Sarcocystis spp infection in Philippine water buffaloes (Bubalus bubalis).

In a survey of sarcocysts in muscle tissues obtained from 142 water buffaloes, 65% of the carcasses had sarcocysts. Macroscopic and two forms of microscopic sarcocysts, the spindle-shaped or fusiform sarcocysts commonly occurring in the muscles of the esophagus, throat and limbs, and the globular to oval-shaped sarcocysts which were the dominant form in the diaphragm and cervical muscle tissues were noted. Ultrastructural analysis of macroscopic and microscopic sarcocysts and their cyst wall revealed two distinct species of Sarcocystis: the macroscopic species, Sarcocystis fusiformis which has been previously reported in Philippine carabaos possessing highly dendritic cauliflower-like projections emanating from the primary cyst wall, with annulated microfilaments and numerous electron dense granules: and the Sarcocystis levinei (Dissanaike and Kan, 1978) Huong, Dubey and Uggla. 1997 exhibiting a cyst wall with undulating and hair-like villar protrusions with expanded or dome-shaped base, intermediate finger-like, and distal tapering segments which at some points join to form conical tufts. Our findings represent the first report of S. levinei in the country supported with ultrastructural analysis of the sarcocysts and cyst wall, and likewise refute earlier published reports that all microscopic sarcocysts in Philippine carabaos are developing forms of the macroscopic species, S. fusiformis. Histopathological changes such as displacement and necrosis of the surrounding host muscle tissue were observed with macroscopic sarcocysts and histologically processed tissue samples containing microscopic fusiform sarcocysts. Necrotic myofibrils and mitochondria were evident in ultrathin sections.

A survey of bovine, bubaline and swine sarcocystosis in the Philippines.

In a survey conducted from January to December, 1994, muscle tissues in 12 out of 22 slaughtered carabaos ages 8-17 years old and obtained from the Food Terminal Inc, Abbatoir in Laguna showed numerous white and creamy elliptic-shaped soft bodied macrocysts in the throat muscles. Microscopic examination of the throat and cardiac muscle tissues revealed the presence of fusiform-shaped microcysts. Our observations are consistent with previous reports incriminating Sarcocystis fusiformis as the most important etiologic agent of bubaline sarcocystosis in the country. In a survey of bovine sarcocystosis in muscle tissues of imported Australian cattle (Brahman Breed) and native cattle obtained from various slaughter houses in Manila and suburbs, prevalence rates of 17% (98/577) and 3% (1/31) were noted, respectively. Sarcocysts were predominant in skeletal muscles and to a lesser extent in cardiac, esophageal and diaphragm muscle tissues. Light microscopic examination of sarcocysts morphology suggests Sarcocystis cruzi (= Sarcocystis bovis), and Sarcocystis hominis (= Sarcocystis bovihominis) or Sarcocystis hirsuta (= Sarcocystis bovifelis) as the likely etiologic agents of bovine sarcocystosis in the country. Of the 225 swines examined, only muscle tissues from a 6-month old swine revealed very young sarcocysts (= metrocytes). A review of available documented studies on sarcocystosis suggests that to date, our findings may represent the first data on the prevalence of bovine and swine sarcocystosis in the Philippines.