scholarly journals Nematicidal effect of an Argentine strain of Photorhabdus laumondi laumondi (Enterobacteriaceae) on the free-living nematode Panagrellus redivivus (Rhabditidae: Panagrolaimidae)

Author(s):  
Augusto Salas ◽  
María Fernanda Achinelly ◽  
Diego Herman Sauka
2006 ◽  
Vol 72 (4) ◽  
pp. 2982-2987 ◽  
Author(s):  
Hong Luo ◽  
Xuan Li ◽  
Guohong Li ◽  
Yanbo Pan ◽  
Keqin Zhang

ABSTRACT Efficient killing of nematodes by Stropharia rugosoannulata Farlow ex Murrill cultures was observed. This fungus showed the ability to immobilize the free-living nematode Panagrellus redivivus Goodey within minutes and to immobilize the pine wilt nematode Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle within hours on agar plates. Moreover, P. redivivus worms were completely degraded by the fungus within 24 to 48 h. The cultures of S. rugosoannulata studied shared the characteristic of abundantly producing cells with finger-like projections called acanthocytes. We showed that the nematode-attacking activity of this fungus is carried out by these spiny acanthocytes and that mechanical force is an important factor in the process. Furthermore, the growth and nematode-attacking activity of the fungus in soil were also determined, and our results suggest that acanthocytes are functional in soil.


Parasitology ◽  
1995 ◽  
Vol 110 (4) ◽  
pp. 449-455 ◽  
Author(s):  
L. Holden-Dye ◽  
C. J. Franks ◽  
R. G. Williams ◽  
R. J. Walker

SUMMARYThe action of two peptides isolated from the nematode Panagrellus redivivus, PF1 (SDPNFLRFamide) and PF2 (SADPNFLRFamide) have been studied on synaptic transmission in the motornervous system of the parasitic nematode Ascaris suum. Intracellular recordings were made from Ascaris somatic muscle cells and excitatory junction potentials (EJPs) elicited by stimulation of the ventral nerve cord. The EJPs were cholinergic as they were blocked by the Ascaris nicotinic receptor antagonist, benzoquinonium. PF1 caused a slow hyperpolarization, similar to the action of this peptide first reported by Bowman, Geary & Thompson (1990) and further characterized by Franks et al. (1994). The hyper-polarization was accompanied by a marked decrease in the amplitude of the EJPs with an EC50 of 311 ± 30 nM (n = 5). This inhibition is unlikely to be due to a post-synaptic site of action of the peptide as the muscle cell input conductance was not significantly altered by PF1 and furthermore the response to bath-applied acetylcholine was not inhibited by PF1 at concentrations up to 10μM (n = 6). PF2 also inhibited the EJPs in a similar manner to PF1. These studies indicate that both of the peptides isolated from the free-living nematode Panagrellus redivivus have biological activity in the parasitic nematode Ascaris suum. PF1 and PF2 have inhibitory actions in contrast to the predominantly excitatory actions of the Ascaris endogenous peptides AF1 (KNEFIRFamide) and AF2 (KHEYLRFamide). The potent actions of the Panagrellus neuropeptides PF1 and PF2 in Ascaris suggest that peptides with a similar or identical sequence may also occur in Ascarisand have an inhibitory role in the motornervous system.


FEBS Letters ◽  
1989 ◽  
Vol 253 (1-2) ◽  
pp. 76-78 ◽  
Author(s):  
A. Papadopoulos ◽  
P.M. Brophy ◽  
P. Crowley ◽  
M. Ferguson ◽  
J. Barrett

Nematology ◽  
2008 ◽  
Vol 10 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Li Cao ◽  
Xuehong Qiu ◽  
Xiaofen Liu ◽  
Xiuling Liu ◽  
Richou Han

Abstract Xenorhabdus and Photorhabdus bacteria are symbionts of entomopathogenic nematodes of the genera Steinernema and Heterorhabditis, respectively. To determine the nutrient potential of these bacteria for a free-living nematode, Panagrellus redivivus, a promising food source for first-feeding fish and crustacean, sterile first-stage juveniles (J1) of P. redivivus were fed on various isolates of Xenorhabdus and Photorhabdus bacteria in liquid cultures. Most of the tested bacterial isolates did not support the growth of P. redivivus. However, four of the Xenorhabdus isolates (X. nematophila All, X. bovienii T319, X. beddingii X-7 and X. poinarii KG) provided nutrients for the production of these nematodes in a liquid medium. Two Xenorhabdus isolates (X. beddingii X-7 and X. poinarii KG) even supported mass production of the nematode in a sponge medium, with yields comparable to those with yeast strains. This is the first report that Xenorhabdus bacteria can function as a nutrient source for mass production of nematodes other than their usual symbiotic partners.


Nematology ◽  
2004 ◽  
Vol 6 (6) ◽  
pp. 783-795 ◽  
Author(s):  
Klaus Becker ◽  
James Dick ◽  
Douglas Tocher ◽  
Christian Schlechtriem

AbstractThe free-living nematode Panagrellus redivivus can be mass produced in monoxenic solid culture on Saccharomyces cerevisiae and therefore could be useful as a live food for marine fish or crustacean larvae in the rapidly expanding aquaculture industry. However, this will depend on their lipid and fatty acid composition and so this was investigated in mass produced P. redivivus grown on S. cerevisiae in three different media. Live nematodes were also incubated with [1-14C]-labelled fatty acids and the desaturation and elongation of the fatty acids were determined. The combined results from the growth trials on different media and the metabolic studies with labelled fatty acids indicated the presence of Δ9, Δ12, Δ6 and Δ5 fatty acid desaturase activities, and elongase activities active towards C18, C16 and shorter chain fatty acids. The presence of Δ15, and therefore the ability to produce n-3 polyunsaturated fatty acids, was suggested by the compositional data, but could not be conclusively established from metabolic studies.


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