Comparison of Protoscolex Hook Morphologies in Human, Sheep, Cattle Echinococcus granulosus Isolates

Abstract

Objective: Cystic echinococcosis (CE) is an important parasitic infection caused by Echinococcus granulosus (E. granulosus) larvae, adults of which live in Canidae. Although CE is observed in all over the world, it is more prevalent in developing and underdeveloped nations.
 Material and Method: This study was conducted on a total of 60 cyst samples, including 20 sheep and 20 cattle slaughtered in the abattoir and 20 patients operated with the diagnosis of KE in University Medical Center between the dates June 2018 and April 2019. The collected cyst fluids were centrifuged and protoscolices were collected. For each of these hosts, 20 large and 20 small hooks were examined. Large hook length (LHL), small hook length (SHL), large hook width (LHW), small hook width (SHW), large hook blade length (LHBL), small hook blade length (SHBL) were measured. The measurements were made by a single person, taking into account the characteristics specified by Hobbs et al. (1990). The results were evaluated with the SPSS program.
 Results: The average of human, sheep and bovine LHL measurements were 21.710 ± 1.073 μm, 24.322 ± 1.073 μm, 25.223 ± 1.073 μm; SHL measurements were 16.946 ± 0.840 μm, 20.746 ± 0.911 μm, 21.199 ± 0.977 μm; LHW measurements were 5.437 ± 0.358 μm, 7.817 ± 0.729 μm, 8.528 ± 0.589 μm, respectively; SHW measurements were 7.229 ± 0.631 μm, 6.417 ± 0.507 μm, 6.488 ± 0.463 μm, respectively; LHBL measurements were 13.236 ± 0.746 μm, 13.862 ± 0.767 μm, 13.345 ± 0.728 μm; SHBL measurements were determined as 8.918 ± 0.471 μm, 9.414 ± 0.483 μm, 9.457 ± 0.476 μm, respectively. The length, width and blade lengths of large and small hooks isolated from human, sheep and cattle were significant difference between all groups. When hook morphology measurements were grouped in pairs as human-sheep, human-cattle and sheep-cattle and analyzed statistically; It was determined that LHL, SHL, SHW and SHBL were significantly different between human-cattle and human-sheep, but not between sheep-cattle. It was found that LHW was significantly different between human-cattle and sheep-cattle, while LHBL was significantly different only between human-sheep.
 Conclusion: The morphological features of the large and small hooks of E. granulosus may represent morphological adaptation in vertebrate hosts. For this reason, it is thought that morphological parameters can be useful in the differentiation of isolates and can be used together with molecular studies in the future