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

Zoonotic Echinococcus granulosus sensu lato genotypes G6 and G7: new insights from the global mitogenome analysis

Cystic echinococcosis is a severe zoonotic disease caused by different species and genotypes belonging to the Echinococcus granulosus sensu lato (s.l.) complex. Among these, genotypes G6 and G7 are the second most common cause of human cystic echinococcosis. One of the very first steps towards understanding the epidemiology of G6 and G7 is to study their genetic and host diversity, population structure and phylogenetic relationships. For this, we sequenced near-complete mitochondrial genomes (12,850-12,856 bp) of 72 new G6 and G7 samples from eight countries and six host species, including humans. By adding 103 sequences from previous studies, the total dataset for further analyses comprised of 175 sequences from 20 countries and seven host species. This is the most comprehensive global mitogenome study of Echinococcus granulosus s.l. G6 and G7 to date. The results of this work revealed: (i) a new divergent haplogroup G6b from Mongolia; (ii) the subdivision of genotype G6 into two major haplogroups: G6a (the nominal haplogroup) and G6b (the Mongolian haplogroup); (iii) highly divergent haplotypes of G6 and G7; (iv) the first molecularly confirmed findings of genotype G7 in camel; (v) genotype G7 in sheep - a rare species for G7; (vi) the importance of using long DNA sequences in phylogenetic analysis.

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).

Prevalence, molecular characterisation and phylogenetic analyses of hydatid cysts and cysticercus tenuicollis isolates and first report of E. canadensis (G6/G7) in wild boars in Bingol province, Türkiye

Wild boars can directly or indirectly transmit numerous zoonotic helminths to humans in rural communities as they serve as reservoir hosts. This study was conducted to determine the occurrence and molecular characterisation of cystic metacestode forms of helminth parasites in wild boar and to identify haplotypes. To this end, 23 wild boar carcasses shot by hunters during the 2023 hunting season were necropsied and all internal organs were examined. Cysticercus tenuicollis (n = 07) and hydatid cyst (n = 10) isolates were obtained from the examined boars. Species identification of Cysticercus and hydatid cyst isolates was performed by amplification of partial fragments of the cox1 gene. According to BLAST search, all sequences of C. tenuicollis isolates were identified as Taenia hydatigena. Out of the hydatid cyst isolates, seven were classified as Echinococcus granulosus sensu stricto (G1/G3) and one sample was identified as Echinococcus canadensis (G6/G7). All isolates of E. granulosus s.s. (G1/G3) were re-amplified with the NADH dehydrogenase subunit 5 (nad5) in order to distinguish between G1 and G3 genotypes. Based on the sequence analysis, it was found that five of the E. granulosus s.s. isolates were classified as G1, while two were classified as G3. Based on the results of this study, it can be concluded that the G1 genotype is the most prevalent genetic variant among wild boar populations in Bingol province, Türkiye. In this study, a total of five novel haplotypes were identified. A previously unidentified haplotype was revealed through the haplotype analysis of E. canadensis (G6/G7). All isolates in the haplotype network of T. hydatigena were shown to exhibit distinct and geographically specific haplotypes. According to the findings of the study, wild boars include a substantial amount of genetic variety in E. granulosus s.s. And T. hydatigena.

Human cystic echinococcosis: first molecular identification of Echinococcus canadensis G7 in Brazil

Echinococcus granulosus sensu lato (s.l.) is a species complex with the potential to cause cystic echinococcosis (CE). Contact with the feces of domestic dogs (Canis familiaris) fed with raw viscera of intermediate livestock hosts is a risk factor for this infection in the southern region of Brazil. Although the region has been considered endemic to CE for many years, molecular data regarding the species of the complex causing CE in humans are scarce. This study aimed to perform a molecular analysis of the biological fluid from a human liver cyst to investigate the species responsible for CE. Genetic material obtained from the hydatid fluid of a hepatic cyst from a human with CE was subjected to PCR to amplify mitochondrial and nuclear DNA sequences. The phylogenetic analysis confirmed the human infection by Echinococcus canadensis G7 in the state of Paraná, Brazil. This is the first molecular record of E. canadensis G7 infecting a human in Brazil, and it is important to reiterate the risk of human CE caused by this species in South America, as reported by a previous study in Patagonia, Argentina. From the epidemiological point of view, this finding is of great relevance for the southern region of Brazil, since this parasite has previously only been detected in pigs in the state of Rio Grande do Sul, neighboring Paraná. The finding points to the importance of this identification in the molecular epidemiology of E. granulosus s.l., especially in South America.

Echinococcus granulosus Sensu Stricto and Echinococcus multilocularis in a Gray Wolf (Canis lupus) in Turkey: Further Evidence for Increased Risk of Alveolar Echinococcosis in Urban Areas

OBJECTIVE

The aim of this study was to identify Echinococcus species by morphological and molecular means.

METHODS

A dead gray wolf (Canis lupus) was found near Erzurum province and brought to the parasitology laboratory. Sedimentation and counting technique (SCT) and polymerase chain reaction (PCR) analysis were conducted.

RESULTS

The SCT implications indicated that the wolf had a substantial worm burden (62,720 and 49,280 parasites) due to a co-infection of E. granulosus s.l. and E. multilocularis. Genus/species-specific PCR was used to analyze DNA extracted from adult worms and confirmed as E. granulosus s.s. and E. multilocularis, utilizing COI and 12S rRNA gene sequence analysis, respectively.

CONCLUSION

This report presents the first co-detection of E. granulosus s.s. and E. multilocularis in a gray wolf found in an urban area in a highly endemic area for human echinococcosis in northeastern Turkey. The results emphasize that AE is not only a problem of rural areas, but also occurs in urban areas, which may pose a threat to public health. Therefore, surveillance in urban areas is crucial. The need to develop new control strategies for domestic and wildlife in the study area is also highlighted.