Genetic and morphometric categorization ofTaenia ovisfrom Sheep in Iran

Abstract

Little is known about the genetic and morphological characters of Taenia ovis. The purpose of the present study was to characterize sheep isolates of T. ovis using rostellar hook morphometry as well as mitochondrial genes sequence analysis. Ninety sheep specimens of Cysticercus ovis were collected from 18 slaughterhouses in Iran. The mean ± s.d. for total length of large and small hooks were 174.1 ± 6.4 and 116.7 ± 5.4 µm, respectively. CO1 and 12S rRNA sequence analysis showed 11 and nine haplotypes, respectively. The level of pairwise nucleotide variations between individual haplotypes of CO1 and 12S rRNA genes were 0.3–1.1 and 0.2–1.0%, respectively. Level of nucleotide variation in CO1 and 12S rRNA between T. ovis haplotypes from present study and eight other Taenia species was found to be 11.3–17.8 and 5.3–16.3%, respectively. Phylogenetic analysis clustered all T. ovis isolates into a single clade comprised of the all CO1 and 12S rRNA haplotypes. CO1 nucleotide difference between T. ovis ovis and T. asiatica was 13.6% that is lesser than the corresponding difference between T. ovis ovis and T. ovis krabbei, warranting the designation of two separate species as T. ovis and T. krabbei. Interclass correlation coefficients showed that there was no significant association between rostellar hook length variation and the variability of the mitochondrial genes.

New insights into the prevalence and phylogenetic diversity of Cysticercus ovis isolates in sheep from Sulaymaniyah, Iraq

“…The presented study indicated a fairly low degree of variation in the COX1 gene of T. ovis compared to other isolates of this taeniid. In addition, pairwise comparison of the isolates of T. ovis from this experiment as well as available mitochondrial sequences from Iranian ( 23 ) and New Zealand ( 17 ) sheep isolates indicated 0.0–2.0% and 0.0–1.0% nucleotide difference in the COX1 gene, respectively ( Fig.2 ). Therefore, the phylogram showed that the present research’s Iraqi isolates were comparable to other isolates of T. ovis , as they share 98.95–99.74% identity with those from New Zealand and Iran.…”

“…An approximately 400 bp-long fragment of the mitochondrial COX1 gene was amplified by means of a primer pair, comprising JB3 5ʹ-TTTTTTGGGCAT CCTGAGGTTTAT-3ʹ as the forward one and JB4.5 5ʹ-TAAAGAAAGAACATAAATGAAAAATG-3ʹ as the reverse one ( 2 ). The mitochondrial DNA was amplified using f-Pfu DNA polymerase according to the manufacturer’s protocol (SBS Genetech Co., Beijing, China), under the conditions previously described ( 23 ). The PCR products were confirmed via gel electrophoresis on 1.5% agarose gels (TBA, 0.5%) that were stained with GoodView Nucleic Acid Stain (SBS Genetech Co.).…”

“…Infection with T. ovis occurs globally, and research has documented it in Canada ( 5 ), China ( 25 ), England ( 6 ), Ethiopia ( 26 ), Iran ( 12 , 23 ), Egypt ( 1 ), and New Zealand ( 15 ). In Iraq, the epidemiology of C. ovis remains unknown, and there was no report describing this parasite in sheep.…”