Distribution of Toxoplasma gondii tissue cysts in commercial cuts of pork.

Distribution of Toxoplasma gondii cysts in tissues used for human consumption was studied in 4 naturally infected pigs (acquired infections) and in 2 experimentally infected pigs. On the day of euthanasia, pigs with acquired toxoplasmosis had serum antibody titers of 160 to 1,280 against T gondii (modified agglutination test). Experimentally infected pigs were inoculated with 10,000 oocysts of the GT-1 strain of T gondii and were euthanatized 267 or 357 days after inoculation.

Effect of irradiation on the viability of Toxoplasma gondii cysts in tissues of mice and pigs.

Muscles from tongue, heart, and limbs of 14 pigs inoculated orally with Toxoplasma gondii oocysts were irradiated with 10, 20, 25, and 30 krad of gamma (cesium-137 and cobalt-60) irradiation. Viability of T gondii cysts was assayed by feeding porcine muscles to T gondii-free cats and/or by inoculation of sediment from acid-pepsin digested porcine muscle into mice. Cats fed 500-g samples of muscles irradiated with up to 20 krad shed T gondii oocysts.

Enzyme immunoassay detection of immunoglobulin M and G antibodies to Cryptosporidium in immunocompetent and immunocompromised persons.

Cryptosporidium is a parasite of the human gastrointestinal tract and has a worldwide distribution. We developed a sensitive and reproducible enzyme immunoassay for detection of serum IgG or IgM to Cryptosporidium. For IgG, 13 of 15 patients with cryptosporidiosis and 26 of 26 patients with cryptosporidiosis and AIDS were positive, whereas 57 of 60 presumably uninfected individuals were negative.

Types of myofibers parasitized in experimentally induced infections with Sarcocystis cruzi and Sarcocystis capracanis.

Eighteen calves were orally inoculated with either 200,000 or 225,000 sporocysts of Sarcocystis cruzi. Eight goats were orally inoculated with 20,000 sporocysts of S capracanis. Calves and goats were euthanatized at various times after inoculation, and portions of their right and left biceps femoris, right and left longissimus dorsi, myocardium, and tongue were frozen at -150 C in precooled isopentane and stored at -70 C.

Transection of the thoracic aorta: assessment of a trauma system.

A large, heavily populated area regionalized the care of critical trauma in 1980. To evaluate the system, we reviewed patient outcome for thoracic aortic transection due to blunt injury for the first 18 months of trauma system operation. Of the total of 86 patients, 43 were transferred to trauma centers, 8 to nontrauma centers, and 35 were either directly transported to the coroner or dead on arrival at the hospital.

Hematologic values in calves infected with Sarcocystis cruzi.

Calves were inoculated with 2 X 10(5) Sarcocystis cruzi sporocysts. Red cell mass decreased dramatically between Days 21 and 35 post-infection and plasma volume increased concurrently, so that blood volume did not change significantly. Mild reticulocytosis and increased pyrimidine 5' nucleotidase activity in erythrocytes occurred between Days 35 and 42.

Prevalence, transmission, and pathogenicity of Sarcocystis gigantea of sheep.

Between March and May 1983, tongues and esophagi of 355 adult ewes from Colorado and Idaho were examined for grossly visible sarcocysts. Sarcocysts of Sarcocystis gigantea were found in 35 sheep. Cats fed sarcocysts from these naturally infected sheep shed sporocysts in their feces.

Disseminated visceral coccidiosis in sandhill cranes.

Disseminated visceral coccidiosis (DVC) caused by Eimeria spp was first recognized as a disease entity in captive sandhill cranes (Grus canadensis) and whooping cranes (G americana) at the Patuxent Wildlife Research Center. Because cranes produced at the Center are reintroduced to the wild to augment wild populations, studies involving both experimentally induced and natural infections were initiated to determine the potential or actual occurrence of DVC in wild Gruidae. Nine sandhill cranes dosed orally with eimerian oocysts of wild origin developed lesions characteristic of DVC.

The effects of reducing conditions, medium, pH, temperature, and time on in vitro excystation of Cryptosporidium.

Whereas excystation of sporozoites from oocysts of most coccidian species requires exposure to reducing conditions followed by pancreatic enzymes and bile salts, sporozoites of a bovine isolate of a bovine isolate of Cryptosporidium excysted without exposure to either reducing conditions or to pancreatic enzymes and bile salts. Without prior exposure to reducing conditions, a high percent excysted after incubation in a mixture of trypsin and bile salts in Ringer's solution; fewer excysted after incubation in tap water, even fewer after incubation in salt solutions, and none after incubation in saliva. Excystation, generally greater at pH 7.

Persistence of encysted Toxoplasma gondii in tissues of pigs fed oocysts.

Ten pigs were fed 100 to 10,000 Toxoplasma gondii oocysts. Two pigs died 7 and 11 days later, and 8 pigs were euthanatized at days 38, 38, 91, 126, 168, 169, 170, and 171. From the euthanatized pigs, portions of 15 organs digested in pepsin-HCl solution were inoculated into mice, as a bioassay for viable T gondii.

Protective immunity against clinical sarcocystosis in cattle.

Five experiments involving 50 calves (Bos taurus) were conducted to determine if oral infection with sporocysts of the pathogen Sarcocystis cruzi or the non-pathogen Sarcocystis hirsuta would stimulate development of a protective immunity against illness or death from challenge infection with large numbers of S. cruzi sporocysts. Four experiments involved Holstein calves housed in individual pens in isolation buildings; one experiment involved Hereford calves on an open range.

Humoral and cellular immune responses in cattle and sheep inoculated with Sarcocystis.

Cattle inoculated with Sarcocystis bovicanis (= Sarcocystis cruzi) and sheep inoculated with Sarcocystis ovicanis were monitored for the appearance of Sarcocystis-specific antibodies and lymphocytes in the peripheral circulation. Anti-Sarcocystis antibody was identified by enzyme-linked immunosorbent assay, whereas antigen-reactive lymphocytes were discerned by an in vitro lymphocyte blastogenic assay. The antigens used were the soluble fraction recovered from disrupted bradyzoites of mature sarcocysts.

Experimental Sarcocystis ovicanis infection in lambs: salinomycin chemoprophylaxis and protective immunity.

Salinomycin, administered prophylactically, was effective in controlling clinical sarcocystosis resulting from infection with Sarcocystis ovicanis in two experiments involving a total of 50 lambs. In each experiment, five lambs were used in each of five test groups--uninoculated and unmedicated, inoculated and unmedicated, uninoculated and medicated (2 mg/kg), inoculated and medicated (2 mg/kg), and inoculated and medicated (1 mg/kg). Salinomycin was included in the feed of each medicated group for 30 days beginning on the day of oral inoculation with 10(6) S.

Effects of sarcocystosis on milk production of dairy cows.

Sixteen multiparous Holstein cows were allotted randomly to four groups of four cows each. Cows in 1 and 2 were uninfected. Those in 3 received 60,000 and those in 4 received 120,000 Sarcocystis bovicanis sporocysts per os approximately 30 days before the expected onset of lactation to produce nonclinical and clinical infections in 3 and 4, respectively.

Attempted transmission of Sarcocystis bovicanis from cows to calves via colostrum.

Sixteen pregnant cows were divided into four equal groups. Groups 1 and 2 were uninoculated controls; Groups 3 and 4 received 60,000 and 120,000 S. bovicanis sporocysts per os, respectively, about 30 days before expected parturition.

Development of Sarcocystis fayeri in the equine.

Eight ponies and a horse were inoculated orally with sporocysts of Sarcocystis fayeri from dogs. They were examined for clinical signs of infection and killed 10, 15, 20, 25, 30, 50 (horse), 77, 101, and 156 days after inoculation (DAI). Elevated temperature was observed in three ponies 20 and 26 DAI and anemia was observed in three ponies and the horse 15 to 69 DAI.

Sarcocystosis in an aborted bovine fetus.

Sarcocystosis was diagnosed in an aborted bovine fetus. Immature and mature schizonts of Sarcocystis were disseminated in the vascular endothelium of all organs, but especially the brain. Microscopic granulomas, focal gliosis, and petechial hemorrhages in the neuropil were scattered in the brain.

Infectivity of sarcocystis spp. from bison, elk, moose, and cattle for cattle via sporocysts from coyotes.

Bison bison (bison), Cervus canadensis (elk), Alces alces (moose), and Bos taurus (cattle) musculature containing Sarcocystis spp. cysts was fed to laboratory raised Canis latrans (coyotes), Sporocysts collected from the feces of coyotes fed musculature of each of the ruminant species were fed to four groups of three laboratory-raised domestic calves, respectively, to determine if Sarcocystis spp. was transmissible from wild to domestic ruminants and if so, to compare clinical signs of infection and morphologic features of cysts with those resulting from infection with Sarcocystis bovicanis.

Toxoplasmosis update and public health implications.

Toxoplasma gondii has a coccidian life cycle in the intestine of domestic and wild felids that includes a series of asexual and sexual stages and an oocyst stage that is shed in the feces. Oocysts complete their development outside the body, eventually becoming infective for about 350 species of vertebrates including cats and man. The effects of climate on oocyst survival and the physical and biological means of oocyst dispersal are discussed.

Sarcocystis spp. in white-tailed deer. I. Definitive and intermediate host spectrum with a description of Sarcocystis odocoileocanis n. sp.

Sporocysts containing four sporozoites and measuring (avg.) 15.2 micrometers X 10.

Hematology of experimental acute Sarcocystis bovicanis infection in calves. II. Serum biochemistry and hemostasis studies.

Of four Holstein-Friesian calves infected with 200,000 sporocysts of Sarcocystis bovicanis, three become ill and died on days 35, 55, and 59 of a 63-day experiment. No control calves became ill or died. Serum biochemicals and hematologic indicators of hemostasis from both groups were measured throughout the experiment.