''Spironucleus salmonicida'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

. It is a

flagellate A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and the ...

adapted to micro-aerobic environments that causes systemic infections in

salmonid Salmonidae (, ) is a family of ray-finned fish, the only extant member of the suborder Salmonoidei, consisting of 11 extant genera and over 200 species collectively known as "salmonids" or "salmonoids". The family includes salmon (both Atlantic a ...

fish. The species creates foul-smelling,

pus Pus is an exudate, typically white-yellow, yellow, or yellow-brown, formed at the site of inflammation during infections, regardless of cause. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collect ...

-filled

abscesses An abscess is a collection of pus that has built up within the tissue of the body, usually caused by bacterial infection. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pres ...

muscles Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

and

internal organs In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to a ...

of aquarium fish. In the late 1980s when the disease was first reported, it was believed to be caused by ''

Spironucleus barkhanus ''Spironucleus'' is a diplomonad genus that is bilaterally symmetrical and can be found in various animal hosts. This genus is a binucleate flagellate, which is able to live in the anaerobic conditions of animal intestinal tracts. A characteristi ...

''. Anders Jørgensen was the person that found out what species really caused the disease. There is a distinct lack of

models A model is an informative representation of an object, person, or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin , . Models can be divided int ...

for diverse microbial eukaryotes. ''Spironucleus salmonicida'' was chosen as a model due to its complex genome and ability to adapt to fluctuating environments. This ability was proven by genetically modifying the pathogen and seeing the results. By comparing these results with the closest model organism, ''

Giardia intestinalis ''Giardia duodenalis'', also known as ''Giardia intestinalis'' and ''Giardia lamblia'', is a flagellated parasitic protozoan microorganism of the genus ''Giardia'' that colonizes the small intestine, causing a diarrheal condition known as giard ...

'', researchers were able to see that the parasite has a more complex gene regulation system. This system of genetic modification was also used to sequence the genome for further study. ''Spironucleus salmonicida'' contains mitochondrion-related organelles (MROs). MROS identified in ''S. salmonicida'' contained similar protein import and Fe-S machinery as in ''

Giardia ''Giardia'' ( or ) is a genus of anaerobic flagellated protozoan parasites of the phylum Metamonada that colonise and reproduce in the small intestines of several vertebrates, causing the disease giardiasis. Their life cycle alternates be ...

'' mitosomes and the MROS contained enzyme characteristics similar to

hydrogenosome A hydrogenosome is a membrane-enclosed organelle found in some Anaerobic organism, anaerobic Ciliate, ciliates, Flagellate, flagellates, Fungus, fungi, and three species of Loricifera, loriciferans. Hydrogenosomes are highly variable organelles t ...

s, thereby affirming that hydrogen production is prevalent in the genus ''Spironucleus''. Hydrogenosomes produce ATP by substrate-level phosphorylation with hydrogen as a byproduct.

References

External links

Science Daily
{{Taxonbar, from=Q7578190 Fish diseases Metamonads Protists described in 2006 Metamonad species

References

Further reading

External links