scholarly journals Interaction between the nematophagous fungusDuddingtonia flagransand infective larvae ofHaemonchus contortus(Nematoda: Trichostrongyloidea)

2008 ◽  
Vol 82 (4) ◽  
pp. 337-341 ◽  
Author(s):  
A.K. Campos ◽  
J.V. Araújo ◽  
M.P. Guimarães
Keyword(s):  
Electron Microscopy ◽  
Haemonchus Contortus ◽  
Scanning Electron Micrographs ◽  
Duddingtonia Flagrans ◽  
Larval Cuticle ◽  
Infective Larvae ◽  
Dialysis Membranes ◽  
Nematode Cuticle ◽  
Scanning Electron

AbstractThe interaction betweenDuddingtonia flagransand infective larvae ofHaemonchus contortuswas studiedin vitrounder optical and scanning electron microscopy. Trap formation by the fungus started 9 hours after inoculation and first larvae were found 11 hours after larval inoculation on colonies grown on the surface of dialysis membranes. Scanning electron micrographs were taken 12, 24, 36 and 48 h after larval predation. Details of predation structures and fungus–larvae interaction are described. A mucilaginous substance occurred at the points of adherence of traps to nematode cuticle. Bacteria were also found at some points of interaction between fungus and larval cuticle. Cuticle penetration by fungus hyphae occurred only 48 h after predation.

scholarly journals Fungal Antagonism Assessment of Predatory Species and Producers Metabolites and Their Effectiveness onHaemonchus contortusInfective Larvae

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Manoel Eduardo Silva ◽  
Fabio Ribeiro Braga ◽  
Pedro Mendoza de Gives ◽  
Jair Millán-Orozco ◽  
Miguel Angel Mercado Uriostegui ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Antagonistic Effect ◽  
Nematophagous Fungi ◽  
Duddingtonia Flagrans ◽  
Clonostachys Rosea ◽  
Infective Larvae ◽  
Fungal Isolates ◽  
Show Evidence ◽  
Fungal Antagonism

The objective of this study was to assess antagonism of nematophagous fungi and species producers metabolites and their effectiveness onHaemonchus contortusinfective larvae (L3). Assay A assesses the synergistic, additive, or antagonistic effect on the production of spores of fungal isolates of the speciesDuddingtonia flagrans,Clonostachys rosea,Trichoderma esau, andArthrobotrys musiformis; Assay B evaluates in vitro the effect of intercropping of these isolates grown in 2% water-agar (2% WA) on L3ofH. contortus.D. flagrans(Assay A) produced 5.3 × 106spores and associated withT. esau,A. musiformis, orC. roseareduced its production by 60.37, 45.28, and 49.05%, respectively.T. esauproduced 7.9 × 107conidia and associated withD. flagrans,A. musiformis, orC. roseareduced its production by 39.24, 82.27, and 96.96%, respectively.A. musiformisproduced 7.3 × 109spores and associated withD. flagrans,T. esau, orC. roseareduced its production by 99.98, 99.99, and 99.98%, respectively.C. roseaproduced 7.3 × 108conidia and associated withD. flagrans,T. esau, orA. musiformisreduced its production by 95.20, 96.84, and 93.56%, respectively. These results show evidence of antagonism in the production of spores between predators fungi.

scholarly journals Nematicidal Effect and Histological Modifications Induced by Hydrolysable Tannin Extract on the Third-Stage Infective Larvae of Haemonchus contortus

Biology ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 442
Author(s):  
Perla María del Carmen Acevedo-Ramírez ◽  
Claudia Hallal-Calleros ◽  
Iván Flores-Pérez ◽  
Fernando Alba-Hurtado ◽  
María Berenit Mendoza-Garfias ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Haemonchus Contortus ◽  
Effective Control ◽  
Tannin Extract ◽  
Physical Damage ◽  
Hydrolysable Tannin ◽  
Green Production ◽  
Scanning Electron

Haemonchus contortus is the most frequent and most important nematode parasite in the ruminants production of tropical and subtropical regions. There are strains resistant to all families of available anthelmintics. Consequently, the conduction of research to find other resources that allow effective control of this parasitic disease, preferably focusing on green production, is necessary. The aim of this study was to evaluate the effect of hydrolysable tannin extract (HTE) on larvae 3 (L3) of H. contortus in vitro. L3 were exposed to different HTE concentrations and times. In addition, both light and scanning electron microscopy were used to explore physical damage on L3 subjected to HTE activity. After 72 h of incubation, the mean lethal concentration of HTE was 2 mg/mL; this concentration has been previously referred to as safe for consumption in cattle. Scanning electron microscopy revealed H. contortus L3 destruction, damage was evident by separation of the sheath mainly in the cervical and caudal regions of the larva and by rupture of the cuticle with larval evisceration. Our results suggest that hydrolysable tannin extract from chestnut could be considered as a green alternative for parasitic control in ruminants.

scholarly journals Activity in vitro of fungal conidia of Duddingtonia flagrans and Monacrosporium thaumasium on Haemonchus contortus infective larvae

2010 ◽  
Vol 85 (2) ◽  
pp. 138-141 ◽  
Author(s):  
A.R. Silva ◽  
J.V. Araújo ◽  
F.R. Braga ◽  
C.D.F. Alves ◽  
L.N. Frassy
Keyword(s):  
Haemonchus Contortus ◽  
Control Group ◽  
Duddingtonia Flagrans ◽  
Control Groups ◽  
Infective Larvae ◽  
Fungal Isolates ◽  
Petri Dishes ◽  
And Control ◽  
Baermann Method

AbstractThe objective of this work was to evaluate the predatory activity of the fungi Duddingtonia flagrans (AC001) and Monacrosporium thaumasium (NF34a) on Haemonchus contortus infective larvae (L3) in two experimental assays (A and B). In assay A, two treatments and one control were formed and kept for 7 days in Petri dishes with 2% water-agar. Each treatment consisted of 1000 H. contortus L3 and 1000 conidia of only one fungal isolate, and the control group consisted of 1000 L3, without fungus, with 10 repetitions per group. In assay B, 1000 conidia of one of the fungal isolates, AC001 or NF34a, were added to coprocultures made from 20 g of faeces collected from sheep naturally infected with H. contortus. At the end of the experiment, the Baermann method was used to count the non-predated larvae of all Petri dishes from treatment and control groups. In assay A, no difference was observed (P>0.05) between the groups treated with AC001 and NF34a fungi. A difference was observed (P < 0.05) between the treated and control groups. The L3 reduction percentages at the end of the experiment were 87.75 and 85.57%, respectively, for the fungal isolates compared to the control group. In assay B, the reduction percentages for conidia of these isolates were 85.82 and 87.32%, respectively. The results obtained show that D. flagrans (AC001) and M. thaumasium (NF34a) were effective in the in vitro control of sheep H. contortus L3 and could be used in the biological control of this nematode.

Scanning electron microscopy of Haemonchus contortus exposed to tannin-rich plants under in vivo and in vitro conditions

2013 ◽  
Vol 133 (3) ◽  
pp. 281-286 ◽  
Author(s):  
C. Martínez-Ortíz-de-Montellano ◽  
C. Arroyo-López ◽  
I. Fourquaux ◽  
J.F.J. Torres-Acosta ◽  
C.A. Sandoval-Castro ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Haemonchus Contortus ◽  
Scanning Electron

The nematode-trapping efficacy of two chlamydospore-forming fungi against Haemonchus contortus in sheep

2005 ◽  
Vol 79 (4) ◽  
pp. 315-319 ◽  
Author(s):  
J.B. Chauhan ◽  
P.K. Sanyal ◽  
R.B. Subramanian
Keyword(s):  
Biological Control ◽  
Haemonchus Contortus ◽  
Antagonistic Effect ◽  
Parasitic Nematodes ◽  
Duddingtonia Flagrans ◽  
Infective Larvae ◽  
Third Stage ◽  
Indian Isolates ◽  
Set Up

AbstractAn in vitro study was carried out to determine efficacy of Indian isolates of the nematode-trapping fungi Arthrobotrys musiformis and Duddingtonia flagrans to capture infective larvae of Haemonchus contortus. These fungi have previously been screened and selected for their survival in the gastrointestinal tract of sheep without losing growth and nematode capturing potential. Following the feeding of chlamydospores of these two fungi alone or in combination in sheep experimentally infected with Haemonchus contortus, coprocultures were set up to enumerate the infective third stage larvae. The number of larvae captured from faeces of fungus-fed sheep was significantly higher compared with fungus-unfed controls irrespective of the fungus used. The fungal combination produced no antagonistic effect and thus can be used as efficiently as the fungi alone in the biological control of animal parasitic nematodes.

Preparation of biological monolayers for producing high-resolution scanning electron micrographs Code: PLOS2021 [PONE-D-21-26669] - [EMID:f8569bc7b537f6e4] v1

2021 ◽  
Author(s):  
Shireen Mentor ◽  
Franscious Cummings ◽  
David Fisher ◽  
shireen.mentor not provided
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tissue Culture ◽  
High Resolution ◽  
Biological Samples ◽  
Scanning Electron Micrographs ◽  
Mouse Brain Endothelial Cells ◽  
Coating Methods ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides a technical platform for nanoscopic mapping of biological structures. Correct preparation of SEM samples can provide an unprecedented understanding of the nexus between cellular morphology and topography. This comparative study critically examines two coating methods for preparing biological samples for scanning electron microscopy, while also providing novel advice on how to prepare in vitro epithelial or endothelial samples for high-resolution scanning-electron microscopy (HR-SEM). Two obstacles often confront the biologist when investigating cellular structures grown under tissue culture conditions, viz., how to prepare and present the biological samples to the HR-SEM microscope without affecting topographical membrane and cellular structural alterations. Firstly, our use of the Millicell cellulose inserts on which to grow our cellular samples in preparation for HR-SEM is both novel and advantageous to comparing the permeability function of cells to their morphological function. Secondly, biological material is often non-conducting, thermally sensitive and fragile and, therefore, needs to be fixed correctly and coated with thin conducting metal to ensure high-resolution detail of samples. Immortalized mouse brain endothelial cells (bEnd5) was used as a basis for describing the preferences in the use of the protocol. We compare two biological sample coating modalities for the visualizing and analysis of texturized, topographical, membranous ultrastructures of brain endothelial cell (BEC) confluent monolayers, namely, carbon and gold:palladium (Au:Pd) sputter coating in preparation for HR-SEM. BEC monolayers sputter-coated with these two modalities produced three-dimensional micrographs which have distinctly different topographical detail from which the nanostructural cellular data can be examined. The two coating methods display differences in the amount of nanoscopic detail that could be resolved in the nanosized membrane cytoarchitecture of BEC monolayers. The micrographical data clearly showed that Au:Pd sputter-coated samples generate descript imagery, providing useful information for profiling membrane nanostructures compared to carbon-coated samples. The recommendations regarding the contrast in two modalities would provide the necessary guidance to biological microscopists in preparing tissue culture samples for HR-SEM.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

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