Studies on Besnoitiosis bennetti in miniature donkeys

Besnoitia tissue cysts associated with the skin lesions recovered from the naturally-infected miniature donkeys [Equus asinus] during clinical examination were studied by the light and electron microscopy, as well as histochemically to elucidate the specific morphologic features of the cyst causing this disease. The cyst was differentiated phenotypically from those of other Besnoitia spp. The interpretation of results showed that morphometric attributes of the tissue cysts and the associated pathological changes in these donkeys were due to B. bennetti infection. The findings were confirmed by the phylogenetic analysis based on DNA sequences of the first internal transcribed spacer of nuclear rDNA. The cluster analysis showed that B. bennetti was distinct from all other Besnoitia spp. and positioned B. bennetti with parasites described from Besnoitia besnoiti of cattle and B. tarandi of reindeer. The genetic attributes complemented the morphological criteria and verified the accurate delimitation of the Besnoitia cysts isolated from these donkeys

Observations on besnoitiosis in virginia opossum [didelphis virginiana] from Michigan, USA

Besnoitia tissue cysts were found in five naturally-infected adult opossums [Didelphis virginiana] from Michigan. Details of the microscopy, histopathology, ultra-structure, and genetic features of the cysts were studied to identify their species-specific traits. The materials were differentiated phenotypically from cysts of other Besnoitia spp. by difference in size, pattern of tissue distribution, morphology of pellicle and nucleus, number of micronemes and rhoptries, amount of lipids and amylopectin, and presence of enigmatic bodies. Morphometric variations identified the tissue cysts and the pathologic changes in opossums host to be due to B. darlingi. The data were proved by phylogenetic analysis based on DNA sequences of the first internal transcribed spacer of nuclear rDNA. Cluster analysis showed that B. darlingi was distinct from all other Besnoitia spp. as two distinct phylogenetic clades: I- included Besnoitia spp. described from opossum [B. darlingi], sheep [B. jellisonf], rodent [B. akadoni] and rabbit [B. oryctofelisi] and clade II- encompassed parasites described from cattle [B. besnoiti], equids [B. bennetti] and reindeer [B. tarandi]. The genetic attributed particular to the genus Besnoitia complemented the morphological features and lead to accurate delimitation of Besnoitia species

Ultrastructure characteristics of Besnoitia darlingi tachyzoites brumpt, 1913 [protozoa: sarcocystidae] of the Michigan strain MIBD1

Tachyzoites of Besnoitia darlingi Brumpt, 1913 were redescribed based on new materials isolated from Virginia opossums [Dideiphis virginiana, Kerr] from Michigan, USA. Tachyzoites of the MIBD1 strain were propagated in bovine turbinate cell culture for more than two years. A comparison with previously described tachyzoites of the B. darlingi OP1 strain from Mississippi, USA revealed some morphological differences despite the remarkable genetic homogeneity between the two B. darlingi strains. MIBD1 tachyzoites were distinguished from OP1 tachyzoites by having more rhoptries, and fewer and haphazardly distributed micronemes at the conoidal end. This morphological heterogeneity between tachyzoites of the two strains suggests the role of geographical isolation in the Michigan strain. New morphological features of B. darlingi tachyzoites were described

Molecular and microscopic techniques for detection of Sarcocystis neurona sporocysts in fecal samples

Diagnosis of Sarcocystis sp. in the definitive host is generally by microscopic detection of the sporocysts in feces. This method is insensitive and cannot differentiate between species because sporocysts lack specific staining criteria. The hypothesis suggested that molecular techniques provide better alternatives to classical detection of Sarcocystis sporocysts. The sensitivity of two PCR assays was compared to one another and to microscopic examination by conventional fecal flotation and Diamant-Fuchsin staining procedures for detection of sporocysts spiked into mice feces. PCR1 assay using LSM1 and LSM2 primers that amplified 496 bp of the ssurRNA gene was more sensitive than the PCR2 method using JNB25 and JD396 primers that amplified 334 bp of a RAPD-derived marker. PCR1 gave positive results with 200 micro1 of fecal suspension spiked with as little as 5 sporocysts compared to 75 sporocysts detected by JNB25 and JD396 primers. PCR1 was more sensitive than conventional microscopy. PCR1 or PCR2 followed by sequencing or RFLP analysis not only detected Sarcocystis sporocysts in feces but also enabled to ascertain the genotype of the species as S. neurona

Sarcocystosis of sarcocystis felis in cats

The features of S. felis sarcocystosis in muscles of the domestic cats [Felis domesticus] were studied. A complete clinical history, post mortem, and histopathologic examinations were done for each cat. Multiple protozoan elliptical cysts were in the skeletal muscles, heart, and diaphragm muscles of 3/17 [17.6%] adult cats. Ultrastructural characteristics of the brady-zoites and cyst wall were consistent with those descried for S. felis in bobcat and domestic cat. Clinicopathological study in 3 cats showed hypertrophy cardiomyopathy and lymphosarcoma associated with S. felis. Tissue samples showed a spectrum of pathological changes such as multi-focal subacute myocarditis and multi-focal subarachnoid lymphocytic infiltration. DNA extracted from muscles diaphragm with cysts was tested by PCR and sequence analyses of ssurRNA gene. The phylogenetic reconstructions using neighbor-joining method showed that S. felis is closely related to S. neurona. The results were illustrated and photographed and peer discussed.