Sarcocystis infection in cattle at Assiut abattoir : Microscopical and serological studies

Abstract EN

The present work was conducted to study Sarcocystis infection in cattle by microscopically and serological examinations.

Samples from the ocular muscle, esophagus, diaphragm and heart of 100 cattle slaughtered at Assiut abattoir were examined grossly and microscopically.

The total infection rate of the examined cattle was found to be 94 %.

The infection rate in different organs was 89 % in ocular muscles, 84 % in esophageal muscles, 51 % in cardiac muscles and 30 % in diaphragm.

Serological examination of sera of the same examined animals by enzyme linked immuno-sorbent assay (ELIZA) revealed that the infection rate was 98 %.

The maximum antibody level of the examined cattle by ELIZA was associated with highly infected esophageal muscle with Sarcocystis cysts.

Two types of cysts were detected in the present work : microscopic thin-walled and macroscopic thick-walled cysts.

Microscopic thin-walled cysts were recovered in all positive animals.

Their cyst wall was narrow and homogenous.

The accurate identification of microscopic cysts as Sarcocystis cruzi has been completed after the success of experimental infection in puppies.

They began to shed sporocysts after seven days from infection and remained till the end of the experiment.

Macroscopic thick-walled cysts were recovered in four cases only.

Their cyst wall was composed of long striated protrusions in a palisade-like arrangement It could not be identified as Sarcocystis hirsuta or Sarcocystis hominis by light microscope, where differentiation between them need another investigation by electron microscope.

Certain pathological changes were associated only with heavy infection with microscopic cysts (S cruzi) infection.

These changes included muscular degeneration and focal leukocytic infiltration composed of eosinophils, macrophages and lymphocytes.