Related Experiment Video
Updated: Aug 18, 2026
Using Eggs from Schistosoma mansoni as an In vivo Model of Helminth-induced Lung Inflammation
Published on: June 5, 2012
Experimental microcyst sarcocystis infection in lambs: serology and immunohistochemistry
Abstract:
Density gradient centrifugation using a performed self generated gradient of colloidal silica enabled the isolation of microscopic sheep sarcocystis cystozoites, free from heart muscle contamination. The efficiency of separation of cystozoites from residual heart muscle after digestion in pepsin and hydrochloric acid was 63 to 92 per cent. Antigens from cystozoites were used on enzyme-linked immunosorbent assays (ELISA) of plasma from six coccidia-free lambs infected once orally with 70,000 microcystic sheep sarcocystis sporocysts and for raising antisera in rabbits. Use of an anti-sheep IgM conjugate in the ELISA showed that anti-sarcocystis IgM production was transitory, appearing five to 10 days after infection, peaking in concentration at 42 days and following the peak of the acute phase of infection (32 and 33 days) in the lambs. In contrast, total anti-sarcocystis immunoglobulins, detected by ELISA, increased from five to 21 days after infection and continued to increase until the lambs were killed (the last at 81 days) and was more useful in diagnosing chronic infection. No cross reactions between microcystic sheep sarcocystis and Toxoplasma gondii or Eimeria species of sheep were observed. A peroxidase anti-peroxidase test, using rabbit anti-sarcocystis sera, detected second generation meronts and sarcocysts in fixed tissues from infected lambs making it useful for the diagnosis of acute or chronic disease post mortem.
Insights
This study isolated sheep Sarcocystis cystozoites using density gradient centrifugation. Enzyme-linked immunosorbent assays (ELISA) detected IgM and total immunoglobulins, aiding diagnosis of acute and chronic infections.
Area of Science:
- Veterinary Parasitology
- Immunology
- Biotechnology
Background:
- Sarcocystis infections pose a significant challenge in sheep farming.
- Accurate diagnostic methods are crucial for managing Sarcocystis outbreaks.
- Previous diagnostic techniques lacked specificity and efficiency.
Purpose of the Study:
- To isolate pure Sarcocystis cystozoites from infected sheep heart muscle.
- To develop and validate enzyme-linked immunosorbent assays (ELISA) for diagnosing Sarcocystis infection in lambs.
- To differentiate between acute and chronic Sarcocystis infections using serological markers.
Main Methods:
- Density gradient centrifugation with colloidal silica for cystozoite isolation.
- Pepsin and hydrochloric acid digestion of heart muscle tissue.
- Enzyme-linked immunosorbent assays (ELISA) using cystozoite antigens and anti-sheep IgM/total immunoglobulin conjugates.
- Peroxidase anti-peroxidase (PAP) test for tissue diagnosis.
Main Results:
- Efficient isolation of Sarcocystis cystozoites (63-92%) achieved.
- Anti-Sarcocystis IgM was transient, indicating acute infection.
- Total anti-Sarcocystis immunoglobulins increased over time, useful for chronic infection diagnosis.
- No cross-reactivity observed with Toxoplasma gondii or Eimeria species.
- PAP test detected meronts and sarcocysts in infected lamb tissues.
Conclusions:
- Density gradient centrifugation is effective for isolating Sarcocystis cystozoites.
- ELISA provides a reliable method for diagnosing acute and chronic Sarcocystis infections in sheep.
- The developed serological assays are specific and do not cross-react with other common ovine parasites.
- The PAP test is valuable for post-mortem diagnosis of Sarcocystis in sheep.
