Nosema apis is a microsporidian, a small, unicellular parasite recently reclassified as a fungus that mainly affects honey bees. It causes nosemosis, also called nosema, which is the most common and widespread of adult honey bee diseases. The dormant stage of N. apis is a long-lived spore which is resistant to temperature extremes and dehydration, and cannot be killed by freezing the contaminated comb. Nosemosis is a listed disease with the Office International des Epizooties (OIE).
Microsporidia are a group of spore-forming unicellular parasites. These spores contain an extrusion apparatus that has a coiled polar tube ending in an anchoring disc at the apical part of the spore. They were once considered protozoans or protists, but are now known to be fungi, or a sister group to fungi. These fungal microbes are obligate eukaryotic parasites that use a unique mechanism to infect host cells. They have recently been discovered in a 2017 Cornell study to infect Coleoptera on a large scale. So far, about 1500 of the probably more than one million species are named. Microsporidia are restricted to animal hosts, and all major groups of animals host microsporidia. Most infect insects, but they are also responsible for common diseases of crustaceans and fish. The named species of microsporidia usually infect one host species or a group of closely related taxa. Approximately 10 percent of the species are parasites of vertebrates —several species, most of which are opportunistic, can infect humans, in whom they can cause microsporidiosis.
Microsporidiosis is an opportunistic intestinal infection that causes diarrhea and wasting in immunocompromised individuals. It results from different species of microsporidia, a group of microbial (unicellular) fungi.
A xenoma is a growth caused by various protists and fungi, most notably microsporidia. It can occur on numerous organisms; however is predominantly found on fish.
Enterocytozoon bieneusi is a species of the order Chytridiopsida which infects the intestinal epithelial cells. It is an obligate intracellular parasite.
The gilt-head bream, also known as the gilthead, gilt-head seabream or silver seabream, is a species of marine ray-finned fish belonging to the family Sparidae, the seabreams or porgies. This fish is found in the Eastern Atlantic and the Mediterranean. It is a highly esteemed food fish and an important species in aquaculture.
Glugea is a genus of microsporidian parasites, predominantly infecting fish. Infections of Glugea cause xenoma formation.
Encephalitozoon intestinalis is a parasite. It can cause microsporidiosis.
Paramoeba is a genus of common parasites, including species that can cause infection in fish, crabs, sea urchins and others.
Like humans and other animals, fish suffer from diseases and parasites. Fish defences against disease are specific and non-specific. Non-specific defences include skin and scales, as well as the mucus layer secreted by the epidermis that traps microorganisms and inhibits their growth. If pathogens breach these defences, fish can develop inflammatory responses that increase the flow of blood to infected areas and deliver white blood cells that attempt to destroy the pathogens.
The Warthin–Starry stain (WS) is a silver nitrate-based staining method used in histology. It was first introduced in 1920 by American pathologists Aldred Scott Warthin (1866–1931) and Allen Chronister Starry (1890–1973), for the detection of spirochetes. It has been considered a standard stain for the detection of spirochetes, and is also used to stain Helicobacter pylori, Lawsonia intracellularis, Microsporidia, and particulates. It is also important for confirmation of Bartonella henselae, a causative organism in cat-scratch disease.
Ceratomyxa is a genus of myxozoan.
Encephalitozoon cuniculi is a microsporidial parasite of mammals with world-wide distribution. An important cause of neurologic and renal disease in rabbits, E. cuniculi can also cause disease in immunocompromised people.
Nosema bombi is a microsporidian, a small, unicellular parasite recently reclassified as a fungus that mainly affects bumble bees. It was reclassified as Vairimorpha bombi in 2020. The parasite infects numerous Bombus spp. at variable rates, and has been found to have a range of deleterious effects on its hosts.
Sparicotyle chrysophrii is a species of monogenean, parasitic on the gills of the marine fish. It belongs to the family Microcotylidae. Its type-host is the gilt-head seabream.
Enteromyxum leei is a species of myxozoan, histozoic parasite that infects the intestinal tract and sometimes associated organs, like gall bladder and liver, of several teleostean fish species. Myxozoans are microscopic metazoans, with an obligate parasitic life-style. The parasite stages of this species live in the paracelullar space between fish enterocytes. It is the causative agent of enteromyxosis, or emaciative disease, also known as "razor blade syndrome" in sparid fish. E. leei has a wide host and geographical range within marine fish, and even freshwater fish have been infected experimentally. E. leei initially emerged in the Mediterranean in the late 1980s and it is believed to have been unintentionally introduced into the Red Sea. Its pathogenicity and economic impact depend on the host species. In the gilt-head seabream, it is manifested as a chronic disease that provokes anorexia, delayed growth with weight loss, cachexia, reduced marketability and increased mortality. In other species, it has no clinical signs. In sharpsnout seabream, infection results in very high mortality rates, which have pushed fish farmers to abandon the culture of this fish species.
Enteromyxum scophthalmi is a species of parasitic myxozoan, a pathogen of fish. It is an intestinal parasite of the turbot and can cause outbreaks of disease in farmed fish. It causes a cachectic syndrome characterised by loss of weight, muscle atrophy, weakness and fatigue.
Ceratothoa oestroides is a crustacean isopod, obligate ectoparasite of marine fish that dwells in the buccal cavity. It is the causative agent of various pathologies including tissue damage at the parasitisation site (tongue), growth defects, decrease in mean host weight and size and increases mortalities in farmed and wild fish populations. It has been recorded in six different fish families: Sparidae, Carangidae, Clupeidae, Maenidae, Scorpenidae, and Mugilidae.
Enterospora is a genus of protists belonging to the family Enterocytozoonidae.
Carlos José Correia de Azevedo is a Portuguese biologist specialising in microparasites of aquatic organisms, particularly Apicomplexa, Haplosporidia, Microsporidia, and Myxozoa.
