Observations on the occurrence of Spraguea lophii in Mediterranean lophiids.

In the Mediterranean Sea, anglerfish Lophius budegassa and Lophius piscatorius support an important fishery, and landings have increased in recent years. These species are infected by the microsporean Spraguea lophii, a parasite that infects their nervous system giving rise to multiple cysts. Due to the high value of these fish and conspicuous nature of the infection, we determined the apparent prevalence of this parasite in both Lophius spp. Specimens were obtained from commercial catches along the NW Mediterranean Sea during 2013. The parasite was observed in the nerves from the peripheral nervous system of the individuals and was detected at the prevalence of 69.2% (202/292) and 100% (58/58) in L. budegassa and L. piscatorius, respectively. Non-significant differences were noted between sexes of L. budegassa (χ(2) = 0.683; p = 0.409), although a positive correlation was noted between host size and prevalence (χ(2) = 6.134; p = 0.013). During the sampling, two specimens of L. budegassa with atypical morphological characteristics, pigment anomalies and blindness and infected with S. lophii xenomas were described.

Efficacy of the fumagillin analog TNP-470 for Nucleospora salmonis and Loma salmonae infections in chinook salmon Oncorhynchus tshawytscha.

Oral treatment with fumagillin is effective for controlling various microsporean and myxosporean infections in fish. We tested a synthetic analog of fumagillin, TNP-470 (Takeda Chemical Industries), for its efficacy against 2 microsporean pathogens of salmon: Loma salmonae and Nucleospora salmonis. Chinook salmon Oncorhynchus tshawytscha were experimentally infected with either L. salmonae (per os) or N. salmonis (intraperitoneal, i.p., injection) and held in fresh water at 15 degrees C. Fish were then divided into 3 replicate groups: untreated or treated orally at 1.0 mg or at 0.1 mg drug kg-1 fish d-1. With L. salmonae, the high dose fish had 0.32 xenomas mm-2 of gill tissue compared to controls at 24.5 xenomas per mm2. With N. salmonis infections, untreated fish exhibited 100% infection, showed prominent clinical signs (e.g. renal swelling, anaemia), and high mortality. In contrast, fish treated at 1.0 mg kg-1 showed no clinical signs, and 16% of those treated at 0.1 mg kg-1 showed only mild gross pathological changes. With the treated groups, over 50% of the fish exhibited extremely light infections, even with high dose treatments, but no mortalities were attributed to N. salmonis infections. Uninfected fish treated at 1.0 mg drug kg-1 fish d-1 for 5 wk appeared clinically normal and showed no reduction in growth. However, about half of these fish exhibited atrophy of the renal interstitial hematopoietic tissue.

A 3-year follow-up of a brazilian AIDS patient with protracted diarrhea caused by Enterocytozoon bieneusi

Enterocytozoon bieneusi e o mais comum microsporidio agente de infeccoes gastrointestinais que ocorre predominantemente em pessoas com AIDS. Em todo o mundo os microsporidios sao reconhecidos como importantes patogenos oportunistas, entretanto poucos casos ja foram diagnosticados no Brasil, provavelmente devido ao pouco conhecimento do quadro clinico que os agentes produzem ou a dificuldades no diagnostico laboratorial. No presente trabalho relatamos o caso de um paciente brasileiro HIV-positivo acompanhado durante 3 anos, em que foram detectados esporos de microsporidios nas fezes, identificados como Enterocytozoon bieneusi por microscopia eletronica e PCR. O paciente apresentava diarreia cronica, contagem de linfocitos CD4 abaixo de 100/mm3 e fez uso de albendazol em diferentes ocasioes com melhora transitoria da diarreia, que reaparecia logo que a droga era suspensa...

Occurrence of Loma cf. salmonae in brook, brown and rainbow trout from Buford trout hatchery, Georgia, USA.

During a 6 mo study of moribund trout from Buford hatchery, Buford, Georgia, USA, a Loma cf. salmonae microsporidian parasite was studied in the gills of brook trout Salvelinus fontinalis, brown trout Salmo trutta, and rainbow trout Oncorhynchus mykiss. This parasite was morphologically similar to L. salmonae and L. fontinalis but differed in spore size. Scanning and transmission electron microscopy demonstrated that xenomas were embedded in gill filaments. Transmission electron micrographs prepared from fresh tissue showed mature spores with 12 to 15 turns of their polar tube. Spore diameters for the Georgia strain from formalin-fixed gill tissues measured 3.5 (SD +/- 0.1) by 1.8 (SD +/- 0.1) microns. Electron micrographs of formalin-fixed, deparaffinized tissues of rainbow trout from Pennsylvania and West Virginia show spores with a diameter of 3.5 (+/- 0.2) by 1.7 (+/- 0.1) microns and 3.4 (+/- 0.2) by 1.8 (+/- 0.1) microns, respectively. Transmission electron micrographs of spores from Pennsylvania and West Virginia show that mature spores from both states had 13 to 15 turns of their polar tubes. Measurements from transmission electron micrographs prepared from alcohol-fixed tissues from Virginia fish contained spores with a diameter of 3.0 (+/- 0.3) by 1.1 (+/- 0.3) microns and 12 to 15 turns of their polar tubes. These measurements are consistent with L. salmonae and therefore suggest that the parasite is present on the east coast of the United States. During the height of the Georgia epizootic, the percentage of fish with observed xenomas reached 62.2% (N = 87), and the highest number of xenomas counted per 10 gill filaments was 133 (N = 87). The microsporidian epizootic occurred either during the autumn months or when intake river water quality reached combined iron-manganese concentrations as high as 1.01 (mean 0.44, SD +/- 0.42) mg-1.

Plasmacytoid leukemia of chinook salmon.

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.

Transmission of Loma salmonae (Microsporea) to chinook salmon in sea water.

Transmission studies were conducted to determine if Loma salmonae was transmissible in sea water. Transmission of L. salmonae to chinook salmon (Oncorhynchus tshawytscha) held in sea water was achieved by exposing fish to macerated, infected gill tissue. Fish were exposed in seawater in a flow-through aquarium, and the infection was detected as soon as 5 wk after exposure. Heavily infected fish exhibited numerous xenomas in the branchial arteries, central venous sinusoids, and within the blood channels of the lamellae. The pathological changes were similar to those seen in pen-reared salmon with L. salmonae infections. The infection was not observed in Atlantic salmon (Salmo salar), Pacific herring (Clupea pallasi, family Clupeidae), or shiner perch (Cymatogaster aggregata, family Embiotocidae), experimentally exposed using identical methods. This study suggests that L. salmonae is transmissible to chinook salmon in seawater netpens. Fish farmers and fish health specialists should consider this possibility when developing and implementing strategies to control the infection.

Localization of infection by the microsporidian Enterocytozoon bieneusi in the gastrointestinal tract of AIDS patients with diarrhea.

OBJECTIVE: We compared the level of Enterocytozoon bieneusi infection at different sites within the small intestine among patients with AIDS. DESIGN: The level of E. bieneusi infection of each patient biopsy was determined and compared using semi-thin plastic section light microscopy and transmission electron microscopy (TEM). PATIENTS, PARTICIPANTS: Nine subjects with chronic diarrhea who had endoscopic biopsies of either proximal (bulb) or distal (fourth portion) duodenum plus proximal jejunum (just past ligament of Treitz), either simultaneously or within a few months of each other were studied. All patients had TEM-confirmed diagnoses of E. bieneusi intestinal microsporidiosis. RESULTS: The intensity of infection was always greater in biopsies taken from the patients' jejunum compared with those taken from the duodenal bulb. In one patient, the duodenal bulb biopsy was negative while the jejunal biopsy, taken at the same time, was positive. The distal duodenum was usually, but not always, equal to the jejunum in terms of parasite burden. Esophageal, gastric, and colorectal biopsies from these and other patients were negative for E. bieneusi. CONCLUSIONS: For the diagnosis of E. bieneusi to evaluate chronic diarrhea in AIDS patients, upper intestinal endoscopy biopsies should be taken at the most distal site possible.