| mycoplasma-like structures in the aquatic fungus aphanomyces astaci. | the hyphae of a nonzoosporulating strain of aphanomyces astaci contain numerous structures which most closely resemble published micrographs of certain mycoplasmas. two normal strains of the same species do not contain these mycoplasma-like bodies. | 1974 | 4128792 |
| the host-parasite relationship between freshwater crayfish and the crayfish disease fungus aphanomyces astaci: responses to infection by a susceptible and a resistant species. | | 1970 | 5488468 |
| the effect of fungicides on survival of the crayfish plague fungus, aphanomyces astaci, oomycetes, growing on fish scales. | zoospores from the crayfish plague fungus aphanomyces astaci could germinate and grow in vitro on scales of salmo salar. the fungicidal activity of different compounds was tested against the fungus growing on fish scales as well as in lake water. malachite green was the most effective fungicide, but scale mucus protected the fungus from this compound to some extent. for complete inhibition of spore germination in scale mucus 2 mg1-1 was required compared to 1 1 mg1-1 in lake water. | 1980 | 7464900 |
| characterization of aphanomyces invadans isolates using pyrolysis mass spectrometry (pyms). | twenty-one isolates of aphanomyces invadans, the fungal pathogen associated with the asian fish disease epizootic ulcerative syndrome (eus), were compared with other oomycete fungi in terms of their pyrolysis mass spectrometry (pvms) profiles. canonical variate analysis (cva) of the pyrolysis mass spectra distinguished the aphanomyces species from a wide scatter of achlya and saprolegnia isolates. further cva and hierarchal cluster analysis (hca) separated the aphanomyces species into two main g ... | 2001 | 11766103 |
| detection of genomic dna of the crayfish plague fungus aphanomyces astaci (oomycete) in clinical samples by pcr. | a diagnostic procedure, based on a polymerase chain reaction method (pcr) was developed to detect infection of crayfish with the oomycete aphanomyces astaci. a set of oligonucleotide primers was designed to specifically amplify a. astaci dna in the its region surrounding the 5.8s rdna gene. the pcr amplifies a 115bp amplicon. the specificity of the primers was demonstrated by testing on 27 a. astaci strains and against 20 non-a. astaci oomycetes and 5 fungal species. most of the non-a. astaci oo ... | 2004 | 15145505 |
| physiological and genetic characterisation of some new aphanomyces strains isolated from freshwater crayfish. | five aphanomyces strains were isolated during suspected outbreaks of crayfish disease in spain and italy. genetic and physiological evidence show that the strains isolated from the freshwater crayfish procambarus clarkii and pacifastacus leniusculus, do not fit into any previously identified group of aphanomyces astaci and are not capable of killing crayfish following standardised experimental infection. rapd-pcr and its sequencing analysis show a high degree of similarity between the new isolat ... | 2004 | 15530744 |
| [water fungi occurence in the water reservoir in zarzeczany of podlasie province]. | studies on the occurrence of aquatic microorganisms in the newest water reservoir zarzeczany village were carried out in years 2001-2004. hydro chemical analysis was performed using standard methods. bait method was used to isolate the fungi. in the reservoir 52 fungi species were identified: fish pathogenic achlya debaryana, a. polyandra, aphanomyces laevis, dictyuchus monosporus, d. sterile, saprolegnia ferax, s. monoica, s. parasitica, human pathogenic candida albicans, c. tropicalis and tric ... | 2004 | 16865972 |
| a quantitative taqman mgb real-time polymerase chain reaction based assay for detection of the causative agent of crayfish plague aphanomyces astaci. | here we present the development and first validation of a taqman minor groove binder (mgb) real-time polymerase chain reaction (rt-pcr) method for quantitative and highly specific detection of aphanomyces astaci, the causative agent of crayfish plague. the assay specificity was experimentally assessed by testing against dna representative of closely related oomycetes, and theoretically assessed by additional sequence similarity analyses comparing the primers and probe sequences to available sequ ... | 2009 | 19201113 |
| identification of two gh18 chitinase family genes and their use as targets for detection of the crayfish-plague oomycete aphanomyces astaci. | the oomycete aphanomyces astaci is regarded as the causative agent of crayfish plague and represents an evident hazard for european crayfish species. native crayfish populations infected with this pathogen suffer up to 100% mortality. the existence of multiple transmission paths necessitates the development of a reliable, robust and efficient test to detect the pathogen. currently, a. astaci is diagnosed by a pcr-based assay that suffers from cross-reactivity to other species. we developed an al ... | 2009 | 19719847 |
| detection and quantification of the crayfish plague agent in natural waters: direct monitoring approach for aquatic environments. | aphanomyces astaci, a specialised parasite of north american freshwater crayfish, is the disease agent of crayfish plague that is lethal to european freshwater crayfish. the life cycle of a. astaci has been inferred from experimental laboratory studies, but less is known about its natural sustainability and ecology. to address such questions, tools for monitoring of a. astaci directly in aquatic environments are needed. here, we present an approach for detecting and quantifying a. astaci directl ... | 2011 | 21797031 |
| potent infection reservoir of crayfish plague now permanently established in norway. | noble crayfish astacus astacus is threatened in europe due to invasive crayfish carrying the crayfish plague agent aphanomyces astaci. norway is among the last countries in which the introduction of non-indigenous crayfish has been limited through strict legislation practices. however, north american signal crayfish pacifastacus leniusculus were recently discovered in a water-course that has been repeatedly hit by the plague. we mapped the distribution and relative density (catch per unit effort ... | 2011 | 22235597 |
| differing virulence of aphanomyces astaci isolates and elevated resistance of noble crayfish astacus astacus against crayfish plague. | crayfish plague epidemics (caused by aphanomyces astaci) have been causing population collapses among native european crayfish stocks since the late 1800s. recent indirect and direct evidence has shown that its virulence has been variable, with native european crayfish even acting as carriers. we tested the differences in a. astaci virulence under experimental conditions using both psi- and as-genotypes with 3 finnish noble crayfish astacus astacus populations. we infected crayfish with adjusted ... | 2012 | 23269387 |
| re-examination of the prevalence of aphanomyces astaci in north american crayfish populations in central europe by taqman mgb real-time pcr. | we applied quantitative taqman minor groove binder real-time polymerase chain reaction (pcr) on dna isolates from soft abdominal cuticle of 460 north american crayfish orconectes limosus and pacifastacus leniusculus, previously tested for aphanomyces astaci presence by conventional semi-nested pcr. both approaches target the internal transcribed spacers of the pathogen nuclear ribosomal dna, but apply different specific sequence motifs and technologies. the real-time pcr approach seems to provid ... | 2011 | 22303628 |
| spiny-cheek crayfish orconectes limosus carry a novel genotype of the crayfish plague pathogen aphanomyces astaci. | the oomycete aphanomyces astaci causes mass mortalities of european crayfish. different species of north american crayfish, original hosts of this parasite, seem to carry different strains of a. astaci. so far, four distinct genotype groups have been recognised using random amplification of polymorphic dna (rapd-pcr). we succeeded in isolating a. astaci from the spiny-cheek crayfish orconectes limosus, a widespread invader in europe, and confirmed that this species carries a novel a. astaci geno ... | 2011 | 21856310 |
| a comparative study of molecular diagnostic methods designed to detect the crayfish plague pathogen, aphanomyces astaci. | crayfish plague is the most important disease of freshwater crayfish with a significant impact on european species. we compared the analytical test sensitivity and specificity of three published pcr assays for the detection of aphanomyces astaci, the causative agent of crayfish plague: a conventional pcr assay targeting the its region and two taqman(®) real time assays, targeting either the its region or the chitinase gene. we also tested a variation of the conventional assay, by changing one of ... | 2011 | 21763084 |
| proteinase inhibitory activities of two two-domain kazal proteinase inhibitors from the freshwater crayfish pacifastacus leniusculus and the importance of the p(2) position in proteinase inhibitory activity. | serine proteinase inhibitors are found ubiquitously in living organisms and involved in homeostasis of processes using proteinases as well as innate immune defense. two two-domain kazal-type serine proteinase inhibitors (kpis), kpi2 and kpi8, have been identified from the hemocyte cdna library of the crayfish pacifastacus leniusculus. unlike other kpis from p. leniusculus, they are found specific to the hemocytes and contain an uncommon p(2) amino acid residue, gly. to unveil their inhibitory ac ... | 2010 | 20621193 |
| confirmation of crayfish plague in italy: detection of aphanomyces astaci in white clawed crayfish. | in the summer of 2009, high levels of mortality among white clawed crayfish austropotamobius pallipes were observed in 3 watercourses of central italy. pcr and culture methods were used to detect the causative agent of the disease. two strains of aphanomyces spp. were isolated and identified by pcr and dna sequencing as aphanomyces astaci and a. repetans. this is the first crayfish plague outbreak in italy to be confirmed by the isolation in culture of a pathogen from austropotamobius pallipes. | 2010 | 20481093 |
| prevalence of the crayfish plague pathogen aphanomyces astaci in invasive american crayfishes in the czech republic. | in central europe invasive north american crayfishes are carriers of the oomycete aphanomyces astaci, which causes crayfish plague. this lethal disease currently represents one of the major threats to native european crayfishes. we used molecular methods-species--specific amplification and sequencing of the pathogen dna--to investigate the prevalence of individuals latently infected with a. astaci in 28 populations of two invasive american crayfish species (6 of the signal crayfish [pacifastacus ... | 2009 | 19459897 |
| detection of aphanomyces astaci in north american crayfish by polymerase chain reaction. | we present a pcr based method to detect aphanomyces astaci in north american crayfish. primers were designed to specifically amplify parts of the internal transcribed spacer (its) regions and the 5.8 rrna gene of a. astaci. a single round and a semi-nested assay were tested for their sensitivity and specificity. specificity of the pcr assays was tested against several closely related aphanomyces species, other oomycetes and some non-a. astaci dna that might be found in or on crayfish. the single ... | 2006 | 17067073 |
| host prophenoloxidase expression in freshwater crayfish is linked to increased resistance to the crayfish plague fungus, aphanomyces astaci. | the crayfish plague (aphanomyces astaci) susceptible freshwater crayfish astacus astacus and the resistant species pacifastacus leniusculus were compared with respect to differential haemocyte count and expression of prophenoloxidase and peroxinectin. a major difference found was that resistant crayfish continuously produced high levels of prophenoloxidase (propo) transcripts and that these levels could not be further increased, whereas in susceptible crayfish propo transcript levels and resista ... | 2003 | 12713493 |
| transmission of crayfish plague. | two possible means of transmission of crayfish plague were investigated: via fish (as vectors), and via crayfish (as hosts or vectors when dead). the crayfish transmission experiments focussed on both the viability of the fungus in dead crayfish when kept in simulated field conditions, and on the treatments which kill viable forms of aphanomyces astaci within the recently dead host (cadaver). it was found that a. astaci remains viable for 5 d, and possibly longer in crayfish kept in water at 21 ... | 2002 | 12542093 |
| analysis of chitinase expression in the crayfish plague fungus aphanomyces astaci. | chitinase, as determined by enzymatic activity in the growth medium and by transcription of the chitinase gene aachi1, is expressed at a high level during vegetative growth of the crayfish pathogen aphanomyces astaci and expression is not further stimulated by chitin. expression is not detected in zoospores and it does not increase to high levels until late during germination. upon sporulation, chitinase expression increases to levels comparable with those seen in fast-growing mycelium. this pat ... | 2002 | 12363086 |
| identification of the crayfish plague fungus aphanomyces astaci by polymerase chain reaction and restriction enzyme analysis. | to characterise the dna of the crayfish plague fungus aphanomyces astaci, saprolegniales (oomycetes), primers were developed to amplify a 1050bp segment of the 28s rdna region. restriction enzymes were applied to the amplicon obtained, to distinguish a. astaci from 12 fungal species belonging also to the saprolegniales and five more distantly related fungi. most of the fungal species included in the study are either known parasites of freshwater crayfish cuticle or can be found in their natural ... | 2002 | 11844624 |
| molecular cloning and characterization of two serine proteinase genes from the crayfish plague fungus, aphanomyces astaci. | two novel genes encoding the serine proteinases, subtilisin (aasp1) and trypsin (aasp2), from aphanomyces astaci were identified. based on the amino acidconsensus sequences around the catalytic triad of these serine proteinases, degenerated oligonucleotides were designed for isolation of serine proteinase genes from a genomic dna library. the aasp1 gene encodes a full-length protein of 515 amino acids as a large precursor of 56 kda. after cleavage of a predicted leader sequence of 18 residues an ... | 2001 | 11356056 |
| defence reactions in and susceptibility of australian and new guinean freshwater crayfish to european-crayfish-plague fungus. | the deposition of melanin of the surface of the cell wall of the crayfish-plague fungus, aphanomyces astaci, in infected cuticles of australian crayfish seemed to be correlated with some degree of resistance to infection. the most obvious reactions towards the fungal structures present in the blood in vivo were their encapsulation by blood cells, many which then disintegrated. this was followed by melanization of the fungal surface. crayfish blood inhibited completely hyphal growth in vitro and ... | 1976 | 820321 |
| cyst and germ tube wall structure in aphanomyces astaci, oomycetes. | aphanomyces astaci secondary cyst walls and walls of germinating spores were prepared by alkaline hydrolysis, autolysis, sonication, and enzymic degradation and were examined by shadow-casting and negative-staining techniques. the cyst wall consists of randomly oriented fibrils, about 3 nm in diameter. the fibrils are embedded in, or covered by, amorphous beta-1,3-glucans which can easily be removed by alkaline hydrolysis. the germ tube wall surface has the same structure, but the amorphous laye ... | 1978 | 743640 |
| activation of serum prophenoloxidase in arthropod immunity. the specificity of cell wall glucan activation and activation by purified fungal glycoproteins of crayfish phenoloxidase. | this study shows that the activation of crayfish serum prophenoloxidase by carbohydrates was specific for beta-1,3-glucans. fractionation of the beta-1,3-glucan laminaran into laminaran m and laminaran g showed that both activated the proenzyme, but the g-chain had somewhat higher affinity for the proenzyme. methylation analysis of these two fractions revealed that there were no 1,6-linkages present. laminaripentaose, a linear pentasaccharide composed of (1 leads to 3)-linked beta-d-glucopyranos ... | 1979 | 110434 |