Fine Structure of an Unidentified Protozoon in the Epithelium of Rainbow Trout Exposed to Water with <i>Myxosoma cerebralis</i>*

Daniels, Stephen B.; Herman, Roger L.; Burke, C. N.

doi:10.1111/j.1550-7408.1976.tb03795.x

Cited by 20 publications

(13 citation statements)

References 2 publications

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“…The findings also relate to work described by Daniels et al (1976), who found similar forms in epihelia of fish exposed to undefined infective agents for whirling disease, but did not establish a relation to actual disease. In both that study and the present study fish were exposed to whirling disease infectivity.…”

Section: Discussionsupporting

confidence: 50%

Portals of entry for salmonid whirling disease in rainbow trout

Markiw¹

1989

Dis. Aquat. Org.

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Portals of entry via the skln, fins, buccal cavlty and dlgestlve tract have been demonstrated for the myxozoan that causes salmonld whirling disease Exper~mentally, young rainbow trout Salmo ga~rdner~ were evposed to tnactlnomyxon spores W~thin 10 nun after ~nitial exposure intracellular aggregates of trlactinomyxon sporoplasms appeared in the e p~t h e h a of exposed fish Dunng several hours following penetrat~on, the sporoplasms moved or were trdnsported from the external ep~thelial layers into deeper strata Unexposed control trout were free of the organlsm The aggregates of intracellular triactinomyxon sporoplasms were idenufied serologically as belng Myxobolus cerebrahs

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Section: Discussionsupporting

confidence: 50%

Portals of entry for salmonid whirling disease in rainbow trout

Markiw¹

1989

Dis. Aquat. Org.

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“…These cells then undergo an endogenous cleavage producing an inner secondary cell within an enveloping primary cell. Secondary cells then proliferate through rapid, synchronous mitosis, and the host cell nucleus is compressed between the large parasitic aggregate and the host cell plasmalemma (Daniels et al 1976; El‐Matbouli et al 1995). The secondary cells then undergo endogenous divisions to produce new cell‐doublets with an enveloping cell and inner cell.…”

Section: Life Cycles and Developmentmentioning

confidence: 99%

Recent Advances in Our Knowledge of the Myxozoa

Kent

Andrée

Bartholomew

et al. 2001

J Eukaryotic Microbiology

551

377

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In the last few years two factors have helped to significantly advance our understanding of the Myxozoa. First, the phenomenal increase in fin fish aquaculture in the 1990s has lead to the increased importance of these parasites; in turn this has lead to intensified research efforts, which have increased knowledge of the development, diagnosis. and pathogenesis of myxozoans. The hallmark discovery in the 1980s that the life cycle of Myxobolus cerebralis requires development of an actinosporean stage in the oligochaete. Tubifex tubifex, led to the elucidation of the life cycles of several other myxozoans. Also, the life cycle and taxonomy of the enigmatic PKX myxozoan has been resolved: it is the alternate stage of the unusual myxozoan, Tetracapsula bryosalmonae, from bryozoans. The 18S rDNA gene of many species has been sequenced, and here we add 22 new sequences to the data set. Phylogenetic analyses using all these sequences indicate that: 1) the Myxozoa are closely related to Cnidaria (also supported by morphological data); 2) marine taxa at the genus level branch separately from genera that usually infect freshwater fishes; 3) taxa cluster more by development and tissue location than by spore morphology; 4) the tetracapsulids branched off early in myxozoan evolution, perhaps reflected by their having bryozoan, rather than annelid hosts; 5) the morphology of actinosporeans offers little information for determining their myxosporean counterparts (assuming that they exist); and 6) the marine actinosporeans from Australia appear to form a clade within the platysporinid myxosporeans. Ribosomal DNA sequences have also enabled development of diagnostic tests for myxozoans. PCR and in situ hybridisation tests based on rDNA sequences have been developed for Myxobolus cerebralis, Ceratomyxa shasta, Kudoa spp., and Tetracapsula bryosalmonae (PKX). Lectin-based and antibody tests have also been developed for certain myxozoans, such as PKX and C. shasta. We also review important diseases caused by myxozoans, which are emerging or re-emerging. Epizootics of whirling disease in wild rainbow trout (Oncorhynchus mykiss) have recently been reported throughout the Rocky Mountain states of the USA. With a dramatic increase in aquaculture of fishes using marine netpens, several marine myxozoans have been recognized or elevated in status as pathological agents. Kudoa thyrsites infections have caused severe post-harvest myoliquefaction in pen-reared Atlantic salmon (Salmo salar), and Ceratomyxa spp., Sphaerospora spp., and Myxidium leei cause disease in pen-reared sea bass (Dicentrarchus labrax) and sea bream species (family Sparidae) in Mediterranean countries.

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“…However, the articles on the portals of entry of myxosporeans to fish are limited only to research on Myxobolus cerebralis (Daniels et al 1976, Markiw 1989. It has been suggested that M. cerebralis penetrated through the skin and/or gills of fish as evidenced by the presence of development stages in the skin, fins, buccal cavity and digestive tract of fish exposed to the infective stage.…”

Section: Introductionmentioning

confidence: 99%

Chemoresponse of actinosporean spores of Myxobolus cultus to skin mucus of goldfish Carassius auratus

Yokoyama¹,

Ogawa²,

Wakabayashi³

1995

Dis. Aquat. Org.

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Chemoresponse of actinosporean spores of Myxobolus cultus to goldfish mucus was studied and determination of the reactants was attempted. Reactiv~ty was counted as the percentage of empty actinosporean spores after mixing with the mucus The activity of mucus was lnaintained at -80°C but was n~ostly lost within 1 d at 5°C Heating at 30 to 80°C for 30 min did not affect the activity While neutral pH favored the reaction, strong a c~d and alkali decreased the reaction Phosphate buffer saline and sodlum chlonde solutions w t h inolanty >O 05 M inhibited the reaction A shnnkage of sporoplasms Inside the eplspore cavity caused by the high osmotic pressure was obseived Punficatlon of the reactants from goldfish mucus by gel filtration and ultrafiltrat~on revealed that they were lo~v-molecular-weight substances (c6000 h4W) Additionally, fish mucus from other flsh species (such as common carp Cyprinus carpio loach ~Misguinus angulll~cal~datus, r a~n b o w t~o u t Oncorhynchus mykiss, catfish Parasilurus asotus, and Japanese eel Anguilla japonica), as lvell as mucin from bovine submaxillary gland were slm~larly actlve It is suggested that actlnosporean spores I ecognlze fish hosts ~l t h low-molecular-xveight mucin components in skln mucus and that the portal of entry 1s the outer surface of flsh KEY WORDS: Myxosporean .

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Fine Structure of an Unidentified Protozoon in the Epithelium of Rainbow Trout Exposed to Water with *Myxosoma cerebralis**

Cited by 20 publications

References 2 publications

Portals of entry for salmonid whirling disease in rainbow trout

Portals of entry for salmonid whirling disease in rainbow trout

Recent Advances in Our Knowledge of the Myxozoa

Chemoresponse of actinosporean spores of Myxobolus cultus to skin mucus of goldfish Carassius auratus

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Fine Structure of an Unidentified Protozoon in the Epithelium of Rainbow Trout Exposed to Water with Myxosoma cerebralis*

Cited by 20 publications

References 2 publications

Portals of entry for salmonid whirling disease in rainbow trout

Portals of entry for salmonid whirling disease in rainbow trout

Recent Advances in Our Knowledge of the Myxozoa

Chemoresponse of actinosporean spores of Myxobolus cultus to skin mucus of goldfish Carassius auratus

Contact Info

Product

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Fine Structure of an Unidentified Protozoon in the Epithelium of Rainbow Trout Exposed to Water with *Myxosoma cerebralis**