Identification of a Novel Secreted Metabolite Cyclo(Phenylalanyl-Prolyl) from Batrachochytrium Dendrobatidis and its effect on Galleria Mellonella.

Author(s):  
Amanda Michelle Starr ◽  
Masoud Zabet-Moghaddam ◽  
Michael San Francisco

Abstract The fungus, Batrachochytrium dendrobatidis, is the causative agent of chytridiomycosis and a leading cause of global decline in amphibian populations . The first stages of chytridiomycosis include: inflammation, hyperkeratosis, lethargy, loss of righting reflex, and disruption of internal electrolyte levels leading to eventual death of the host. Previous work indicates that B. dendrobatidis can produce immunomodulatory compounds and other secreted molecules that regulate the growth of the fungus. In this study, filtrates of the fungus grown in media and water were subjected to ultra performance liquid chromatography-mass spectrometry and analyzed using Compound Discoverer 3.0. Identification of cyclo(phenylalanyl-prolyl), chitobiose, and S-adenosylmethionine were verified by their retention times and fragmentation patterns from B. dendrobatidis supernatants. Previous studies have analyzed the effects of B. dendrobatidis on amphibian models, in vitro, or in cell culture. We studied the effects of live B. dendrobatidis cells, spent culture filtrates containing secreted metabolites, and cyclo(pheylalanyl-prolyl) on wax moth larvae ( Galleria mellonella) . Concentrated filtrates caused melanization within 24 hours, while live B. dendrobatidis caused melanization within 48 hours. Our results indicate B. dendrobatidis produces secreted metabolites previously unreported. These findings provide another alternative for the use of a non-amphibian model system to study pathogenicity traits in this fungus.

2006 ◽  
Vol 387 (5) ◽  
pp. 549-557 ◽  
Author(s):  
Gregor Langen ◽  
Jafargholi Imani ◽  
Boran Altincicek ◽  
Gernot Kieseritzky ◽  
Karl-Heinz Kogel ◽  
...  

Abstract A cDNA encoding gallerimycin, a novel antifungal peptide from the greater wax moth Galleria mellonella, was isolated from a cDNA library of genes expressed during innate immune response in the caterpillars. Upon ectopic expression of gallerimycin in tobacco, using Agrobacterium tumefaciens as a vector, gallerimycin conferred resistance to the fungal pathogens Erysiphe cichoracearum and Sclerotinia minor. Quantification of gallerimycin mRNA in transgenic tobacco by real-time PCR confirmed transgenic expression under control of the inducible mannopine synthase promoter. Leaf sap and intercellular washing fluid from transgenic tobacco inhibited in vitro germination and growth of the fungal pathogens, demonstrating that gallerimycin is secreted into intercellular spaces. The feasibility of the use of gallerimycin to counteract fungal diseases in crop plants is discussed.


2000 ◽  
Vol 93 (3) ◽  
pp. 837-843 ◽  
Author(s):  
Robert Dickinson ◽  
Ian White ◽  
William R. Lieb ◽  
Nicholas P. Franks

Background Although it is accepted widely that optically active intravenous general anesthetics produce stereoselective effects in animals, the situation regarding volatile agents is confused. Conventional studies with scarce isoflurane enantiomers have been limited to small numbers of animals and produced conflicting results. By injecting these volatile enantiomers intravenously, however, it is possible to study large numbers of animals and obtain reliable results that can help to identify the molecular targets for isoflurane. Methods Pure isoflurane enantiomers were administered intravenously to rats after solubilization in a lipid emulsion. The ability of each enantiomer to produce a loss of righting reflex was determined as a function of dose, and quantal dose-response curves were constructed. In addition, sleep times were recorded with each enantiomer. Chiral gas chromatography was used to measure relative enantiomer concentrations in the brains of rats injected with racemic isoflurane. Results The S(+)-enantiomer was 40 +/- 8% more potent than the R(-)-enantiomer at producing a loss of righting reflex. The S(+)-enantiomer induced longer sleep times (by about 50%) than did the R(-)-enantiomer. Rats anesthetized by a dose of racemic isoflurane sufficient to achieve a half-maximal effect had essentially identical brain concentrations of the two enantiomers. Conclusions The S(+)-enantiomer of the general anesthetic isoflurane is significantly (P < 0.001) more potent than the R(-)-enantiomer at causing a loss of righting reflex in rats. This confirms the view that isoflurane acts by binding to chiral sites. The observed degree of stereoselectivity provides a useful guide for ascertaining from in vitro experiments which molecular targets are most likely to play major roles in the loss of righting reflex caused by isoflurane.


Sociobiology ◽  
2020 ◽  
Vol 67 (1) ◽  
pp. 89
Author(s):  
Daniele Maria Telles ◽  
Gabriel Moreno Martineli ◽  
Maurice Fabian Scaloppi ◽  
Marina Pagliai Ferreira Luz ◽  
Samir Moura Kadri ◽  
...  

Honey bees (Apis mellifera L.) have great global socioeconomic and environmental importance. However, the greater wax moth (Galleria mellonella L.) is a pest that causes serious worldwide damage to honey bee colonies. Good beekeeping practices and physical, chemical, or natural methods can be used to control wax moths. The use of natural products is a more sustainable option because of their lower toxicity to the environment and the colony. Therefore, we evaluated the efficiency of four natural products for greater wax moth control: neem oil (Azadirachta indica), eucalyptus oil (Eucalyptus spp.), tobacco extract (Nicotiana tabacum), and malagueta pepper extract (Capsicum frutescens). We also evaluated their effects on adult bees and on the population growth of colonies. The 4th instar wax moths and adult bees were subjected to in vitro bioassays of different concentrations of the products. The results allowed usto establish a concentration for each product that was safe for the bees and effectively controlled the moth. Then, we sprayed them on bee colonies to evaluate their effects on population growth. The neem and eucalyptus oils caused wax moth mortality at low concentrations, but did not affect colony population growth. However, they did have a toxic effect on adult bees. The tobacco and pepper extracts efficiently controlled the moth, but did not cause adult bee mortality or interfered with the population growth of the colonies. Therefore, the tobacco and pepper extracts could efficiently control the greater wax moth, without damaging honey bees.


Author(s):  
М. G. Markova ◽  
Е. N. Somova

Work on the clonal micropropagation of strawberries comes down to the search for new growth regulators, which include a biologically active substance - the waste product of the wax moth Galleria mellonella L. The effect of the waste product of the wax moth on the efficiency of clonal micropropagation of strawberries (Fragaria х ananassa duch) in vitro and in vivo conditions in 2018-2020 is shown. The object of research is micro-cuttings, rooted micro-cuttings and adapted micro-plants of garden strawberries of the Korona variety and of the remontant strawberries of the Brighton variety. It was revealed that at the proliferation stage, the propagation coefficient of the Korona variety increased significantly with the introduction of the waste product of the wax moth in doses of 4.0 mg/L and 6.0 mg/L and amounted to 4.2 and 3.8 pcs./explant, respectively; for Brighton variety, the coefficient increased significantly when the dose of the waste product of the wax moth 2.0 mg/L and amounted to 4.6 pcs./explant. The introduction of the waste product of the wax moth in doses of 4.0 mg/L and 6.0 mg/L into the nutrient medium had a significant effect on the yield of Brighton micro-cuttings suitable for rooting: the yield was 95.5 and 94.1%, respectively 87.7% in the control. For the Korona variety, no significant positive effect of the waste product of the wax moth on this indicator was noted. The rooting of micro-cuttings of strawberries of both varieties significantly increased with the introduction of the waste product of the wax moth into the nutrient medium in all studied doses and amounted to 86.4-100% in the Korona variety, and 88.9-100% in the Brighton variety.  The survival rate of adaptable micro-cuttings of Corona variety strawberries when sprayed with an aqueous solution of the waste product of the wax moth at a dose of 4.0 mg/L was 100%; the maximum survival rate of micro-cuttings Brighton variety is 99.8% in the variant with spraying with an aqueous solution of the waste product of the wax moth at a dose of 6.0 mg/L.


2009 ◽  
Vol 111 (2) ◽  
pp. 240-249 ◽  
Author(s):  
Joseph F. Cotten ◽  
S Shaukat Husain ◽  
Stuart A. Forman ◽  
Keith W. Miller ◽  
Elizabeth W. Kelly ◽  
...  

Background Etomidate is a rapidly acting sedative-hypnotic that provides hemodynamic stability. It causes prolonged suppression of adrenocortical steroid synthesis; therefore, its clinical utility and safety are limited. The authors describe the results of studies to define the pharmacology of (R)-3-methoxy-3-oxopropyl1-(1-phenylethyl)-1H-imidazole-5-carboxylate (MOC-etomidate), the first etomidate analogue designed to be susceptible to ultra-rapid metabolism. Methods The gamma-aminobutyric acid type A receptor activities of MOC-etomidate and etomidate were compared by using electrophysiological techniques in human alpha1beta2gamma2l receptors. MOC-etomidate's hypnotic concentration was determined in tadpoles by using a loss of righting reflex assay. Its in vitro metabolic half-life was measured in human liver S9 fraction, and the resulting metabolite was provisionally identified by using high-performance liquid chromatography/mass spectrometry techniques. The hypnotic and hemodynamic actions of MOC-etomidate, etomidate, and propofol were defined in rats. The abilities of MOC-etomidate and etomidate to inhibit corticosterone production were assessed in rats. Results MOC-etomidate potently enhanced gamma-aminobutyric acid type A receptor function and produced loss of righting reflex in tadpoles. Metabolism in human liver S9 fraction was first-order, with an in vitro half-life of 4.4 min versus more than 40 min for etomidate. MOC-etomidate's only detectable metabolite was a carboxylic acid. In rats, MOC-etomidate produced rapid loss of righting reflex that was extremely brief and caused minimal hemodynamic changes. Unlike etomidate, MOC-etomidate produced no adrenocortical suppression 30 min after administration. Conclusions MOC-etomidate is an etomidate analogue that retains etomidate's important favorable pharmacological properties. However, it is rapidly metabolized, ultra-short-acting, and does not produce prolonged adrenocortical suppression after bolus administration.


2015 ◽  
Vol 7 (15) ◽  
pp. 6173-6181 ◽  
Author(s):  
Kang An ◽  
Zhang Shengjie ◽  
Shan Jinjun ◽  
Di Liuqing

Ginsenoside Rb1, an ingredient of the herbal medicine Panax ginseng, possesses a variety of biological activities.


2002 ◽  
Vol 97 (4) ◽  
pp. 902-905 ◽  
Author(s):  
Pamela Flood ◽  
James M. Sonner ◽  
Diane Gong ◽  
Kristen M. Coates

Background Neuronal nicotinic acetylcholine receptors (nAChRs) have been implicated in the mechanism of action of isoflurane as they are inhibited at subanesthetic concentrations. Despite clear evidence for nicotinic inhibition at relevant isoflurane concentrations, it is unclear what behavioral result ensues, if any. Methods The authors have modeled two behaviors common to all general anesthetics, immobility and hypnosis, as minimum alveolar concentration that prevents movement in response to a supramaximal stimulus (MAC) and loss of righting reflex (LORR). They have tested the ability of nicotinic pharmacologic modulators and congenital absence of most heteromeric nAChRs to affect concentration of isoflurane required for these behaviors. Results Neither mecamylamine, 5 mg/kg, nor chlorisondamine, 10 mg/kg, affected isoflurane MAC. Nicotine caused a small decrease in MAC. None of the above agents had any effect on the concentration of isoflurane required for LORR. Mice genetically engineered to lack the beta 2 nicotinic gene product were not different in MAC or LORR from controls. Conclusions Nicotinic antagonists do not cause MAC or LORR. Inhibition of nicotinic acetylcholine receptors by isoflurane is not likely related to its ability to provide immobility and hypnosis in a surgical setting. This is perhaps not surprising as the inhibition of nAChRs in vitro is complete at an isoflurane concentration equal to one half of MAC. Nicotinic inhibition may, however, be involved in anesthetic behaviors such as amnesia and analgesia, which occur at lower anesthetic concentrations.


1959 ◽  
Vol 5 (2) ◽  
pp. 203-228 ◽  
Author(s):  
June M. Stephens

Pseudomonas aeruginosa (Schroeter) Migula antigen remained in the blood of larvae of the wax moth, Galleria mellonella (L.), during the resistant period of the insect. Bacterial antigen present in the immune blood produces agglutinating titers in rabbits about 10 times as great as those produced by an approximately equal volume of standard P. aeruginosa vaccine. Attempts to demonstrate the mechanism that enhances the antigen showed that the active portion was contained in the serum, that the action occurred within several hours in vivo and only reached the same level after 3 days in vitro mixture, and that the action was probably not caused by lysis of the bacterial cells and the consequent liberation of more antigen in the blood. Electrophoretic studies on the blood mixture indicated that the altered or enhanced antigen may be bound to a blood fraction, the exact nature of which was not determined. The larvae were actively or passively immunized against lethal doses of P. aeruginosa within 20 to 24 hours. Concentration of vaccine had little effect upon the degree of immunity conferred upon the larvae. The immunity lasted about three days and was more specific than nonspecific. The larvae were not actively protected against P. aeruginosa by introduction of albuminous foreign material into the body cavity. True antibodies were not detectable in the immune blood though the bactericidal action of immune blood was at least twice as great as that of normal blood. Preliminary investigations on immune responses of other lepidopterous insects to P. aeruginosa antigen and of the wax moth to antigens of some other Gram-negative bacteria indicated similar results.


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