First identification of Sarcocystis hominis in Iranian traditional hamburger

Zoonotic Sarcocystis

Apicomplexan species in the genus Sarcocystis form tissue cysts, in their intermediate hosts, similar to those established in chronic toxoplasmosis. More than 200 species are known, but just a few are known to threaten human health owing to infection in livestock species. Intestinal sarcocystosis occurs when people consume raw or undercooked beef contaminated with Sarcocystis hominis or S. heydorni or undercooked pork contaminated with S. suihominis. Those infections may cause mild enteritis, but most infections are thought to be asymptomatic. People also become dead-end (intermediate) hosts for non-human Sarcocystis spp. after accidentally ingesting sporocysts, leading to extraintestinal sarcocystosis. The clinical spectrum may range from asymptomatic muscle cysts to a severe, acute, eosinophilic myositis associated with systemic symptoms with peripheral eosinophilia. Most human cases have been described from Southeast Asia, but Sarcocystis parasites have a worldwide distribution, especially where livestock is raised, and human infections in other areas have been described but may be underrecognized.

First molecular characterization and morphological aspects of Sarcocystis fusiformis infecting water buffalo Bubalus bubalis in Egypt

Fresh muscle samples from water buffalo (Bubalus bubalis) aged 2-15, from Giza Province, Egypt; were examined for Sarcocystis infection. Macroscopic ovoid sarcocysts embedded in the muscle tissues of the examined buffaloes were detected; they measured 152-230 (210 ± 7) μm in length and 37-119 (95 ± 3) μm in width. The esophagus was the most infected organ followed by the diaphragm, and tongue, while the heart muscles were the least infected. The cyst cavity was compartmentalized by septa derived from the ground substance located under the primary cyst wall. Using transmission electron microscopy, the primary cyst wall bordered sarcocysts were determined to be 0.08-0.22 μm in thickness, raised from the parasitophorous vacuolar membrane, and surrounded by a secondary cyst wall of host origin. The primary cyst wall had irregular wall folds with numerous cauliflower-like projections of variable sizes and shapes accompanied by knob-like electron-dense elevations. 18S rRNA gene expression studies confirmed that the present parasite isolates belonged to the genus Sarcocystis. The sequence data showed significant identities (>90%) with archived gene sequences from many Eimeriidae organisms, and a dendogram showing the phylogenetic relationship was constructed. The most closely related species was Sarcocystis fusiformis KR186117, with an identity percentage of 98%. The recovered sequences were deposited in the GenBank under the accession number MG572125. The present study, to our knowledge, is the first collective ultrastructural and molecular study that confirmed the taxonomy of sarcocysts isolated from water buffaloes in Egypt as Sarcocystis fusiformis.

Molecular identification of Sarcocystis species in raw hamburgers using PCR-RFLP method in Kashan, central Iran

The prevalence of bovine Sarcocystosis is high in the most regions of the world. It can be a human health problem due to consumption of raw or under cooked hamburgers or other bovine meat products. This study was carried out to investigate the prevalence and species identification of Sarcocystis among of hamburgers, using PCR-RFLP methods in Kashan, central Iran. Overall 200 raw industrial hamburgers samples with at least 60% meat were randomly collected from nine different brands in Kashan, central Iran. The genomic DNA was extracted and a PCR-RFLP method was used to amplify an approximately 900 bp fragment at the 18S rRNA(SSU) gene, restriction enzyme BclI was used for species identification. The results showed that 58 (29%) of 200 tested hamburger samples were infected to Sarcocystis spp. The prevalence rate was 31.25 and 26.9% in the hamburgers with 90 and 60-75% meat, respectively. According to PCR-RFLP analysis, 43 (74.1%) of the 58 isolates were Sarcocystis cruzi, 12 (20.7%) showed co-infection to S. cruzi and Sarcocystis hirsuta, 2 (3.5%) was mixed infected to S. cruzi and Sarcocystis hominis, 1 (1.7%) showed the pattern of mix infection to three species. This study revealed one-third of industrial hamburger were infected to S. cruzi or mixed infection of S. cruzi with other bovine sarcocytosis. To prevent cattle infection, the possible ingestion of the disposal sporocyst stage from dogs must be eliminated. Although in this study, the prevalence of S. hominis was low and cannot be considered as a major zoonosis, it should be recommended avoiding eating under cooked hamburger and other bovine meat products to prevent human infection.