First molecular characterization of Sarcocystis spp. in cattle in Qena Governorate, Upper Egypt

Abstract

Cattle are intermediate hosts for several Sarcocystis species with different definitive hosts. The present study, to our knowledge, is the first to determine the prevalence of Sarcocystis infection and morphologically and molecularly identify Sarcocystis species in cattle in Qena Governorate, Upper Egypt. The samples were collected from the heart and oesophagus muscles of 84 slaughtered cattle (76 males and 8 females) aged between 11 months and 3 years from slaughterhouses in different localities in Qena Governorate, Upper Egypt. The samples were macroscopically and histologically examined, and the molecular identification of the species was performed using 18S ribosomal subunit DNA through PCR and DNA sequencing. Infection was detected in 72 out of 84 animals (85.7%) and was more prevalent in males (76.2%) than in females (9.5). Using light microscopy, the microscopic sarcocysts were observed to be thin-walled. Sequencing and genotyping revealed one isolate that had 99 and 100% identity, respectively, to Sarcocystis cruzi, while another isolate had 95 and 99% identity to Sarcocystis hjorti. The present study is the first to identify Sarcocystis infection in cattle in Qena Governorate, Upper Egypt both morphologically and molecularly. Sarcocystis cruzi and S. hjorti species were isolated from cattle, which is of veterinary importance and indicates that morphologically similar Sarcocystis species are genetically distinct. Additionally, the results show that Sarcocystis species are not host-specific.

Keywords: Hjorti; Molecular; Sarcocystis; Upper Egypt.

Fig. 1

Esophagus of a Sarcocystis-infected cattle showing microscopic cysts with thin cyst wall (cut section) stained with haematoxylin and eosin (× 63)

Fig. 2

Esophagus of a Sarcocystis-infected cattle showing microscopic cysts with thin cyst wall (longitudinal section) stained with haematoxylin and eosin (× 40)

Fig. 3

Heart muscles of a Sarcocystis-infected cattle showing microscopic cysts with thin cyst wall (× 40) (longitudinal section) stained with haematoxylin and eosin (× 63)

Fig. 4

The electrophoresis of the PCR product of 18S ribosomal gene of Sarcocystis in cattles samples presented bands at 600 bp

Fig. 5

DNA sequence alignment of 18S ribosomal RNA gene in isolated heart samples compared with the published sequences of S. cruzi on genebank (accession KT964008.1) showing sequence matches and gaps using BLAST software

Fig. 6

DNA sequence alignment of 18S ribosomal RNA gene in isolated heart samples compared with the published sequences of S. hjorti isolate CeS1.48 on genebank (accession No.KY973332.1) showing sequence matches and gaps using BLAST software

Fig. 7

Phylogeny of S. hjorti isolated in the present study with different Sarcocystis spp. recorded in cattles by the program Mega v.6. using maximum likelihood method based on 18S rRNA gene. The reference sequences accession numbers are included. Plasmodium vivax was used as outgroup