Genetic diversity and haplotypes of paediatric hydatid cyst isolates and first occurrence of E. canadensis (G6/G7) in paediatric cases in Turkey

A pilot study on the epidemiology, diagnosis and characterization of Echinococcus granulosus sensu lato in sheep, goats and dogs in Siirt province of Türkiye revealed remarkable adaptation of Echinococcus canadensis (G6/G7) in goats

Cystic echinococcosis (CE), caused by Echinococcus granulosus sensu lato (s.l.), represents one of the most significant zoonotic diseases globally, affecting both humans and animals. The objective of this study was to ascertain the prevalence of E. granulosus sensu lato in sheep and goats in a pilot region with a one-year slaughterhouse follow-up period and to determine the genetic differences and haplotypes among sheep, goat, and dog isolates. To this end, the prevalence of CE cysts was determined by monitoring the slaughter of sheep and goats at least three days a week at a slaughterhouse in the Siirt province of Türkiye during 2023. Additionally, faecal samples were collected from stray dogs and analysed using both flotation and molecular techniques. The presence of CE cysts was identified in 569 (11.12 %) of the 5119 sheep and 66 (2.31 %) of the 2860 goats after slaughtering. The highest positivity was observed in November (20.39 %), while the lowest was recorded in July (5.62 %). Of the sheep that detected positive, 25 (4.39 %) were less than one year old, while 544 (95.61 %) were older than one year. Of the infected sheep, 26 (4.57 %) were male and 543 (95.43 %) were female. 204 (35.85 %) sheep exhibited fluid-filled CE cysts, 338 (59.40 %) displayed calcification, and 27 (4.75 %) demonstrated the presence of newly developed cysts. The highest positivity was observed in December (5.83 %), while the lowest was recorded in May (0.62 %) in goats. Of the positive goats, two (3 %) were less than one year old, while the remaining 64 (97 %) were older than one year. Of the goats infected with CE cysts, 10 (15.15 %) were male and 56 (84.85 %) were female. Of the cysts, 56.1 % were fluid-filled, 42.4 % were calcified and 1.5 % were newly developed. Following DNA sequence analysis of CE cyst isolates obtained from the slaughterhouse, all 61 sheep sequences were identified as E. granulosus s.s. (G1/G3). Of the 13 goat isolates, seven were identified as E. granulosus s.s. (G1/G3), while the remaining six were classified as E. canadensis (G6/G7). The centrifugal flotation method was employed to detect the presence of Isospora spp. oocysts in eight dogs, Toxocara canis and hookworm eggs in three dogs each, and Dipyllidium caninum eggs in one dog. A total of 54 dog faeces were examined. No Taeniid eggs were observed in any of the dogs. Following PCR analysis of the mt-CO1 gene region in the dog faecal samples, four samples were positive for a 875 bp band. Only one of these bands was suitable for sequence analysis, which confirmed it as E. granulosus s.s. (G1/G3).

Molecular discrimination of G1 and G3 genotypes of Echinococcus granulosus sensu stricto obtained from human, cattle, and sheep using the mitochondrial NADH dehydrogenase subunit 5 marker

Cystic echinococcosis (CE) is a common zoonotic disease caused by the larval form of Echinococcus granulosus sensu lato. This study determined the genotype and haplotype differences using the NADH dehydrogenase subunit 5 gene in hydatid cyst samples. Human (n = 12), cattle (n = 28), and sheep (n = 31) hydatid cyst isolates were included. Seventy-one genomic DNA samples were successfully extracted, and a 759 bp mitochondrial NADH dehydrogenase subunit 5 gene fragment was amplified by PCR. Following the sequence analysis, E. granulosus sensu stricto isolates were identified as G1 (n = 61) and G3 (n = 10). A total of 23 haplotypes were obtained from the 71 E. granulosus s.s. G1 and G3 samples. The main haplotype was Hap01 (60.56 %), which consisted of the G1 genotype. The second largest haplotype was Hap04, which consisted entirely of the G3 genotype. Hap14 acted as a bridge between the G1 and G3 genotypes. This study identifies G1 as the dominant genotype in humans and farm animals in Turkey. High haplotype and nucleotide diversity in genotypes were observed. Additionally, this is the first report on the phylogeography and gene flow models of the E. granulosus s.s. population in Turkey using the NADH dehydrogenase subunit 5 gene, the best marker distinguishing between G1 and G3 genotypes.

Co-infection of Echinococcus equinus and Echinococcus canadensis (G6/7) in a gray wolf in Turkey: First report and genetic variability of the isolates

Cystic echinococcosis (CE) is an important zoonotic diseases caused by larval form of Echinococcus granulosus sensu lato. The material of this study was the gray wolf (Canis lupus), which was found dead in the rural area of Bingol province of Turkey. The animal was brought to Veterinary Faculty for necropsy and many of adult Echinococcus spp. obtained. A total of 9 whole adult worms were morphologically examined under the microscope, gDNA was isolated from individual samples, a partial mt-CO1 gene fragment (875 bp) was amplified with PCR and sequenced. According to the phylogenetic analysis, six worms were characterized as E. equinus, while three were reported as E. canadensis (G6/7). It was found that the haplotypes of both species were similar to previously published haplotypes. This is the first report in which E. equinus and E. canadensis (G6/7) adult parasites were detected together in a gray wolf's intestine. The findings are important in that it draws attention to the importance of wild cycle in the spread of CE.