chemical Industry.
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assessment of yersinia Entomophaga as a control agent of the diamondback moth plutella xylostella
Journal of Invertebrate Pathology, 2019Co-Authors: Mark R. H. Hurst, Chikako Van Koten, Amy K. Beattie, Sandra A. Jones, Anthony M Shelton, Hilda L Collins, Michael BrownbridgeAbstract:Abstract The application of the biocontrol bacterium Yersinia Entomophaga as a foliar spray was assessed for its efficacy against larvae of the diamondback moth, Plutella xylostella. The bacterium was applied as either a broth suspension, or as a biopolymer-based gel foliar spray and compared with commercial insecticides Dipel (Bacillus thuringiensis) and Spinosad. The performance of Y. Entomophaga was comparable with that of Dipel. The gel-based formulation extended leaf persistence over that of the basic broth culture spray, while also providing higher initial foliar deposition rates. The bacterium was found to multiply within the P. xylostella larvae to 5.8 × 105 cells per larva, while the median lethal dose (LD50) was determined to be 2.69 × 103 cells per larva. Importantly, B. thuringiensis Cry1A-resistant, Cry1C-resistant, indoxacarb/pyrethroid-resistant, and Spinosad-resistant P. xylostella larvae were susceptible to Y. Entomophaga.
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Structure and gene cluster of a tyvelose-containing O-polysaccharide of an entomopathogenic bacterium Yersinia Entomophaga MH96T related to Yersinia pseudotuberculosis.
Carbohydrate Research, 2017Co-Authors: Olga V. Sizova, Mark R. H. Hurst, Anna N. Kondakova, A. S. Shashkov, Y. A. Knirel, Rima Z. Shaikhutdinova, Sergey A. Ivanov, M. E. Platonov, Svetlana V. DentovskayaAbstract:Abstract An O-polysaccharide was isolated from the lipopolysaccharide of an entomopathogenic bacterium Yersinia Entomophaga MH96T by mild acid hydrolysis and studied by 2D NMR spectroscopy. The following structure of the branched tetrasaccharide repeating unit of the polysaccharide was established: Download : Download high-res image (52KB) Download : Download full-size image where Tyv indicates 3,6-dideoxy- d -arabino-hexose (tyvelose). The structure established is consistent with the gene content of the O-antigen gene cluster. The O-polysaccharide structure and gene cluster of Y. Entomophaga are related to those of some Y. pseudotuberculosis serotypes.
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The Draft Genome Sequence of the Yersinia Entomophaga Entomopathogenic Type Strain MH96T.
Toxins, 2016Co-Authors: Mark R. H. Hurst, Joanne Calder, Amy K. Beattie, Lincoln Harper, Eric Altermann, Roger Moraga, Aurelie LaugraudAbstract:Here we report the draft genome of Yersinia Entomophaga type strain MH96T. The genome shows 93.8% nucleotide sequence identity to that of Yersinia nurmii type strain APN3a-cT, and comprises a single chromosome of approximately 4,275,531 bp. In silico analysis identified that, in addition to the previously documented Y. Entomophaga Yen-TC gene cluster, the genome encodes a diverse array of toxins, including two type III secretion systems, and five rhs-associated gene clusters. As well as these multicomponent systems, several orthologs of known insect toxins, such as VIP2 toxin and the binary toxin PirAB, and distant orthologs of some mammalian toxins, including repeats-in-toxin, a cytolethal distending toxin, hemolysin-like genes and an adenylate cyclase were identified. The genome also contains a large number of hypothetical proteins and orthologs of known effector proteins, such as LopT, as well as genes encoding a wide range of proteolytic determinants, including metalloproteases and pathogen fitness determinants, such as genes involved in iron metabolism. The bioinformatic data derived from the current in silico analysis, along with previous information on the pathobiology of Y. Entomophaga against its insect hosts, suggests that a number of these virulence systems are required for survival in the hemocoel and incapacitation of the insect host.
Chikako Van Koten - One of the best experts on this subject based on the ideXlab platform.
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Assessment of toxicity and persistence of Yersinia Entomophaga and its Yen-Tc associated toxin.
Pest management science, 2020Co-Authors: Mark R. H. Hurst, Sandra M. Jones, Sandra Young, S. Muetzel, Joanne Calder, Chikako Van KotenAbstract:BACKGROUND The insect-pathogenic bacterium Yersinia Entomophaga MH96 is currently under development as a microbial pesticide active against various pasture and crop pests such as the diamondback moth Plutella xylostella and the cotton bollworm Helicoverpa armigeria. To enable nonrestricted field trials of Y. Entomophaga MH96, information on the persistence and nontarget effects of the bacterium and its Yen-Tc proteinaceous toxin are required. RESULTS The Y. Entomophaga Yen-Tc associated toxin was found to have limited persistence on foliage and is inactivated by UV light. The Yen-Tc was rapidly degraded in ovine or bovine rumen fluid or the intestinal fluid of H. armigera. In H. armigera an intestinal protein of >50 kDa was found to cleave the Yen-Tc bond. Assessment of Y. Entomophaga persistence on foliage and in soil found that after 42 days the bacterium could not be detected in soil at 20% soil moisture content but persisted for 72 days at 30-40% soil moisture. Nontarget effects of Y. Entomophaga towards earthworms found that the bacterium afforded no adverse effects on worm growth or behavior. A summary of historic Yen-Tc and Y. Entomophaga persistence and toxicity data is presented. CONCLUSION The bacterium Y. Entomophaga and its Yen-Tc associated toxin have limited persistence in the environment, with the Yen-Tc being susceptible to UV inactivation and proteolytic degradation, and the bacterium persisting longer in soil of a high moisture content. © 2020 Society of Chemical Industry.
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assessment of yersinia Entomophaga as a control agent of the diamondback moth plutella xylostella
Journal of Invertebrate Pathology, 2019Co-Authors: Mark R. H. Hurst, Chikako Van Koten, Amy K. Beattie, Sandra A. Jones, Anthony M Shelton, Hilda L Collins, Michael BrownbridgeAbstract:Abstract The application of the biocontrol bacterium Yersinia Entomophaga as a foliar spray was assessed for its efficacy against larvae of the diamondback moth, Plutella xylostella. The bacterium was applied as either a broth suspension, or as a biopolymer-based gel foliar spray and compared with commercial insecticides Dipel (Bacillus thuringiensis) and Spinosad. The performance of Y. Entomophaga was comparable with that of Dipel. The gel-based formulation extended leaf persistence over that of the basic broth culture spray, while also providing higher initial foliar deposition rates. The bacterium was found to multiply within the P. xylostella larvae to 5.8 × 105 cells per larva, while the median lethal dose (LD50) was determined to be 2.69 × 103 cells per larva. Importantly, B. thuringiensis Cry1A-resistant, Cry1C-resistant, indoxacarb/pyrethroid-resistant, and Spinosad-resistant P. xylostella larvae were susceptible to Y. Entomophaga.
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Temperature-Dependent Galleria mellonella Mortality as a Result of Yersinia Entomophaga Infection.
Applied and environmental microbiology, 2015Co-Authors: Mark R. H. Hurst, Joanne Calder, Amy K. Beattie, Sandra A. Jones, Pei-chun Hsu, Chikako Van KotenAbstract:ABSTRACT The bacterium Yersinia Entomophaga is pathogenic to a range of insect species, with death typically occurring within 2 to 5 days of ingestion. Per os challenge of larvae of the greater wax moth (Galleria mellonella) confirmed that Y. Entomophaga was virulent when fed to larvae held at 25°C but was avirulent when fed to larvae maintained at 37°C. At 25°C, a dose of ∼4 × 107 CFU per larva of a Y. Entomophaga toxin complex (Yen-TC) deletion derivative, the Y. Entomophaga ΔTC variant, resulted in 27% mortality. This low level of activity was restored to near-wild-type levels by augmentation of the diet with a sublethal dose of purified Yen-TC. Intrahemocoelic injection of ∼3 Y. Entomophaga or Y. Entomophaga ΔTC cells per larva gave a 4-day median lethal dose, with similar levels of mortality observed at both 25 and 37°C. Following intrahemocoelic injection of a Yen-TC YenA1 green fluorescent protein fusion strain into larvae maintained at 25°C, the bacteria did not fluoresce until the population density reached 2 × 107 CFU ml−1 of hemolymph. The observed cells also took an irregular form. When the larvae were maintained at 37°C, the cells were small and the observed fluorescence was sporadic and weak, being more consistent at a population density of ∼3 × 109 CFU ml−1 of hemolymph. These findings provide further understanding of the pathobiology of Y. Entomophaga in insects, showing that the bacterium gains direct access to the hemocoelic cavity, from where it rapidly multiplies to cause disease.
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Pathology of Yersinia Entomophaga MH96 towards Costelytra zealandica (Coleoptera; Scarabaeidae) larvae.
Journal of invertebrate pathology, 2013Co-Authors: Mark R. H. Hurst, Chikako Van Koten, Trevor A. JacksonAbstract:Abstract The bacterium Yersinia Entomophaga was isolated from larvae of the New Zealand grass grub, Costelytra zealandica (Coleoptera: Scarabaeidae), found in soil. Following ingestion of a lethal dose of bacteria, larvae of C. zealandica reduced feeding activity and movement. After approximately 4 h infected larvae convulsed and regurgitated dark digestive fluid and expelled frass pellets leaving the midgut empty and the larva amber in appearance. In the initial stages of infection, ingested bacteria were mostly contained within the peritrophic membrane and expelled with the gut fluid or transferred into the hind gut. While few Y. Entomophaga were associated with the midgut epithelial cells, by 24 h cells were swelling and bursting with vesicles being expelled into the midgut lumen. By 48 h, bacteria had entered the haemocoel and the midgut cells had further deteriorated. After 72 h, the cellular remnants were totally detached from the basal membrane the infected insects were filled with bacteria and moribund or dead with septicaemia. Mortality was directly proportional to dose and time after infection. By applying a range of doses, the LD50 was determined as 2.9 × 104 Y. Entomophaga per C. zealandica larva, with an LT50 of 2.94 days for doses of >1 × 105 per larva. Ingestion of low doses of bacteria did not inhibit feeding activity but led more slowly to death. By time of death, Y. Entomophaga had multiplied, approximately 500 fold, in the cadavers of the infected larvae.
Sandra A. Jones - One of the best experts on this subject based on the ideXlab platform.
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assessment of yersinia Entomophaga as a control agent of the diamondback moth plutella xylostella
Journal of Invertebrate Pathology, 2019Co-Authors: Mark R. H. Hurst, Chikako Van Koten, Amy K. Beattie, Sandra A. Jones, Anthony M Shelton, Hilda L Collins, Michael BrownbridgeAbstract:Abstract The application of the biocontrol bacterium Yersinia Entomophaga as a foliar spray was assessed for its efficacy against larvae of the diamondback moth, Plutella xylostella. The bacterium was applied as either a broth suspension, or as a biopolymer-based gel foliar spray and compared with commercial insecticides Dipel (Bacillus thuringiensis) and Spinosad. The performance of Y. Entomophaga was comparable with that of Dipel. The gel-based formulation extended leaf persistence over that of the basic broth culture spray, while also providing higher initial foliar deposition rates. The bacterium was found to multiply within the P. xylostella larvae to 5.8 × 105 cells per larva, while the median lethal dose (LD50) was determined to be 2.69 × 103 cells per larva. Importantly, B. thuringiensis Cry1A-resistant, Cry1C-resistant, indoxacarb/pyrethroid-resistant, and Spinosad-resistant P. xylostella larvae were susceptible to Y. Entomophaga.
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Cryo-EM structures of the pore-forming A subunit from the Yersinia Entomophaga ABC toxin
Nature Publishing Group, 2019Co-Authors: Sarah J Piper, Sandra A. Jones, Lou Brillault, Rosalba Rothnagel, Tristan I Croll, Joseph K Box, Irene Chassagnon, Sebastian Scherer, Kenneth N Goldie, Femke SchepersAbstract:YenTcA is the pore-forming and membrane binding subunit of the ABC toxin YenTc, which is produced by the insect pathogen Yersinia Entomophaga. Here authors present cryo-EM structures of YenTcA purified from the native source which implicate associated endochitinases in host cell recognition
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Temperature-Dependent Galleria mellonella Mortality as a Result of Yersinia Entomophaga Infection.
Applied and environmental microbiology, 2015Co-Authors: Mark R. H. Hurst, Joanne Calder, Amy K. Beattie, Sandra A. Jones, Pei-chun Hsu, Chikako Van KotenAbstract:ABSTRACT The bacterium Yersinia Entomophaga is pathogenic to a range of insect species, with death typically occurring within 2 to 5 days of ingestion. Per os challenge of larvae of the greater wax moth (Galleria mellonella) confirmed that Y. Entomophaga was virulent when fed to larvae held at 25°C but was avirulent when fed to larvae maintained at 37°C. At 25°C, a dose of ∼4 × 107 CFU per larva of a Y. Entomophaga toxin complex (Yen-TC) deletion derivative, the Y. Entomophaga ΔTC variant, resulted in 27% mortality. This low level of activity was restored to near-wild-type levels by augmentation of the diet with a sublethal dose of purified Yen-TC. Intrahemocoelic injection of ∼3 Y. Entomophaga or Y. Entomophaga ΔTC cells per larva gave a 4-day median lethal dose, with similar levels of mortality observed at both 25 and 37°C. Following intrahemocoelic injection of a Yen-TC YenA1 green fluorescent protein fusion strain into larvae maintained at 25°C, the bacteria did not fluoresce until the population density reached 2 × 107 CFU ml−1 of hemolymph. The observed cells also took an irregular form. When the larvae were maintained at 37°C, the cells were small and the observed fluorescence was sporadic and weak, being more consistent at a population density of ∼3 × 109 CFU ml−1 of hemolymph. These findings provide further understanding of the pathobiology of Y. Entomophaga in insects, showing that the bacterium gains direct access to the hemocoelic cavity, from where it rapidly multiplies to cause disease.
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Assessing the potential of Yersinia Entomophaga to control plantain moth in a laboratory assay
New Zealand Plant Protection, 2015Co-Authors: Sandra A. Jones, Colin M. Ferguson, B.a. Philip, C. Van Koten, Mark R. H. HurstAbstract:The recent increased use of the high-quality drought-tolerant forage plant plantain (Plantago lanceolata) (Plantaginaceae) has been associated with outbreaks of native geometrid caterpillars, such as Scopula rubraria. The outbreaks most often occur under warm climatic conditions and within plantain monocrops. Pest populations can reach 11,500 larvae/m 2 . Stands can be severely damaged with 90% of plants destroyed and stand life expectancy reduced by 2-3 years. This study assessed the efficacy of the insecticidal bacterium Yersinia Entomophaga against S. rubraria under laboratory conditions using a leaf dip bioassay. A LD50 of 2.26 ± 0.33×10 5 cells per larva was determined with an LT50 defined as 3.1 days when treated with 4.8×10 6 cells per larva. These data combined with the life history of S. rubraria and the pathobiology of Y. Entomophaga suggest the bacterium could be developed as a biopesticide for use against S. rubraria.
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Structural Analysis of Chi1 Chitinase from Yen-Tc: The Multisubunit Insecticidal ABC Toxin Complex of Yersinia Entomophaga
Journal of molecular biology, 2011Co-Authors: J.n. Busby, Mark R. H. Hurst, Sandra A. Jones, Michael J. Landsberg, Robert M. Simpson, Ben Hankamer, J. Shaun LottAbstract:Yersinia Entomophaga MH96 is a native New Zealand soil bacterium that secretes a large ABC-type protein toxin complex, Yen-Tc, similar to those produced by nematode-associated bacteria such as Photorhabdus luminescens. Y. Entomophaga displays an exceptionally virulent pathogenic phenotype in sensitive insect species, causing death within 72 h of infection. Because of this phenotype, there is intrinsic interest in the mechanism of action of Yen-Tc, and it also has the potential to function as a novel class of biopesticide. We have identified genes that encode chitinases as part of the toxin complex loci in Y. Entomophaga MH96, P. luminescens, Photorhabdus asymbiotica and Xenorhabdus nematophila. Furthermore, we have shown that the secreted toxin complex from Y. Entomophaga MH96 includes two chitinases as an integral part of the complex, a feature not described previously in other ABC toxins and possibly related to the severe disease caused by this bacterium. We present here the structure of the Y. Entomophaga MH96 Chi1 chitinase, determined by X-ray crystallography to 1.74 A resolution, and show that a ring of five symmetrically arranged lobes on the surface of the Yen-Tc toxin complex structure, as determined by single-particle electron microscopy, provides a good fit to the Chi1 monomer. We also confirm that the isolated chitinases display endochitinase activity, as does the complete toxin complex.
Ann E. Hajek - One of the best experts on this subject based on the ideXlab platform.
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Appendix C. Microscopic identification of LdNPV and Entomophaga maimaiga in larval cadavers.
2016Co-Authors: Andrew M. Liebhold, Ruth C. Plymale, Joseph S. Elkinton, Ann E. HajekAbstract:Microscopic identification of LdNPV and Entomophaga maimaiga in larval cadavers
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first record of Entomophaga maimaiga entomophthorales entomophthoraceae in georgia
Biocontrol Science and Technology, 2011Co-Authors: Manana Kereselidze, Daniela Pilarska, Ann E. Hajek, Annette Bruun Jensen, Andreas LindeAbstract:Abstract In 2005, high levels of mortality occurred in an outbreak of the gypsy moth population in Georgia. Resting spores typical of entomophthoralean fungi were found within larval cadavers and molecular analyses confirmed that the pathogen was Entomophaga maimaiga. This is the first record of this entomopathogen in Georgia and in this part of Europe.
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Assessing the climatic potential for epizootics of the gypsy moth fungal pathogen Entomophaga maimaiga in the North Central United States
Canadian Journal of Forest Research, 2009Co-Authors: Nathan W. Siegert, Ann E. Hajek, Deborah G. Mccullough, Robert C. Venetter.c. Venette, Jeffrey A. AndresenAbstract:The fungal pathogen Entomophaga maimaiga Humber, Shimazu et Soper has become an important biocontrol for gypsy moth (Lymantria dispar (L.)) in the northeastern United States and is commonly introdu...
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SPATIAL POPULATION DYNAMICS AND HETEROGENEITY OF AN INSECT/PATHOGEN INTERACTION
2009Co-Authors: Ruth C. Plymale, Andrew M. Liebhold, Ann E. HajekAbstract:Dispersal and habitat heterogeneity are known to play important roles in the dynamics of interactions between natural enemies and their hosts. The fungal pathogen Entomophaga maimaiga was first found in North America in 1989 and subsequently spread across the gypsy moth distribution, causing epizootics in gypsy moth populations.
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PCR-RFLP is used to investigate relations among species in the entomopathogenic genera Eryniopsis and Entomophaga
Mycologia, 2003Co-Authors: Ann E. Hajek, Annette Bruun Jensen, Lene Thomsen, Kathie T. Hodge, Jørgen EilenbergAbstract:The shape and nucleation of primary conidia are important characters in the classification of the Entomophthoraceae (Zygomycetes). The five species in the genus Eryniopsis vary in the shapes of primary conidia, although within most genera in the order Entomophthorales species have the same shapes of primary conidia. Using PCR-RFLP, we investigated two species in Eryniopsis, Ery. caroliniana with oblong-ovoid primary conidia and Ery. ptychopterae with pear-shaped primary conidia, with five species of Entomophaga, all having pear-shaped conidia. Molecular results merged with morphological data indicate that Ery. ptychopterae belongs in the genus Entomophaga while Ery. caroliniana clearly differs from Entomophaga. Ery. ptychopterae and Ery. transitans are transferred to the genus Entomophaga. Our results support the idea that morphology of primary conidia is of major importance in defining entomophthoralean genera. These results also show that such studies can be conducted with species that have not been isolated, if fungal-filled cadavers can be obtained.
Joanne Calder - One of the best experts on this subject based on the ideXlab platform.
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Assessment of toxicity and persistence of Yersinia Entomophaga and its Yen-Tc associated toxin.
Pest management science, 2020Co-Authors: Mark R. H. Hurst, Sandra M. Jones, Sandra Young, S. Muetzel, Joanne Calder, Chikako Van KotenAbstract:BACKGROUND The insect-pathogenic bacterium Yersinia Entomophaga MH96 is currently under development as a microbial pesticide active against various pasture and crop pests such as the diamondback moth Plutella xylostella and the cotton bollworm Helicoverpa armigeria. To enable nonrestricted field trials of Y. Entomophaga MH96, information on the persistence and nontarget effects of the bacterium and its Yen-Tc proteinaceous toxin are required. RESULTS The Y. Entomophaga Yen-Tc associated toxin was found to have limited persistence on foliage and is inactivated by UV light. The Yen-Tc was rapidly degraded in ovine or bovine rumen fluid or the intestinal fluid of H. armigera. In H. armigera an intestinal protein of >50 kDa was found to cleave the Yen-Tc bond. Assessment of Y. Entomophaga persistence on foliage and in soil found that after 42 days the bacterium could not be detected in soil at 20% soil moisture content but persisted for 72 days at 30-40% soil moisture. Nontarget effects of Y. Entomophaga towards earthworms found that the bacterium afforded no adverse effects on worm growth or behavior. A summary of historic Yen-Tc and Y. Entomophaga persistence and toxicity data is presented. CONCLUSION The bacterium Y. Entomophaga and its Yen-Tc associated toxin have limited persistence in the environment, with the Yen-Tc being susceptible to UV inactivation and proteolytic degradation, and the bacterium persisting longer in soil of a high moisture content. © 2020 Society of Chemical Industry.
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The Draft Genome Sequence of the Yersinia Entomophaga Entomopathogenic Type Strain MH96T.
Toxins, 2016Co-Authors: Mark R. H. Hurst, Joanne Calder, Amy K. Beattie, Lincoln Harper, Eric Altermann, Roger Moraga, Aurelie LaugraudAbstract:Here we report the draft genome of Yersinia Entomophaga type strain MH96T. The genome shows 93.8% nucleotide sequence identity to that of Yersinia nurmii type strain APN3a-cT, and comprises a single chromosome of approximately 4,275,531 bp. In silico analysis identified that, in addition to the previously documented Y. Entomophaga Yen-TC gene cluster, the genome encodes a diverse array of toxins, including two type III secretion systems, and five rhs-associated gene clusters. As well as these multicomponent systems, several orthologs of known insect toxins, such as VIP2 toxin and the binary toxin PirAB, and distant orthologs of some mammalian toxins, including repeats-in-toxin, a cytolethal distending toxin, hemolysin-like genes and an adenylate cyclase were identified. The genome also contains a large number of hypothetical proteins and orthologs of known effector proteins, such as LopT, as well as genes encoding a wide range of proteolytic determinants, including metalloproteases and pathogen fitness determinants, such as genes involved in iron metabolism. The bioinformatic data derived from the current in silico analysis, along with previous information on the pathobiology of Y. Entomophaga against its insect hosts, suggests that a number of these virulence systems are required for survival in the hemocoel and incapacitation of the insect host.
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Temperature-Dependent Galleria mellonella Mortality as a Result of Yersinia Entomophaga Infection.
Applied and environmental microbiology, 2015Co-Authors: Mark R. H. Hurst, Joanne Calder, Amy K. Beattie, Sandra A. Jones, Pei-chun Hsu, Chikako Van KotenAbstract:ABSTRACT The bacterium Yersinia Entomophaga is pathogenic to a range of insect species, with death typically occurring within 2 to 5 days of ingestion. Per os challenge of larvae of the greater wax moth (Galleria mellonella) confirmed that Y. Entomophaga was virulent when fed to larvae held at 25°C but was avirulent when fed to larvae maintained at 37°C. At 25°C, a dose of ∼4 × 107 CFU per larva of a Y. Entomophaga toxin complex (Yen-TC) deletion derivative, the Y. Entomophaga ΔTC variant, resulted in 27% mortality. This low level of activity was restored to near-wild-type levels by augmentation of the diet with a sublethal dose of purified Yen-TC. Intrahemocoelic injection of ∼3 Y. Entomophaga or Y. Entomophaga ΔTC cells per larva gave a 4-day median lethal dose, with similar levels of mortality observed at both 25 and 37°C. Following intrahemocoelic injection of a Yen-TC YenA1 green fluorescent protein fusion strain into larvae maintained at 25°C, the bacteria did not fluoresce until the population density reached 2 × 107 CFU ml−1 of hemolymph. The observed cells also took an irregular form. When the larvae were maintained at 37°C, the cells were small and the observed fluorescence was sporadic and weak, being more consistent at a population density of ∼3 × 109 CFU ml−1 of hemolymph. These findings provide further understanding of the pathobiology of Y. Entomophaga in insects, showing that the bacterium gains direct access to the hemocoelic cavity, from where it rapidly multiplies to cause disease.