Prevalence and Molecular Characterization of <i>Echinococcus granulosus</i> Sensu Lato Eggs among Stray Dogs in Sulaimani Province—Kurdistan, Iraq

Abstract

The main goal of this study was to estimate the prevalence of Echinococcus granulosus among stray dogs, as well as its potential impact on the environmental contamination in the Kurdistan-Iraq using microscopic examination and the Copro-PCR method. The presence of taeniid eggs was recorded in 400 dog faeces collected from the four different regions in the Sulaimani Governorate. The parasite eggs were recovered from fresh and aged faecal samples of the dogs using two isolation techniques, a flotation method (Sheather’s solution, modified; specific gravity: d = 1.27) and a sedimentation method (formal-ether) in which the sediments from dog faeces were collected. Both methods were used for Copro-PCR to detect the presence of Echinococcus species egg through DNA using common primers designed to amplify a partial gene of cytochrome oxidase subunit 1 (COX1). The results of the microscopic examination showed a higher prevalence rate, i.e., 97 (24.25%) of E. granulosus among stray dogs generally in Sulaimani Governorate. The prevalence of E. granulosus among stray dogs according to the district area was 40, 24, 23, and 20.8% in Rzgari, Kalar, Sulaimani, and Halabja, respectively. The positive samples (n = 50) were selected for molecular confirmation, the DNA was extracted from the sediment of the positive samples and 40 (80%) samples were successfully amplified by polymerase chain reaction. The sequences show that all samples belong to the Echinococcus granulosus sensu lato (G1–G3), with slight genetic variation. It was concluded that the sediment of dog faeces can be used for DNA extraction, which is a new method that increases the sensitivity of the test, and the amount of DNA yield would be higher than the routine method, which directly uses faeces of the dogs. In addition, the molecular diagnosis was more sensitive than the microscope examination for the presence of E. granulosus eggs. The prevalence of E. granulosus in both the final hosts and the intermediate hosts must be regularly monitored.

Keywords

• <i>Echinococcus granulosus</i>
• molecular identification
• PCR
• stray dogs