Cysts In Skeletal Muscle Research Articles

The Dangerous Side of Being a Predator: Toxoplasma gondii and Neospora caninum in Birds of Prey.

Toxoplasma gondii and Neospora caninum are apicomplexan protozoa of major concern in livestock and T. gondii is also considered one of the major threats and a public health concern. These protozoa have a wide range of intermediate hosts, including birds. The present work aimed to assess the prevalence of these cyst-forming parasites in migratory and sedentary birds of prey. The skeletal muscle and myocardium of 159 birds of prey from Central Italy, belonging to 19 species and recovered across 6 Wildlife Recovery Centers/Care structures along the Italian migratory route, were collected specifically for molecular (PCR) and for histopathological analysis to detect T. gondii and N. caninum. For the molecular analysis, genomic DNA was extracted. The DNA was tested by sequence typing, targeting GRA6, 529 bp repeated element, B1, PK1, BTUB, SAG2, alt.SAG2, and APICO genes for T. gondii and to end-point PCR targeting NC5 gene for N. caninum. Thirty-seven out of the one hundred and fifty-nine analyzed samples tested positive for T. gondii with a prevalence of 23.27% and nine for N. caninum, with a prevalence of 5.66%. Thirty-two sequences were obtained from the thirty-seven isolates of T. gondii. Among these, 26 presented alleles compatible with type I strain in 1 or more loci, 4 with type II strain and 2 consisted of atypical strains. Toxoplasma gondii genetic variability in birds of prey confirms previous findings of wildlife as reservoirs of atypical strains. Results from the histology showed few protozoal tissue cysts in skeletal muscle (n. 4) and hearts (n. 2).

Kudoa sp. (Myxozoa, Multivalvulida): first report in five commercial fish species from the Canary Islands-FAO 34 (Macaronesia-Spain).

Kudoid myxozoans have been reported causing serious chronic problems in marine fisheries, by reducing the market value of infected fish through pathological damage to the host musculature. We report here the overall prevalence of a Kudoa species in 84/277 (30.3%) fishes from 20 different species of high commercial value captured between October 2011 and December 2013 from the United Nations Food and Agriculture Organization (FAO) 34 commercial fishing area, near the coast of the Canary Islands (Spain). Macroscopic examination showed myxozoan-like cysts in skeletal muscle from 5 of the 20 fish species examined, with the following prevalences: Pagellus acarne (86.7%), Pagellus erythrinus (46.5%), Serranus cabrilla (27.8%), Spondyliosoma cantharus (19.4%), and Sarpa salpa (28.6%). Infection intensity was determined based on spore counts following muscle tissue digestion. Morphometric studies to characterize the species and DNA sequence analysis results suggest that these infections are attributable to a Kudoa species closely related to Kudoa trachuri. This paper reports the first study on a multivalvulidan species to be identified from the Canary Islands. Furthermore, this is the first report of Kudoa parasites in all of the hosts mentioned above, with the exception of P. acarne.

SARCOCYSTOSIS OF WATER-FOWL IN THE TERRITORY OF THE KURGAN REGION

Wild duck meat is a popular dietary product, complete in amino acid composition, rich in vitamins of group B, macro- and micro-elements, essential fatty acids. When eaten, such meat should be safe for humans. Sarcocystosis is a zooanthroponotic disease. The causative agent in ducks is S. rileyi. The definitive hosts are domestic and wild carnivores, as well as humans. Intermediate hosts are herbivores, reptiles, mammals, rodents, omnivores. The contamination of birds with sarkosporidii can reach up to 70%. The pathogen is characterized by interspecific specificity. The diagnosis of sarcocystosisis is based on the results of dissection and microscopy. In the territory of the Kurgan Region, sarcocystosis was recorded in two drakes of the mallard and of the common shoveler female, by the detection of multiple muscle cysts in skeletal muscles as a result of the opening of the carcass. Extensiveness of invasion with sarcocystosis was 8% in 2016, 2.7% in 2017. Infected carcasses have an unpleasant, sour muscle odor. The muscles in the incision are sticky, flabby in texture, when pressed with a spatula with a slow recovery of the fossa. To eliminate the spread of helminthiasis, it is necessary to develop effective control and prevention measures against it. Meat of a wild bird without fail should pass Veterinary and Sanitary Expertise. In the case of sarcocystosis, it is prohibited to use such meat for human and domestic animals. Disposal of carcasses affected by sarkosporidia should imply that homeless and wild animals cannot access it. Sarcocytosis duck meat must be disposed of by burning or burying it in pits to a depth of at least 2 m.

A novel Sarcocystis-associated encephalitis and myositis in racing pigeons

Sarcosporidian cysts in the skeletal muscle of domestic pigeons (Columba livia f. domestica) have previously been attributed to infection with Sarcocystis falcatula, which is shed in the faeces of the opossum (Didelphis virginiana). Here, we describe fatal spontaneous encephalitis and myositis associated with Sarcocystis infections in three flocks of racing pigeons with 47 of 244 animals affected. The clinical course was characterized by depression, mild diarrhoea, torticollis, opisthotonus, paralysis and trembling. Histopathological examination of 13 pigeons revealed generalized severe granulomatous and necrotizing meningoencephalitis and myositis with sarcosporidian cysts. Light and transmission electron microscopy identified cysts in heart and skeletal muscle of 1 to 2 mm in length and 20 to 50 µm in width. These were subdivided into small chambers by fine septae and filled with lancet-shaped cystozoites (7.5×1.5 µm) and dividing metrocytes, which is characteristic for Sarcocystis. The cysts had smooth walls and were devoid of protrusions typical of S. falcatula. Polymerase chain reaction amplification and sequencing of the internal transcribed spacer region (ITS-1) and the complete 28S rRNA identified a novel Sarcocystis species with only 51% ITS-1 nucleotide sequence similarity with S. falcatula. A phylogenetic comparison of the 28S rRNA revealed close sequence homologies with Frenkelia microti, Frenkelia glareoli and Sarcocystis neurona. The clinical, histopathological, electron microscopic and genetic data are unlike any previously described protozoan infections in pigeons, suggesting a novel, severe disease due to an as yet undescribed Sarcocystis species.

Prevalence of Sarcocystis sp. in stranded Atlantic white-sided dolphins (Lagenorhynchus acutus).

In January 1998 and 1999, two mass strandings of dolphins occurred in Wellfleet, Massachusetts. The strandings were composed of 97 and 53 animals, respectively. Tissues from 35 Atlantic white-sided dolphins (Lagenorhynchus acutus) from the 1998 stranding and 52 from the 1999 stranding were examined histologically. In the 1998 stranding, unidentified protozoal tissue cysts were seen in skeletal muscle from 11 of 28 (39%) dolphins. In addition, two dolphins had a protozoal tissue cyst in cardiac muscle. In the 1999 stranding, nine of 23 (39%) dolphins had the same protozoal tissue cysts in skeletal muscle. The identification of these protozoal tissue cysts as Sarcocystis sp. was confirmed by light and transmission electron microscopy. The high prevalence of sarcocysts in these dolphins suggests that they are likely intermediate hosts for previously undescribed Sarcocystis spp. The ultrastructure of the sarcocyst walls suggests that more than one species of Sarcocystis are present in dolphins.

Immunohistochemical and ultrastructural evidence for Neospora caninum tissue cysts in skeletal muscles of naturally infected dogs and cattle

Protozoan stages were detected in the skeletal muscles of four dogs suffering from neosporosis and two neonatal calves with confirmed Neospora caninum- infection which could be immunohistochemically labelled by an antiserum against the bradyzoite-specific antigen BAG-5. In one calf, a tissue cyst was labelled by an antiserum against the N. caninum isolate NC-1. Ultrastructurally, a 0.3–1 μm-thick cyst wall surrounded the labelled parasites. The cysts were located within myofibres and contained varying numbers of bradyzoites each measuring 5.2(±0.6)×1.6(±0.3) μm. The encysted stages showed typical ultrastructural features of N. caninum bradyzoites with subterminal nuclei, electron-dense rhoptries, and micronemes that were orientated perpendicular to the zoite pellicle. Immunohistochemistry and serology did not reveal any evidence for co-infection with Toxoplasma gondii. The detection of tissue cysts in skeletal muscle of N. caninum-infected intermediate hosts is of major epidemiological importance for the understanding of how definitive or intermediate carnivorous hosts become infected with N. caninum.

Toxoplasmosis

Toxoplasma gondii is a unicellular protozoan. The definitive hosts, cats, produce hardy oocysts and sporozoites. Ingestion by a nonfeline leads to the formation of tachyzoites acutely, which cause parasitemia and further dissemination, and bradyzoites, which lead to latent infection with the formation of tissue cysts in skeletal muscle, heart muscle, and central nervous system (CNS) tissue. Toxoplasmosis can be transmitted to humans by ingestion of tissue cysts in raw or inadequately cooked infected meat or in uncooked foods that have come in contact with contaminated meat, by inadvertent ingestion of oocysts and sporozoites in cat feces, or transplacentally. Immunocompetent adults and adolescents with primary infection are generally asymptomatic, but symptoms may include mild malaise, lethargy, and lymphadenopathy. Specific treatment for nonpregnant adults and adolescents is not required. Immunosuppressed patients may experience more severe manifestations, including splenomegaly, chorioretinitis, pneumonitis, encephalitis, and multisystem organ failure. These patients are also prone to reactivation of latent infection involving the CNS. All patients with human immunodeficiency virus infection and CD4 counts <100 cells per cubic millimeter should be treated prophylactically with pyrimethamine-sulfonamide. Congenital toxoplasmosis is marked by the classic triad of chorioretinits, intracranial calcifications, and hydrocephalus. Current studies have determined that prolonged treatment (1–2 years) of neonates with fansidar is important to prevent serious sequelae. Diagnosis of acute toxoplasmosis is mainly by antibody detection and generally only undertaken in pregnant patients with risk factors for transplacental transmission. All positive screening tests in pregnant women must be confirmed at a toxoplasma reference laboratory. Recent studies have shown that polymerase chain reaction testing of amniotic fluid is useful for identification or exclusion of fetal T. gondii infection. Ultrasound can be used as an adjunct to serological screening but cannot itself definitively diagnose disease. Early–first-trimester maternal infections are less likely to result in congenital infection, but the sequelae are more severe. Transplacental passage is more common when maternal infection occurs in the latter half of pregnancy, but fetal injury is usually much less severe. Typically, infected pregnant patients are treated with pyrimethamine-sulfonamide for positive PCR–amniotic-fluid testing and with spiramycin for negative PCR-AF testing.

A Light Microscopic Comparison of The Cysts of Four Species of Sarcocystis Infecting The Domestic Reindeer (Rangifer Tarandus) in Northern Norway

Fresh preparations of micro-isolated sarcocysts from skeletal and cardiac muscle of 12 reindeer were examined by light microscopy. On the basis of cyst structure and cyst wall structure 4 Sarcocystis spp. could be differentiated. New names have been proposed for 2 previously unnamed Sarcocystis spp. of reindeer, and S. grueneri has been redefined. S. rangiferi n. sp. had macroscopic cysts in skeletal muscle measuring 2106×403 µm. The cyst wall protrusions were finger-like and measured 13.2×6.7 µm. The cysts were surrounded by a layer of fibrillar material. S. tarandi n. sp. had micro- to macroscopic cysts primarily in skeletal muscle, but a few cysts were found in the heart of one animal. In skeletal muscle the cysts measured 999×75µm; in the heart the cysts were shorter and wider. The cyst wall protrusions were fingerlike and measured 9.2×2.2 µm. S. grueneri had micro- to macroscopic cysts in cardiac muscle measuring 581×137 µm. The cyst wall was thin and relatively smooth with no visible protrusions. Sarcocystis sp. had micro- to macroscopic, slender cysts in skeletal muscle measuring 916×64 µm. The cyst wall had tightly packed, short, knob-like protrusions. The cysts of this species were previously classified as cysts of S. grueneri.

Sarcocystis SP. IN THE EASTERN COTTONTAIL (Sylvilagus floridanus)

Sarcocystis sp. was observed in 100 of 185 (54.1%) Eastern cottontails (Sylvilagus floridanus) examined in Pennsylvania over a three year period. Gross and histologic examination commonly revealed cysts in skeletal muscle of the fore and hind legs, flanks and loins. Two rabbits had cysts in esophageal skeletal muscle. Host response to Sarcocystis sp. is described. Adult rabbits had a significantly greater rate of infection (69.3%) than juveniles (20.7%) (P less than 0.01).

Recognition of cyclic transmission of Sarcocystis muris by cats.

Sarcocystis muris, obtained from laboratory and house mice, was transmitted experimentally to cats. When cysts in the skeletal muscle of mice were ingested by cats, bradyzoites developed directly into gametes in the intestinal mucosa of the cats. After five to 11 days, infectious sporulated sporocysts (8.5 x 10.3 mum) were shed by cats for up to three months. After ingestion of the sporocysts, S. muris multiplied first in the livers and then in the skeletal muscle of mice. Cysts in skeletal muscle attained a length of 5-6 mm and were visible to the naked eye. With heavy infections the cysts outlined major muscle groups. Lesions in mice were apparently the result of degeneration or rupture of cysts, with myositis and sometimes muscle necrosis, leading to locomotor impairment in heavy infection. S. muris required approximately 76 days of development in mice before becoming infectious for cats. S. muris is perpetuated by an obligatory two-host cycle (mouse-cat). Both cats and mice could be infected repeatedly. Rats, hamsters, and guinea pigs did not become infected.

Hammondia hammondi gen. nov., sp.nov., from domestic cats, a new coccidian related to Toxoplasma and Sarcocystis.

Hammondia hammondi gen.nov.,sp.nov (Eimeriorina:Sarcocystidae) is described as an obligate heteroxenous protozoon of domestic cats (final host) and laboratory mice (experimental intermediate host). Oocysts from the final host are infectious only for the intermediate host; and cysts from the intermediate host are infectious only for the final host. Intracellular cysts develop principally in striated muscle of mice that ingest oocysts, with a few cysts in the brain and perhaps elsewhere. Cysts are without septa or radial spines; bradyzoites are slender, there is no evidence of metrocytes. Cysts are not infectious for mice. After the ingestion of cysts by cats, a multiplicative cycle precedes the development of gametocytes in the epithelium of the samll intestine. Oocysts are shed unsporulated, sporogony is outside of the host, resulting in two sporocysts with four sporozoites each. Oocysts of the species average 11 x 13 mum. The prepatent period i 5s 5 to 8 days, and oocyst shedding persists for 10 to 28 days followed by immunity. Cysts in skeletal muscle measured between 100 and 340 mum in length and 40 and 95 mu-m in width. Experimental intermediate hosts are laboratory mice, rats, hamsters, guinea pigs, Peromyscus and Mastomys. Some of the intermediate hosts develop low levels of antibody and some cross-immunity against Toxoplasma; however, this has not been observed in cats.