Sequence phylogenetic analysis and associative genetic diversity of Sarcocystis hirsuta based on 18S rRNA gene

Background Sarcocystis hirsuta, a tissue cyst-forming coccidian parasite of cattle, is worldwide in distribution. In spite of its global presence, limited literature is available on its characterization studies. No literature is available from India on molecular aspects of S. hirsuta. The present study was designed to characterize the isolates of S. hirsuta on the 18S gene locus. A total of five isolates of S. hirsuta were characterized. PCR products were cloned, sequenced, and compared with other sequences across the world. A phylogenetic tree was constructed based on the maximum parsimony (MP) method with the tree–bisection–regrafting (TBR) algorithm. Results An appreciable genetic variability was noticed between various S. hirsuta isolates at the 18S gene locus. Sequences generated from the present study (MN121567–MN121571) represented two haplotypes with 99.74–100.00% nucleotide homology within themselves. Alongside, a nucleotide homology of 97.82–99.92% was observed between Indian isolates and isolates across the globe. The two haplotypes were markedly distinct from each other with 3 nucleotide substitutions within themselves. Overall, Indian isolates of S. hirsuta were close to those from China and Vietnam than to those from New Zealand, Brazil, and Germany. Conclusion The present communication describes the first report of phylogenetic characterization of S. hirsuta from India. The findings are very much important in delineating the evolutionary phylogenetics of S. hirsuta.

Prevalence of Sarcosporidiosis in Carcasses of Cattle Slaughtered at the Eucalyptus Slaughterhouse-Algeria

Sarcosporidiosis is a parasitic disease due to the development of cystogenic coccidia of the genus Sarcocystis with dixene evolution and muscular localization, which can cause losses in cattle and generate an intestinal infection in domestic carnivores (dog, cat) and humans. The objective of our study was to determine the prevalence of Sarcocystis spp on 149 bovine carcasses at the Eucalyptus slaughterhouse in Algiers by macroscopic and microscopic examination and to evaluate the influence of certain risk factors (age, sex, breed and origin). Samples of esophagus and diaphragms were taken from slaughtered cattle and analyzed by enzymatic (pepsin) digestion and histological technique. The macroscopic examination was negative during carcasses inspection while the microscopic examination showed a prevalence of 100% for enzymatic digestion by revealing bradyzoites in the form of bananas and 47.7% at the histology with the detection of thin-walled cysts of S. cruzi (98.6%), of thick-walled cysts of S. hominis (15.5%) which was the zoonotic species and of S. hirsuta (1.39%). The risk factors studied significantly influenced the prevalence of Sarcocystis sp. This study revealed for the first time in the diaphragm a cyst of Sarcocystis hirsuta.

Caracterização molecular de Sarcocystis spp. em amostras de carne

RESUMO: A sarcocistose é uma doença distribuída mundialmente, podendo acometer aves, répteis e diversos mamíferos, incluindo o homem. O objetivo desse trabalho foi detectar a presença de Sarcocystis spp. e caracterizar as espécies encontradas em 375 amostras de produtos cárneos (filé mignon bovino, carne moída bovina e salame colonial). Para isso, foi realizada a detecção do parasita através da técnica de PCR para amplificação parcial do gene 18S rRNA e sua caracterização molecular utilizando o polimorfismo no comprimento do fragmento de restrição (RFLP) com as enzimas de restrição Bcl I, Rsa I e Alu I. A ocorrência de Sarcocystis spp. foi de 17% (64/375) do total de amostras testadas pelo PCR. Entre os produtos cárneos avaliados, 5,6% (7/125) das amostras de filé mignon, 12,8% (16/125) de carne moída e 32,8% (41/125) de embutido colonial, foram positivas para presença do DNA do Sarcocystis spp. Entre estas amostras positivas, as espécies caracterizadas foram Sarcocystis hirsuta e Sarcocystis hominis com prevalências de 93,7% (60/64) e 6,3% (4/64), respectivamente. Considerando à relevância da sarcocistose na área da saúde pública, a ocorrência de S. hominis encontrado neste estudo, pode ser um fator de risco para a contaminação humana. Porém, a presença do DNA deste protozoário não significa necessariamente potencial de infecção aos humanos, pois cuidados nos processos de fabricação podem reduzir a viabilidade dos cistos.

Chronic Polymyositis Associated with Disseminated Sarcocystosis in a Captive-born Rhesus Macaque

A 2–year-old, captive-born, clinically healthy male, rhesus macaque, was euthanatized as part of an experimental study. At necropsy, diffuse pale streaking of the trunk, lumbar, and limb muscles were noted macroscopically. On histology, numerous elongated cysts that contained crescent-shaped basophilic spores were found in the fibers of skeletal muscles. Scattered affected myofibers were degenerate and accompanied by eosinophilic-to-granulomatous inflammation. Sarcocysts had prominent villus-like projections with the morphology of a type 11 sarcocyst wall similar to Sarcocystis neurona but possessing many more villus microtubules than is reported for S. neurona. In addition, bradyzoites were very long, up to approximately 12 um in length. The protozoa were consistent with a Sarcocystis sp., based on histology and ultrastructure, however, a definitive identification of the species was not possible. Nonspecific immunohistochemical crossreaction with Sarcocystis cruzi antisera was observed. The 18S ribosomal deoxyribonucleic acid sequence showed 91% similarity to Sarcocystis hominis, 90% similarity to Sarcocystis buffalonis, and 89% similarity to Sarcocystis hirsuta. Interestingly, the ITSI sequence showed very little homology to any sequence in GenBank, suggesting that this is possibly a unique Sarcocystis sp. Sarcocystosis is often considered an incidental finding, particularly in wild-caught animals, with little clinical significance. However, as demonstrated in this report and others, disseminated sarcocystosis can occur in captive-born rhesus macaques with or without clinical signs. In some cases interference with research results can occur; including death in fulminant cases.

In vitro cultivation of the vascular phase of Sarcocystis hirsuta (Apicomplexa)

Sporozoites of Sarcocystis hirsuta (Apicomplexa), although they also penetrated into bovine monocytes, developed to the schizogonous phase only in bovine pulmonary artery endothelial cells. Schizonts were evident beginning 14 days after sporozoite inoculation (DAI) and persisted to 62 DAI, when experiments were terminated. Merozoites and schizonts were most numerous 35–53 DAI. The number of schizogonous generations was not determined. In vitro cultivation of schizonts of S. hirsuta will facilitate comparisons with development of S. cruzi, and this will aid elucidation of mechanisms of pathogenesis and immunologic responses caused by these two important cattle parasites.