| temporal and spatial distribution of paramoebae in the water column--a pilot study. | amoebic gill disease is the main disease affecting the salmonid industry in tasmania, but no information on the distribution of the causative pathogen, neoparamoeba pemaquidensis, in the aquatic environment is available. this pilot study aimed to determine temporal and spatial distributions of paramoebae species in the water column, using an immuno-dot blot technique. water samples were collected from inside fish cages at various depths (0.5, 5.5 and 11.0 m) in both summer and winter, as well as ... | 2003 | 12962231 |
| the induction of laboratory-based amoebic gill disease revisited. | previous work in our laboratory defined a method of inducing laboratory-based amoebic gill disease (agd) in atlantic salmon, salmo salar l. gills of agd-affected fish were scraped and the debris placed into fish-holding systems, eliciting agd in naïve atlantic salmon. while this method is consistently successful in inducing agd, variability in the kinetics and severity of infections has been observed. it is believed that the infections are influenced by inherently variable viability of post-harv ... | 2004 | 15291786 |
| salmonid gill bacteria and their relationship to amoebic gill disease. | 16s ribosomal rna gene analysis was used to assess the bacterial community associated with atlantic salmon, salmo salar l., gills which were either affected by amoebic gill disease (agd) or were agd-negative, in order to determine the role that bacteria may play in the development of agd. agd-positive specimens were either infected in the laboratory with neoparamoeba pemaquidensis, the causative agent of agd, or were obtained from commercial salmon cages. samples from laboratory fish maintained ... | 2004 | 15291790 |
| 18s ribosomal dna-based pcr identification of neoparamoeba pemaquidensis, the agent of amoebic gill disease in sea-farmed salmonids. | neoparamoeba pemaquidensis is a parasomal amoeboid protozoan identified as the agent of amoebic gill disease (agd) in atlantic salmon salmo salar reared in sea-pens in tasmania, australia, and coho salmon oncorhynchus kisutch farmed on the west coast of the usa. outbreaks of agd caused by immunologically cross-reactive paramoebae have also been reported in sea-farmed salmonids in several other countries. complete 18s rdna sequences were determined for respective paramoebae isolated from infected ... | 2004 | 15352525 |
| cultured gill-derived neoparamoeba pemaquidensis fails to elicit amoebic gill disease (agd) in atlantic salmon salmo salar. | amoebic gill disease (agd) affects the culture of atlantic salmon salmo salar in the southeast of tasmania. the disease is characterised by the presence of epizoic neoparamoeba spp. in association with hyperplastic gill tissue. gill-associated amoebae trophozoites were positively selected by plastic adherence for culture in seawater, where they proliferated using heat-killed e. coli as a nutrient source. one isolate of gill-harvested amoebae designated np251002 was morphologically consistent to ... | 2005 | 16231639 |
| the effect of environmental factors on the distribution of neoparamoeba pemaquidensis in tasmania. | aquaculture in tasmania is mostly carried out in estuaries. these estuarine habitats show a great variety and form unique environments in which neoparamoeba pemaquidensis, the amoebic gill disease (agd)-causing protozoan, may or may not survive. tasmania is divided into two zones, one where agd is present and one where agd is absent, but any ecological data to rationalize this distribution is lacking. in in vitro trials n. pemaquidensis strains were exposed to different concentrations of ammoniu ... | 2005 | 16302952 |
| high yield and rapid growth of neoparamoeba pemaquidensis in co-culture with a rainbow trout gill-derived cell line rtgill-w1. | neoparamoeba pemaquidensis is an ubiquitous amphizoic marine protozoan and has been implicated as the causative agent for several diseases in marine organisms, most notably amoebic gill disease (agd) in atlantic salmon. despite several reports on the pathology of agd, relatively little is known about the protozoan and its relationship to host cells. in this study, an in vitro approach using monolayers of a rainbow trout gill cell line (rtgill-w1, atcc crl-2523) was used to rapidly grow large num ... | 2006 | 16911534 |
| neoparamoeba perurans n. sp., an agent of amoebic gill disease of atlantic salmon (salmo salar). | amoebic gill disease (agd) is a potentially fatal disease of some marine fish. two amphizoic amoebae neoparamoeba pemaquidensis and neoparamoeba branchiphila have been cultured from agd-affected fish, yet it is not known if one or both are aetiological agents. here, we pcr amplified the 18s rrna gene of non-cultured, gill-derived (ncgd) amoebae from agd-affected atlantic salmon (salmo salar) using n. pemaquidensis and n. branchiphila-specific oligonucleotides. variability in pcr amplification le ... | 2007 | 17561022 |
| characterization of neoparamoeba pemaquidensis strains: pcr-rflp of the internal transcribed spacer region from the amoeba and endosymbiont. | neoparamoeba pemaquidensis continues to be an ongoing problem for commercial finfish aquaculture and has also sporadically been associated with mass mortalities of commercially relevant marine invertebrates. despite the ubiquity and importance of this amphizoic amoeba, our understanding of the biology as it applies to host range, pathogenicity, tissue tropism, and geographic distribution is severely lacking. this may stem from the inability of current diagnostic tests based on morphology, immuno ... | 2007 | 17760387 |
| microheterogeneity and coevolution: an examination of rdna sequence characteristics in neoparamoeba pemaquidensis and its prokinetoplastid endosymbiont. | neoparamoeba pemaquidensis, the etiological agent of amoebic gill disease, has shown surprising sequence variability among different copies of the 18s ribosomal rna gene within an isolate. this intra-genomic microheterogeneity was confirmed and extended to an analysis of the internal transcribed spacer (its) region. high levels of intra-genomic nucleotide diversity (pi=0.0201-0.0313) were found among sequenced its regions from individual host amoeba isolates. in contrast, the its region of its e ... | 2007 | 17910686 |
| in vitro effect of garlic extract and metronidazole against neoparamoeba pemaquidensis, page 1987 and isolated amoebae from atlantic salmon. | neoparamoeba pemaquidensis believed to be the most prevalent parasite of atlantic salmon industry in australia. in the present study, the in vitro effects of crude extract of garlic and metronidazole were investigated using a primary culture toxicity assay. garlic extract appeared to be completely effective at killing a cultured strain (np251002) of neoparamoeba pemaquidensis in vitro at a dilution of 1:100 with in 24 h. the number of viable amoebae after using garlic extract in lower dilutions ... | 2008 | 18819591 |
| applications and potential uses of fish gill cell lines: examples with rtgill-w1. | gills are unique structures involved in respiration and osmoregulation in piscinids as well as in many aquatic invertebrates. the availability of the trout-derived gill cell line, rtgill-w1, is beginning to make impacts in fish health and toxicology. these cells are available from the american type culture collection as atcc crl 2523. the cells have an epithelioid morphology and form tight monolayer sheets that can be used for testing epithelial resistance. the cells can be grown in regular tiss ... | 2009 | 19184248 |
| genomic characterization of neoparamoeba pemaquidensis (amoebozoa) and its kinetoplastid endosymbiont. | we have performed a genomic characterization of a kinetoplastid protist living within the amoebozoan neoparamoeba pemaquidensis. the genome of this "ichthyobodo-related organism" was found to be unexpectedly large, with at least 11 chromosomes between 1.0 and 3.5 mbp and a total genome size of at least 25 mbp. | 2011 | 21666073 |
| heme pathway evolution in kinetoplastid protists. | kinetoplastea is a diverse protist lineage composed of several of the most successful parasites on earth, organisms whose metabolisms have coevolved with those of the organisms they infect. parasitic kinetoplastids have emerged from free-living, non-pathogenic ancestors on multiple occasions during the evolutionary history of the group. interestingly, in both parasitic and free-living kinetoplastids, the heme pathway-a core metabolic pathway in a wide range of organisms-is incomplete or entirely ... | 2016 | 27193376 |