RESUMO
A novel microsporidium was observed in wild swamp guppies Micropoecilia picta from Levera Pond within Levera National Park Grenada, West Indies. Initial observations indicated similarity with Pseudoloma neurophilia, an important pathogen in zebrafish Danio rerio. P. neurophilia exhibit broad host specifity, including members of the family Poecillidae, and both parasites infect the central nervous system. However, spore morphology and molecular phylogeny based on rDNA showed that the swamp guppy microsporidium (SGM) is distinct from P. neurophilia and related microsporidia (Microsporidium cerebralis and M. luceopercae). Spores of the SGM were smaller than others in the clade (3.6 µm long). Differences were also noted in histology; the SGM formed large aggregates of spores within neural tissues along with a high incidence of numerous smaller aggregates and single spores within the surface tissue along the ventricular spaces that extended submeninx, whereas P. neurophilia and M. cerebralis infect deep into the neuropile and cause associated lesions. Analysis of small subunit ribosomal DNA sequences showed that the SGM was <93% similar to these related microsporidia. Nevertheless, one of 2 commonly used PCR tests for P. neurophilia cross reacted with tissues infected with SGM. These data suggest that there could be other related microsporidia capable of infecting zebrafish and other laboratory fishes that are not being detected by these highly specific assays. Consequently, exclusive use of these PCR tests may not accurately diagnose other related microsporidia infecting animals in laboratory and ornamental fish facilities.
Assuntos
Doenças dos Peixes , Microsporídios , Microsporidiose , Filogenia , Poecilia , Animais , Doenças dos Peixes/microbiologia , Doenças dos Peixes/parasitologia , Microsporídios/genética , Microsporídios/isolamento & purificação , Microsporídios/classificação , Microsporidiose/veterinária , Microsporidiose/microbiologia , Granada/epidemiologiaRESUMO
Pseudocapillaria tomentosa is a common pathogen of zebrafish (Danio rerio) in research facilities. We developed a method to collect and concentrate the nematode eggs using a modified sugar centrifugation method and documented their normal development. Embryonating stages with blastomere formation followed by elongation of the embryo prior to larva formation cumulated in developed larvae inside the eggs and hatching after 5-10 day. We then evaluated the efficacy of heat and chlorine to kill them based on a larva development assay. Eggs were exposed to 40, 50, 60 °C for 30 min and 1 h. Chlorine treatment was performed at 100, 250, 500, 1000, 3000 and 6000 ppm for 10 min. Samples exposed to 40 °C for 30 min or 1 h showed incidences of larvated eggs similar to controls. In contrast, no larvation occurred with eggs exposed to either 50 or 60 °C for 30 min or 1 h. Remarkably, in repeated assays, samples exposed to low doses of chlorine (100, 250, 500 and 1000 ppm for 10 min) showed significantly higher incidence of larvation than controls. Eggs treated with 3000 ppm for 10 min did not develop larvae, and no eggs were found after 6000 ppm treatment.
Assuntos
Antinematódeos/farmacologia , Aquicultura/métodos , Infecções por Enoplida/veterinária , Doenças dos Peixes/prevenção & controle , Trichuroidea/efeitos dos fármacos , Peixe-Zebra , Animais , Cloro/farmacologia , Relação Dose-Resposta a Droga , Infecções por Enoplida/parasitologia , Infecções por Enoplida/prevenção & controle , Doenças dos Peixes/parasitologia , Temperatura Alta , Óvulo/efeitos dos fármacos , Trichuroidea/embriologiaRESUMO
Plasmacytoid leukemia is a common disease of seawater pen-reared chinook salmon (Oncorhynchus tshawytscha) in British Columbia, Canada, but has also been detected in wild salmon, in freshwater-reared salmon in United States, and in salmon from netpens in Chile. The disease can be transmitted under laboratory conditions, and is associated with a retrovirus, the salmon leukemia virus. However, the proliferating plasmablasts are often infected with the microsporean Enterocytozoon salmonis, which may be an important co-factor in the disease.
Assuntos
Doenças dos Peixes , Leucemia Plasmocitária/veterinária , Microsporea/isolamento & purificação , Retroviridae/isolamento & purificação , Animais , Animais Domésticos , Animais Selvagens , Colúmbia Britânica , Chile , Rim/parasitologia , Rim/virologia , Leucemia Plasmocitária/parasitologia , Leucemia Plasmocitária/virologia , Salmão , Baço/parasitologia , Baço/virologia , Estados UnidosRESUMO
Two new species of Myxozoa from the brain of the green knife fish Eigemannia virescens are described: Myxobolus inaequus sp. n. has an unusually large spore body and extremely unequal polar capsules, and Henneguya theca sp. n. has an attenuated spore encased in a sheath not previously described in other Myxozoa . Only spores of the two species were observed, and infections caused no obvious pathological changes in the brain.