ABSTRACT
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
Subject(s)
Cysts , Diagnosis, Differential , Opossums , Phylogeny , Microscopy, ElectronABSTRACT
Locality prepared crude F. hepatica adult antigen for ocular instillation was evaluated in live sheep and buffaloes compared to stool examination and macroscopic examination of these animal after being slaughtered. Ocular instillation proved to be cheap, simple, time consuming, but could not replace stool examination, due to false positive cross reactions