Read by QxMD icon Read

Metarhizium robertsii

Barbara Różalska, Beata Sadowska, Aleksandra Budzyńska, Przemysław Bernat, Sylwia Różalska
Due to low efficacy of classic antimicrobial drugs, finding new active preparations attracts much attention. In this study an innovative, cost-effective and environmentally friendly method was applied to produce silver nanoparticles (AgNPs) using filamentous fungi Metarhizium robertsii biomass waste. It was shown that these NPs possess prominent antifungal effects against C. albicans, C. glabrata and C. parapsilosis reference strains. Further detailed studies were performed on C. albicans ATCC 90028. AgNPs kill curve (CFU method and esterase-mediated reduction of fluorescein diacetate); fractionally inhibitory concentration index (FICI) with fluconazole (FLC); effect on fungal cell membrane permeability (propidium iodide (PI) staining), membrane lipids profile (HPLC-MS), yeast morphotypes and intracellular reactive oxygen species level (H2DCFDA probe) were investigated...
2018: PloS One
Ariel S Oliveira, Drauzio E N Rangel
Little is known about the phenotypic effects of hypoxia and transient anoxia on the virulence of an entomopathogenic fungus. Conidia of Metarhizium robertsii were produced on: 1) potato dextrose agar medium (PDA) under normoxia; 2) PDA medium under continuous hypoxia; 3) PDA medium under transient anoxia; and 4) minimal medium with lactose (MML) under normoxia. Conidia produced under transient anoxia and produced on MML were the most virulent to Tenebrio molitor. Conidia produced under normoxia and hypoxia were the least virulent...
March 9, 2018: Journal of Invertebrate Pathology
Abid Hussain
Metarhizium species are the leading bio-control agents well characterized regarding pathogenicity to agricultural, forest, public health, stored grains and urban insect pests. They infect the target host through the tight conidial adherence with the insect cuticle. Conidial binding to the insect cuticle drive the systematic integrated disease development events in target host to impart pathogenesis. However, there is growing evidence that virulence of the pathogen is directly related with proteolytic enzymes including metalloproteinases, chymotrypsin-like proteinases and subtilisin-like proteinases...
January 1, 2018: Virulence
E A Chertkova, E V Grizanova, I M Dubovskiy
Dopamine (DA) is known as a hormone neurotrasnmitter molecule involved in several stress reactions in both vertebrates and invertebrates. Following infections with the fungi Metarhizium robertsii or Beauveria bassiana and the bacterium Bacillus thuringiensis, dopamine the concentration was measured at different time points in the haemolymph of the Colorado potato beetle, Leptinotarsa decemlineata and the larvae of the greater wax moth Galleria mellonella. The infection with M. robertsii increased (4 to 12-fold) DA concentrations in the haemolymph of the potato beetle larvae and the oral infection by B...
February 28, 2018: Journal of Invertebrate Pathology
Ronaldo A Pereira-Junior, Carla Huarte-Bonnet, Flávia R S Paixão, Donald W Roberts, Christian Luz, Nicolás Pedrini, Éverton K K Fernandes
AIMS: The effect of nutritional supplementation of two Metarhizium species with riboflavin (Rb) during production of conidia was (a) evaluated on conidial tolerance (based on germination) to UV-B radiation and (b) on conidial expression following UV-B irradiation, of enzymes known to be active in photoreactivation, viz., photolyase (Phr), laccase (Lcc) and polyketide synthase (Pks). METHODS AND RESULTS: Metarhizium acridum (ARSEF 324) and Metarhizium robertsii (ARSEF 2575) were grown either on (a) potato dextrose agar medium (PDA), (b) PDA supplemented with 1% yeast extract (PDAY), (c) PDA supplemented with Rb (PDA+Rb), or (d) PDAY supplemented with Rb (PDAY+Rb)...
February 23, 2018: Journal of Applied Microbiology
Guillaume Desoubeaux, Anne Debourgogne, Nathan P Wiederhold, Marie Zaffino, Deanna Sutton, Rachel E Burns, Salvatore Frasca, Michael W Hyatt, Carolyn Cray
Fusarium spp. are saprobic moulds that are responsible for severe opportunistic infections in humans and animals. However, we need epidemiological tools to reliably trace the circulation of such fungal strains within medical or veterinary facilities, to recognize environmental contaminations that might lead to infection and to improve our understanding of factors responsible for the onset of outbreaks. In this study, we used molecular genotyping to investigate clustered cases of Fusarium solani species complex (FSSC) infection that occurred in eight Sphyrnidae sharks under managed care at a public aquarium...
October 9, 2017: Medical Mycology: Official Publication of the International Society for Human and Animal Mycology
Xing Zhang, Raymond J St Leger, Weiguo Fang
It is commonly observed that microorganisms subjected to a mild stress develop tolerance not only to higher doses of the same stress, but also to other stresses-a phenomenon called cross protection. The mechanisms for cross protection have not been fully revealed. Here we report that heat shock induced cross protection against UV, oxidative and osmotic/salt stress conditions in the cosmopolitan fungus Metarhizium robertsii. Likewise, oxidative and osmotic/salt stresses also induced cross protection against multiple other stresses...
February 6, 2018: Environmental Microbiology
Thiago Castro, Jørgen Eilenberg, Italo Delalibera
The two-spotted spider mite Tetranychus urticae is an important pest of strawberry crops in Brazil and many other countries. Focus for biocontrol studies involving entomopathogenic fungi has been on three species from the genus Metarhizium: M. anisopliae sensu stricto (s.s.), M. brunneum and M. robertsii. Also, the species Beauveria bassiana has been studied for spider mite control and one isolate (ESALQPL63) is commercially available in Brazil. New and undescribed Metarhizium species have been found recently in Brazil and provide a pool of isolates with potential for biocontrol in Brazil and probably also elsewhere...
February 6, 2018: Experimental & Applied Acarology
Abolfazl Masoudi, John Lad Koprowski, Upendra Raj Bhattarai, Dun Wang
Entomopathogenic fungi are considered to be a safe microbiological pesticide alternative to chemical control. Efforts are underway to understand precisely their taxonomy and natural distribution through mycological and biodiversity studies based on molecular markers. Here, we present descriptions of the diversity of the entomopathogenic fungi in the genera Metarhizium and Beauveria found along the elevational gradients of the Qinling subtropical and temperate forests of Shaanxi province in China, using morphological aspects and molecular markers...
February 2018: Applied Microbiology and Biotechnology
Krishnendu Mukherjee, Andreas Vilcinskas
Parasitic fungi are the only pathogens that can infect insect hosts directly through their proteinaceous exoskeleton. Penetration of the cuticle requires the release of fungal enzymes, including proteinases, which act as virulence factors. Insects can sense fungal infections and activate innate immune responses, including the synthesis of antifungal peptides and proteinase inhibitors that neutralize the incoming proteinases. This well-studied host response is epigenetically regulated by histone acetylation/deacetylation...
November 23, 2017: Virulence
Yixiong Chen, Bing Li, Kai Cen, Yuzhen Lu, Siwei Zhang, Chengshu Wang
Phosphatidylcholine (PC) plays an important role in maintaining membrane integrity and functionality. In this study, two key genes (Mrpct and Mrpem) putatively involved in the cytidine diphosphate (CDP)-choline and phosphatidylethanolamine N-methyltransferase (PEMT) pathways for PC biosynthesis were characterized in the insect pathogenic fungus Metarhizium robertsii. The results indicated that disruption of Mrpct did not lead to any reduction of total PC content but impaired fungal virulence and increased cellular accumulation of triacylglycerol...
January 2018: Environmental Microbiology
Na Guo, Ying Qian, Qiangqiang Zhang, Xiaoxuan Chen, Guohong Zeng, Xing Zhang, Wubing Mi, Chuan Xu, Raymond J St Leger, Weiguo Fang
Metarhizium robertsii is a versatile fungus with saprophytic, plant symbiotic and insect pathogenic lifestyle options. Here we show that M. robertsii mediates the saprophyte-to-insect pathogen transition through modulation of the expression of a membrane protein, Mr-OPY2. Abundant Mr-OPY2 protein initiates appressorium formation, a prerequisite for infection, whereas reduced production of Mr-OPY2 elicits saprophytic growth and conidiation. The precise regulation of Mr-OPY2 protein production is achieved via alternative transcription start sites...
November 16, 2017: Nature Communications
Sebastian A Pelizza, Santiago Schalamuk, María R Simón, Sebastian A Stenglein, Suani G Pacheco-Marino, Ana C Scorsetti
Rachiplusia nu (Guenée) (Lepidoptera: Noctuidae) is one of the major lepidopteran pests defoliating soybeans (Glycine max Merrill) in Argentina. The combined use of chemical insecticides and entomopathogenic fungi is a promising pest-control option to minimize adverse chemical effects. In this work, we evaluated the interactions between five insecticides-two being considered biorational-and five fungal entomopathogenic strains under laboratory conditions in order to determine the possible usefulness of combinations of these agents against R...
October 24, 2017: Revista Argentina de Microbiología
Carla Huarte-Bonnet, Suresh Kumar, Mario C N Saparrat, Juan R Girotti, Marianela Santana, John E Hallsworth, Nicolás Pedrini
Several filamentous fungi are able to concomitantly assimilate both aliphatic and polycyclic aromatic hydrocarbons that are the biogenic by-products of some industrial processes. Cytochrome P450 monooxygenases catalyze the first oxidation reaction for both types of substrate. Among the cytochrome P450 (CYP) genes, the family CYP52 is implicated in the first hydroxylation step in alkane-assimilation processes, while genes belonging to the family CYP53 have been linked with oxidation of aromatic hydrocarbons...
September 23, 2017: Applied Biochemistry and Biotechnology
Xing Zhang, Raymond J St Leger, Weiguo Fang
Heat tolerance is well known to be key to fungal survival in many habitats, but our mechanistic understanding of how organisms adapt to heat stress is still incomplete. Using Metarhizium robertsii, an emerging model organism for assessing evolutionary processes, we report that pyruvate is in the vanguard of molecules that scavenge heat-induced reactive oxygen species (ROS). We show that, as well as inducing a rapid burst of ROS production, heat stress also downregulates genes for pyruvate consumption. The accumulating pyruvate is the fastest acting of several M...
September 5, 2017: MBio
Xinggang Liao, Brian Lovett, Weiguo Fang, Raymond J St Leger
The plant root colonizing insect-pathogenic fungus Metarhizium robertsii has been shown to boost plant growth, but little is known about the responsible mechanisms. Here we show that M. robertsii promotes lateral root growth and root hair development of Arabidopsis seedlings in part through an auxin [indole-3-acetic acid (IAA)]-dependent mechanism. M. robertsii, or its auxin-containing culture filtrate promoted root proliferation, activated IAA-regulated gene expression and rescued the root hair defect of the IAA-deficient rhd6 Arabidopsis mutant...
July 15, 2017: Microbiology
Vadim Kryukov, Olga Yaroslavtseva, Maksim Tyurin, Yuriy Akhanaev, Evgeniy Elisaphenko, Ting-Chi Wen, Oksana Tomilova, Yuri Tokarev, Viktor Glupov
Thirty-four isolates of Metarhizium spp. from Russian collections were genotyped using 5' EF-1α gene sequence analysis. Four species were identified, of which M. robertsii and M. brunneum were the most frequent, whereas M. anisopliae and M. pemphigum were sporadic. Radial growth studies in the temperature range of 10-40°C revealed that growth at high temperatures (35-37.5°C) was inherent for M. robertsii isolates but not for M. brunneum isolates. In contrast, M. brunneum isolates were more active at cold temperatures (10°C) compared to M...
October 2017: Journal of Invertebrate Pathology
Paulina Siewiera, Sylwia Różalska, Przemysław Bernat
Dibutyltin (DBT) is a global pollutant characterized by pro-oxidative properties. The fungal strain Metarhizium robertsii can eliminate high levels of DBT efficiently. In this study, induction of oxidative stress as well as its alleviation through the application of natural estrogens during the elimination of DBT by M. robertsii were evaluated. During the first 24 h of incubation, the initial concentration of DBT (20 mg l(-1)) was reduced to 3.1 mg l(-1), with simultaneous formation of a major byproduct - monobutyltin (MBT)...
October 2017: Chemosphere
Stephen A Rehner, Ryan M Kepler
An essential first step to elucidating the ecology and life histories of Metarhizium anisopliae-group species as entomopathogens, endophytes and soil-adapted fungi is the ability to define species limits and confidently infer a species phylogeny. In a multilocus phylogeny of the core Metarhizium anisopliae species complex, the majority of isolates sampled herein group within the currently defined limits of M. pingshaense, M. anisopliae, M. robertsii and M. brunneum, designated informally as the "PARB" clade...
September 2017: Journal of Invertebrate Pathology
Carl N Keiser, Svjetlana Vojvodic, Imani O Butler, Elizabeth Sartain, Volker H W Rudolf, Julia B Saltz
The success of social living can be explained, in part, by a group's ability to execute collective behaviors unachievable by solitary individuals. However, groups vary in their ability to execute these complex behaviors, often because they vary in their phenotypic composition. Group membership changes over time due to mortality or emigration, potentially leaving groups vulnerable to ecological challenges in times of flux. In some societies, the loss of important individuals (e.g., leaders, elites, queens) may have an especially detrimental effect on groups' ability to deal with these challenges...
May 18, 2017: Journal of Animal Ecology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"