Acute visceral cysticercosis by Taenia hydatigena in lambs and treatment with praziquantel

Parasitic findings on threatened pudu deer from Central Chile accounts first genetic characterization of lice parasitizing P. puda in Chile and the first molecular report of Taenia hydatigena metacestodes in this species

Southern pudu (Pudu puda) is a threatened endemic deer of the temperate forests of Chile. In recent years pudu populations rates have decreased mainly due to anthropogenic causes including forest loss and landscape fragmentation. In this context, the parasitic fauna of Chilean pudu has been scarcely investigated. The aim of this study was to determine the parasitic status of rescued pudu n = 13 from its natural habitat in Central Chile (Maule region) during March 2022 and June 2023 by applying morphological, histopathological, and molecular analyses. As result, we report the presence of transmission of parasites from dogs to pudus as showed by the presence of metacestodes of the parasite Taenia hydatigena on omentum, liver, and pleura of pudus during postmortem examinations, being the first molecular report on the presence of this parasite on Chilean pudu. Meanwhile, ectoparasite examinations determined the presence of chewing and sucking lice on pudu exemplars here analysed. Molecular and phylogenetic analysis of lice revealed new insights on Bovicola and Anoplura lice parasitizing P. puda in Chile, equally being the first genetic characterization of lice parasitizing pudu exemplars in Chile. In addition, parasite loads of lice and metacestodes were analysed. However, no statistically significance was observed when comparing environmental and individual traits influence on parasite load variation. Overall, the study area is the northern limit of habitat distribution of this specie in Chile and we here provide novel information on pudu deer parasites, thus making a useful and valuable contribution to the parasitological knowledge on this threatened species.

Acute cysticercosis caused by Cysticercus tenuicollis in lambs

Twelve 30- to 75-day-old mixed breed lambs were examined in an intensive system because of sudden recumbency and death. Clinical examination revealed sudden recumbency, visceral pain, and auscultation of respiratory crackles. Lambs died shortly (between 30 minutes and 3 hours) after the onset of clinical signs. The lambs were necropsied, and after routine parasitology, bacteriology and histopathology procedures, the occurrence of acute cysticercosis caused by Cysticercus tenuicollis was confirmed. The use of the suspect infested feed (newly purchased starter concentrate) was discontinued and other lambs of the flock were treated with praziquantel (15 mg/kg, single dose, orally). After these actions, no new cases were observed. The present study showed the importance of preventive measures against cysticercosis in intensive sheep farming systems which include proper storage of feed, preventing feed and environmental access by potential definitive hosts, and implementing consistent parasite control programs in dogs that are in contact with sheep.

Morphometry and genetic diversity pattern of Cysticercus tenuicollis, an important food-borne taeniid metacestode in goats in Bangladesh

Cysticercus tenuicollis is a larval stage of Taenia hydatigena resulting in cysticercosis, and responsible for enormous economic loses, especially in livestock production. Here, we planned to determine the prevalence and explore genetic variation of C. tenuicollis isolated from goats based on small subunit ribosomal RNA (rrnS) and cytochrome oxidase subunit 1 (cox1). To do this, samples were collected from different slaughter houses of municipal areas such as Bramhapalli slaughterhouse, Jubileeghat slaughterhouse and Mesuabazar slaughterhouse at Mymensingh sadar, and tentatively identified by morphological and morphometrical analysis. To study genetic variation, DNA was extracted from C. tenuicollis, and amplified rrnS and cox1 genes using specific primers, and were sequenced. Among 1372 examined animals, 177 (12.9%) were infected with C. tenuicollis. Cysts were recovered from peritoneum (7.9%), liver (4.4%) and urinary bladder (0.6%) of the infected animals. Females (18.9%) and adults (20.7%) were significantly more susceptible than male (8.8%) and young (9.3%), respectively. Genetic analysis defined 8 distinct rrnS genotypes and 9 unique cox1 haplotypes among 20 C. tenuicollis isolates. The nucleotide diversities were 0.00283 and 0.00434 for rrnS and cox1 genes, respectively. Neighbor joining (NJ) trees of rrnS and cox1 gene were constructed and the studied sequences were clustered with reference sequences of T. hydatigena with strong nodal support (100%). To compare Bangladeshi isolates, a median joining network was constructed with the population from other geographical regions and hosts. This led to a clustering pattern, but the clusters were not built with unique geographical regions or hosts. In conclusion, this is the first study that describes the genetic variation of T. hydatigena population and suggests the existence of host-specific variants. Therefore, it is fundamental to dispose infected viscera, restrict dog movement and proper management of slaughter house for the prevention and control of cysticercosis.

Prevalence and phylogeography of Taenia hydatigena metacestodes from goats of India

The study determined the prevalence and genetic population structure relationships of Cysticercus tenuicollis (Taenia hydatigena metacestode) retrieved from the goats slaughtered in north India. An overall prevalence of 9.62% (59/613) was recorded. Genetic population structure relationships were assessed by targeting partial cytochrome c oxidase subunit 1 mitochondrial gene sequence. Phylogenetic tree analysis revealed that all the present study representative isolates (n = 7) formed a major clade and grouped with T. hydatigena isolates retrieved from sheep, goats, pigs and dogs, originating from China, Iran, Nigeria, Ghana and Poland. However, a single isolate from Himachal Pradesh (isolate 3) formed a subgroup within the clade. The neutrality and diversity indices revealed high values of haplotype diversity [Hd = 0.99695 (0.95238–1.0000)] and low nucleotide diversity (π = 0.49276), which was indicative of demographic expansion and low gene flow, suggesting that Indian T. hydatigena isolates were not genetically differentiated. Tajima's D (−1.26988) and Fu and Li's D statistics values (−0.74556) were negative, demonstrating deviations from neutrality and both propounded recent population expansion or purifying selection. Results highlighted a low genetic diversity of T. hydatigena metacestodes across the geographical range of north India.

Prevalence and genetic variance of Taenia hydatigena in goats and sheep from northern Ghana: Preliminary data on a globally neglected livestock parasite

Cysticercosis caused by the larval stages of Taenia hydatigena has a significant global impact on livestock production, particularly of goats and sheep. Despite this, global data on prevalence and genetic variance of this parasite are still scarce. In Ghana, as in most African countries, numerous anecdotal observations agree that it is widespread and frequent. To obtain baseline data, we screened 251 goats and 248 sheep in northern Ghana (Upper East Region) for T. hydatigena metacestode and molecularly characterized the isolates using the mtDNA cox1 gene sequence. Prevalence was 58.57% in goats and 60.48% in sheep, confirming the abundance of this parasite in the region. Gene sequences revealed high diversity (π 0.00346, hd 0.809) and significant negative Tajima D and Fu's Fs values, a characteristic of a population experiencing an expansion after a recent bottleneck. This is the first account of the genetic structure of T. hydatigena in Ghana, intended as a basis for subsequent studies in the region.

Praziquantel use in aquaculture - Current status and emerging issues

Parasitic diseases are major constraints in fish mariculture. The anthelmintic praziquantel (PZQ) can effectively treat a range of flatworm parasites in a variety of fish species and has potential for broader application than its current use in the global aquaculture industry. In this review we report on PZQ's current use in the aquaculture industry and discuss its efficacy against various flatworm parasites of fish. Routes of PZQ administration are evaluated, along with issues related to palatability, pharmacokinetics and toxicity in fish, while PZQ's effects on non-target species, environmental impacts, and the development of drug-resistance are discussed.

Genotyping of Taenia hydatigena isolated from sheep and goats in KSA based on Cox1 gene

Sheep and goats are among other herbivorous animals that serve as intermediate hosts (containing the larval stage Cysticercus tenuicollis) of Taenia hydatigena tapeworm. This infection can lead to serious complications or cause death. The genetic diversity and epidemiological significance of cysticercosis due to T. hydatigena is poorly understood. We examined 11,651 goats and 23,542 sheep slaughtered at the municipal abattoir in Makkah, for C. tenuicollis infection. The resulted DNA sequences were compared with previously available sequences from different hosts. Phylogenetic analysis and Pairwise nucleotide variations of cox1 gene were performed. Sheep and goats revealed infection rates of (4.95%) and (4.75%) respectively. DNA sequence analysis of all isolates from both sheep and goats showed that the total haplotypes number was 7. T. hydatigena population with high haplotypes diversity values. The nucleotide diversity was low, while Tajima’s D and Fu’s tests were negative (with no statistical significance). The present work will give valuable information regarding the prevalence and implementation of control and prevention measures of C. tenuicollis.

The genome of the thin-necked bladder worm Taenia hydatigena reveals evolutionary strategies for helminth survival

Taenia hydatigena is a widespread gastrointestinal helminth that causes significant health problems in livestock industry. This parasite can survive in a remarkably wide range of intermediate hosts and affects the transmission dynamics of zoonotic parasites. T. hydatigena is therefore of particular interest to researchers interested in studying zoonotic diseases and the evolutionary strategies of parasites. Herein we report a high-quality draft genome for this tapeworm, characterized by some hallmarks (e.g., expanded genome size, wide integrations of viral-like sequences and extensive alternative splicing during development), and specialized adaptations related to its parasitic fitness (e.g., adaptive evolutions for teguments and lipid metabolism). Importantly, in contrast with the evolutionarily close trematodes, which achieve gene diversification associated with immunosuppression by gene family expansions, in T. hydatigena and other cestodes, this is accomplished by alternative splicing and gene loss. This indicates that these two classes have evolved different mechanisms for survival. In addition, molecular targets for diagnosis and intervention were identified to facilitate the development of control interventions. Overall, this work uncovers new strategies by which helminths evolved to interact with their hosts.

Prevalence and risk factors of Taenia hydatigena in dogs, pigs, and cattle in the Central Highlands of Vietnam

Taenia hydatigena is a globally distributed canine tapeworm. The canine tapeworm results in economic impacts for farmers owing to organ condemnation. T. hydatigena utilizes dogs and other carnivores as definitive hosts while swine and ruminants serve as intermediate hosts. T. hydatigena is endemic in Vietnam; however, information on the prevalence and risk factors associated with infection is scarce. This cross-sectional study aims to identify the prevalence of T. hydatigena taeniasis in dogs and T. hydatigena cysticercosis in pigs and cattle. The risk factors associated with taeniasis in dogs were identified using a fixed effects logistic regression model and quantified using population attributable fractions. The prevalence of T. hydatigena taeniasis in dogs and T. hydatigena cysticercosis in pigs and cattle was 10.31% (95% CI 8.21 to 12.84%), 7.60% (95% CI 6.34 to 9.08%), and 11.11% (95% CI 7.63 to 11.81%), respectively; these levels were lower than those reported in other regions of Vietnam. The population attributable fraction of risk factors associated with T. hydatigena taeniasis in dogs for dogs living in proximity of an abattoir, those having access to raw pork or beef viscera, and those living in multi-dog households were 80%, 19%, and 7%, respectively. This current study identified and quantified the risk factors for taeniasis in dogs thus advocating for targeted community intervention programs to break the lifecycle of T. hydatigena in Dak Lak province.

Taenia hydatigena in goat and sheep in Ghana: a cross-sectional abattoir survey in Northern and Upper West Regions

Parasitic infections are a major setback to livestock production in Ghana but the disease situation in many localities is poorly understood. A study to determine the prevalence and distribution of Taenia hydatigena in goats and sheep was carried out in two major municipal abattoirs in Tamale and Wa. A total of 538 goats and 256 sheep were screened for cysts during a cross-sectional survey which revealed a prevalence of 22.34% and 33.96% in goats from Tamale and Wa, respectively, and 22.66% in sheep from Tamale. Infection was common in male and female, young and old animals alike. Animals considered in the study originated from various localities within Northern and Upper West Regions and T. hydatigena infection was thought to be autochthonous, depicting a wide distribution of the cestode infection in small ruminants. Our data represent the importance of T. hydatigena infection in goat and sheep production and provide a base for subsequent epidemiological studies in Ghana.

Molecular characterization of Cysticercus tenuicollis isolates from sheep in the Nile Delta, Egypt and a review on Taenia hydatigena infections worldwide

The predator–prey-transmitted cestode Taenia hydatigena infects a wide range of definitive and intermediate hosts all over the world. Domestic and sylvatic cycles of transmission are considered as well. The parasite has considerable economic importance, particularly in sheep. Here, the molecular characters of T. hydatigena cysticerci in sheep from the Nile Delta, Egypt were investigated for the first time. For this purpose, 200 sheep carcasses and their offal were inspected at the municipal abattoir, Dakahlia governorate, Egypt. Cysticerci of T. hydatigena were collected and molecularly characterized employing the mitochondrial 12S rRNA gene. Cysticerci were found in 42 (21%) sheep, mostly attached to the omenti, mesenteries and livers. After molecular confirmation, nine isolates were sequenced displaying six different haplotypes. Analysis of the T. hydatigena 12S rRNA nucleotide sequences deposited in GenBank revealed 55 haplotypes out of 69 isolates, displaying high haplotype (0.797) and low nucleotide (0.00739) diversities. For the Tajima D neutrality index, a negative value (−2.702) was determined, indicating the population expansion of the parasite. Additionally, global data summarized in this study should be useful to set up effective control strategies against this ubiquitous parasite.

Parasitic cysts in wild boars hunted in Central Italy: The sanitary controls in the wild game meats chain

Seven hundred sixty-five (765) adult wild boars were examined during the 2016/2017 hunting season for the research of parasites. Post mortem inspection was carried out at the slaughterhouse by the Official Veterinarian on the plucks (heart, tongue, lungs, diaphragm, and liver) of the killed animals presented by hunters. Of these, 0.8% (6/765) were positive for Echinococcus granulosus sensu lato (s.l.), and 2.6% (20/765) were positive for the metacestode stage of Taenia hydatigena (Cysticercus tenuicollis), while 0.5% (4/765) animals showed a mixed infection (Echinococcus granulosus s.l. and Taenia hydatigena). Sixty-three (63) cystic lesions were found. Of these 25,4% (16/63) were caused by Echinococcus granulosus s.l. and 74,6% (47/63) were caused by Cysticercus tenuicollis. The more involved organs were liver and lungs, in a less extension omentum and diaphragm. Parasitological analyses showed an overall prevalence of 3.9% for metacestodes in the hunted animals examined (Paoletti et al., 2018). Hydatids were molecularly characterized as E. granulosus sensu stricto. Trichinella spp. examination results showed no evidences of parasitic cysts. The products of hunting used for own consumption and direct sale to the final consumer or retailer, according to Regulation (EC) No 853/2004, lack of overall control by the Competent Authority. This is a critical point in the food chain of the game meat. The data obtained show the importance of the post mortem inspection and the central role of the Competent Authority to ensure not only the food safety of game meat but also to collect data for extensive epidemiological investigations on live-stocks wildlife settings having a direct impact on public health.

PCR-RFLP assay confirms the existence of different mitochondrial lineages of Taenia hydatigena including a possible geographically restricted group

Taenia hydatigena is a widespread tapeworm of canids (primarily dogs) that causes cysticercosis in ruminants (domestic and wild) and manifests as depression and weakness secondary to various hepatic damages and sometimes mortality in young animals, although, commonly encountered cases are asymptomatic. In most taeniids, genetic polymorphism has been found to impact host preferences, distribution, disease epidemiology and management. Recently, we identified two main mitochondrial lineages of T. hydatigena in China, and here, we examined the mitochondrial nad4-nad5 genes of T. hydatigena from China, Nigeria, Pakistan and Sudan to assess the intraspecies variation of isolates from these countries and also the distribution of the distinct mitochondrial groups. In addition to China, haplogroup B variant was found in Pakistan, while haplogroup A demonstrated a widespread distribution. We then designed a PCR-restriction fragment length polymorphism (PCR-RFLP) assay using XmiI (AccI) and RsaI (AfaI) restriction enzymes to differentiate members of both haplogroups. This result provides more molecular evidence supporting the existence of distinct mitochondrial variants of T. hydatigena. The epidemiological significance of these different mitochondrial groups remains to be explored further. The current PCR-RFLP assay offers a useful molecular approach for investigating the genetic population structure of T. hydatigena in enzootic regions and in identifying/discriminating the different mitochondrial groups (haplogroups A and B).

In-silico Analysis of Mt-CO1 Gene of Taenia Hydatigena Sheep Isolates

Taenia hydatigena is a tapeworm that affects herbivores in different regions of the world. Cysticercus tenuicollis (larvae of T. hydatigena), is prevalent in ruminants and pigs. In the current study, phylogenetic analysis of the published mt-CO1 gene of C. tenuicollis sheep isolates was analyzed using in-silico method and vertical and horizontal transmission at the global level by using a meta-analysis approach. A total of 82 mt-CO1 nucleotide sequences (339 bp) of C. tenuicollis sheep isolates from the NCBI database (Italy -Sardinia-, Iran, Palestine, Iraq, Finland, India and China) were used to investigate haplotype and genetic relationships. Tajima's D (-2,2984) value was negative for the mt-CO1 sequences signifying the population expansion and/or purifying selection. The highly negative Fu's Fs (-60,528) values determined for the sequences reflecting the existence of uncommon haplotypes. The mt-CO1 of C. tenuicollis haplotype network had 47 haplotypes arranged within a star-like configuration with a main haplotype, which encompassed 25.6 % of the total isolates. In the mt-CO1 haplotype network analyzed, there were 80.5 % unique single haplotype and highest ratio was observed in C. tenuicollis from sheep originating from Iran, followed by Sardinia, Palestine and Finland. If the current condition continues, genetic differences in T. hydatigena will be able to rise, and possible new strains and/or genotypes that may influence the host adaptation and life cycle of the parasite may emerge.

A new molecular nomenclature for Taenia hydatigena: mitochondrial DNA sequences reveal sufficient diversity suggesting the assignment of major haplotype divisions

Cysticercosis caused by the metacestode larval stage of Taenia hydatigena formerly referred to as Cysticercus tenuicollis is a disease of veterinary importance that constitutes a significant threat to livestock production worldwide, especially in endemic regions due to condemnation of visceral organs and mortality rate of infected young animals. While the genetic diversity among parasites is found to be potentially useful in many areas of research including molecular diagnostics, epidemiology and control, that of T. hydatigena across the globe remains poorly understood. In this study, analysis of the mitochondrial DNA (mtDNA) of adult worms and larval stages of T. hydatigena isolated from dogs, sheep and a wild boar in China showed that the population structure consists of two major haplogroups with very high nucleotide substitutions involving synonymous and non-synonymous changes. Compared with other cestodes such as Echinococcus spp., the genetic variation observed between the haplogroups is sufficient for the assignment of major haplotype or genotype division as both groups showed a total of 166 point-mutation differences between the 12 mitochondrial protein-coding gene sequences. Preliminary analysis of a nuclear protein-coding gene (pepck) did not reveal any peculiar changes between both groups which suggests that these variants may only differ in their mitochondrial makeup.

Molecular Characterization and Phylogeny of Taenia hydatigena and Echinococcus granulosus from Iranian Sheep and Cattle Based on COX1 Gene

Hydatid cyst, the larval stage of Echinococcus granulosus, and Cysticercus tenuicollis, the larval stage of Taenia hydatigena, are prevalent in domestic, livestock, and wild ruminants. The main goal of this research was to identify the isolates of E. granulosus and C. tenuicollis by partial sequencing with PCR amplification of the cytochrome C oxidase 1 (COX1) gene. During a routine veterinary inspection at a Chabahar city slaughterhouse, two samples of hydatid cysts from sheep's liver and cattle's lung and two samples of C. tenuicollis from sheep's liver were collected. After DNA extraction, the fragment of the COX1 gene was amplified by the PCR method. Sample sequences were modified and synchronized by Chromas and CLC genomic workbench 11 software. Sequence analysis was carried out by BLAST algorithms and GenBank databases. Phylogenetic trees were performed using MEGA 7 software and the neighbor-joining and maximum likelihood method for T. hydatigena and E. granulousus. The result indicated that the main genotype of parasites and the amplified fragment size were G1 and approximately 455 bp, respectively. The analysis of phylogenetic trees based on nucleic acid for four samples showed that there was a common ancestor. However, the shift in nucleotides in the two isolates in E. granulosus and the two isolates of T. hydatigena were non-synonymous type and synonymous type, respectively. The present study showed that the dominant genotype in all isolates was G1 and this report was similar to other studies in Iran and the world. Also, the partial COX1 gene sequence was matched with T. hydatigena.

Αcute visceral cysticercosis caused by Taenia hydatigena in lambs: ultrasonographic findings

Background

Cysticercosis caused by cysticercus tenuicollis is a metacestode infection that affects several species of ungulates. It is caused by the larval stage of Taenia hydatigena, an intestinal tapeworm in dogs and wild canids. In the intermediate host, the mature cysticerci are usually found in the omentum, mesentery, and peritoneum, and less frequently in the pleura and pericardium. The migrating larvae can be found mostly in the liver parenchyma causing traumatic hepatitis in young animals. Most infections are chronic and asymptomatic, and are diagnosed at the abattoir. The acute form of infection is unusual in sheep and reports of death in lambs are rare.

Methods

In March 2018, fifteen female lambs presented anorexia, weakness, lethargy, and death secondary to acute visceral cysticercosis. Twelve of them underwent hepatic ultrasonography. Examinations were performed on standing or left lateral recumbent animals.

Results

Livers of affected animals presented rounded margins and a thickened, irregular and hyperechoic surface. Hepatic parenchyma appeared to be wholly or partially affected by lesions characterized by heterogeneous areas crossed by numerous, irregular, anechoic tracts ranging from 1 to 2 cm in length and 0.1 to 0.2 cm in width. Superficial and intraparenchymal cystic structures were also visualized. The presence of lesions was confirmed by anatomopathological examination, and T. hydatigena cysticerci was identified by morphological and molecular characterization of isolates.

Conclusions

Our results highlighted that hepatic ultrasonography is effective for an intra-vitam diagnosis of acute cysticercosis in lambs.

Taenia hydatigena cysticercosis in wild boar (Sus scrofa) from southern Italy: an epidemiological and molecular survey

Taenia hydatigena cysticercosis is a widespread parasitic disease of wild and domestic animals. In Europe, the increase in wild boar population may potentially contribute to the spread of this parasitic infection. To determine the occurrence of cysticerci (metacestodes) in wild boar population from southern Italy, carcasses were inspected during three hunting seasons (2016-2018). Out of 3363 wild boar examined, 229 (6.8%) harboured cysticerci with 188 (82.1%) infected by a single cyst, vs 41 (17.9%) boars having more than one. Most of the positive animals (187; 81.7%) showed cysts on the liver, whereas a multiple localization of cysticerci was reported in 10 (4.4%) wild boar. The total number of cysts retrieved from positive animals was 301 (average 1.3). Molecular analysis revealed the occurrence of a common haplotype (Hap 8) shared between wild boar and domestic animals. Our findings suggest the presence of a T. hydatigena semi-domestic life cycle in which wild boar may play an important role, due to a large number of offal available to hunting dogs, wolves and foxes during hunting seasons. Hunters may be players in the management of wildlife species to control and prevent the circulation of parasitic diseases.

Preliminary information on the prevalence and molecular description of Taenia hydatigena isolates in Pakistan based on mitochondrial cox1 gene

Taenia hydatigena is a cestode of veterinary importance. Infection with the metacestode larval stage results in cysticercosis, which poses a serious challenge to the livestock industry worldwide. Globally, there are numerous reports on cysticercosis caused by T. hydatigena in sheep and goat but a lack of data on the prevalence and genetic diversity exists for Pakistan. We designed this study to provide an insight into the disease status as well as investigate the genetic variation among the recovered isolates based on the mitochondrial cox1 gene. In this study, we examined small ruminants (sheep and goats) slaughtered in Faisalabad in eastern Punjab province of Pakistan for T. hydatigena metacestodes and described the population structure and genetic variation using the cytochrome c oxidase subunit 1 (cox1) mitochondrial gene. Overall, a prevalence of 4.40% (goat =4.67% sheep = 4.07%) from a total of 2225 small ruminant carcasses (sheep = 983, goats = 1242) was observed. Based on the NCBI BLAST search and Bayesian phylogeny, the identity of all isolates was confirmed via their nucleotide sequences. The diversity indices indicated a high haplotype and a low nucleotide diversity with 43 haplotypes from 98 isolates. The results also show the existence of unique haplotypes of T. hydatigena in Pakistan as demonstrated by the significant negative values of Tajima's D and Fu's Fs neutrality test suggesting a recent population expansion. The median-joining network of the partial cox1 sequence dataset showed the existence of two main haplotypes detected in both sheep and goat populations. This study shows that the prevalence of cycticercosis due to T. hydatigena is below 5% in sheep and goats in Faisalabad, Punjab, Pakistan. The molecular analysis of the partial cox1 gene also indicates a high degree of genetic variation with the existence of rare haplotypes. These findings represent a preliminary report on the prevalence and genetic variation of T. hydatigena in Pakistan and serve as baseline information for future studies on the prevalence and population structure of T. hydatigena in the country.

Diversity of Taenia and Hydatigera (Cestoda: Taeniidae) in domestic dogs in Kenya

Taenia species of domestic dogs can cause cysticercosis and coenurosis in a wide range of intermediate hosts including humans. Most taeniids of dogs are globally distributed, but some wildlife-transmitted species can be specific for certain regions. Generally, little information exists on the species composition and frequency in most regions of the world, which impairs risk assessment and control strategies. This study determined the range of taeniid species in dogs in four widely spaced areas of Kenya by genetic identification of eggs in faeces collected from the environment. Individual taeniid eggs were characterised by nested polymerase chain reaction of NADH dehydrogenase subunit 1 and cytochrome C oxidase 1 genes, restriction fragment length polymorphism and partial sequencing. Overall 79/1621 (4.9%) faecal samples contained eggs of Taenia or Hydatigera (8.0% in Turkana, 4.8% in Isiolo, 3.8% in Maasai Mara and 1.3% in Meru). Taenia hydatigena and T. multiceps were the most frequent, found in 36 and 15 samples, respectively. Other eggs found in the faeces belonged to T. serialis (sensu lato), T. madoquae (the first record in domestic dogs), T. ovis, T. saginata and Hydatigera taeniaeformis. Polymorphism of nad1 sequences revealed 22 and 8 haplotypes of T. hydatigena and T. multiceps, respectively. The results show the involvement of dogs in both domestic and sylvatic transmission cycles. In addition to the species range, this study provides data on the intraspecific diversity of T. hydatigena and T. multiceps in Kenya, which will serve as baseline information for further studies into cysticercosis and coenurosis in livestock and humans in the region.

Infection rate and biochemical characterization of Cysticercus tenuicollis from sheep in Minoufiya governorate, Egypt

Cysticercus tenuicollis, the larval stage of Taenia hydatigenia, infects sheep and causes economic losses due to condemnation of infected organs. This study was designed to report the infection rate, risk factors, biochemical, and molecular characterization of Cysticercus tenuicollis in sheep from Ashmoun, Minoufiya, Egypt. The infection rate was 18%. The age was a risk factor for infection where there was a significant difference in infection rate between sheep more than 3 years and sheep under 3 years of age. There was no significant difference between infection in male and female groups. The liver had the highest organ distribution followed by omentum. Biochemical analysis of the cyst fluid showed some variations in the levels of ALT, AST, triglycerides, cholesterol, total protein, urea nitrogen, calcium, sodium, chromium, potassium than the levels identified in Algeria, Iraq, and Iran. PCR and sequence analysis of cox1 and ssrRNA showed that the sequences from Minoufiya, Egypt were highly identical to the related ones from several countries and confirmed the cyst is Cysticercus tenuicollis. This study reported the infection rate, risk factors, biochemical analysis, and molecular characterization of Cysticercus tenuicollis in sheep from Minoufiya, Egypt.

Morphometric, genetic diversity and phylogenetic analysis of Taenia hydatigena (Pallas, 1766) larval stage in Iranian livestock

Cysticercus tenuicollis as metacestode of Taenia hydatigena is the most prevalent taeniid species in livestock. Eighty-eight C. tenuicollis samples were collected from sheep (n = 44) and goats (n = 44) of the northern Iran from 2015 to 2016. The isolated parasites were characterized by morphometric keys. The DNA of the larval stage was extracted, amplified and sequenced targeting mitochondrial 12S rRNA and Cox 1 markers. A significant difference in larval rostellar hook length was observed in 12S rRNA haplotypes. Analysis of molecular variance of 12S rRNA indicated a moderate genetic diversity in the C. tenuicollis isolates. The pairwise sequence distance of C. tenuicollis showed an intra-species diversity of 0.3-0.5% and identity of 99.5-100%. Using the 12S rRNA sequence data we found a moderate genetic difference (Fst; 0.05421) in C. tenucollis isolates collected from livestock of the northern and southeastern regions of Iran. We concluded that the genetic variants of C. tenuicollis are being undoubtedly distributing mostly in different parts of Iran. Further studies with a larger number of T. hydatigena isolates collected from various intermediate and definitive hosts are needed to study this evolutionary assumption and also to determine the apparent genetic differences observed in the studied regions.

Cysticidal activity of praziquantel-mebendazole combination: In vitro and in vivo studies

The current pharmacological treatment of neurocysticercosis is based on two drugs, praziquantel (PZQ) and albendazole; however, suboptimal efficacy has been documented. Previous studies, have documented the activity of mebendazole (MBZ) against Taenia sp, and its capability to cross the blood-brain barrier. Considering this information and in an effort to search other options for neurocysticercosis treatment, the present study was designed to assess the in vitro and in vivo activity of the PZQ-MBZ combination against Taenia crassiceps metacestodes. For the in vitro studies T. crassiceps cysticerci (ORF strain) were used and the analysis of the combinations was performed using the Surface of Synergistic Interaction (SSI). For the in vivo evaluation the experimental infection model of T. crassiceps ORF in Balb-C mice was used. In vitro results showed that the combination of PZQ 121.6 nM-MBZ 5.1 nM exhibited the highest synergic cysticidal effect. In vivo, the PZQ-MBZ combination (25 mg/kg - 50 mg/kg, respectively) was more effective than each drug alone. The findings indicate that PZQ in combination with MBZ could be a promising alternative for the treatment of neurocysticercosis. Complementary studies are required to confirm its clinical applicability.

Molecular identification of Taenia hydatigena and Mesocestoides species based on copro-DNA analysis of wild carnivores in Mongolia

Cyclophyllidean tapeworms obligatorily parasitize numerous mammalian species, including herbivores, domestic animals and humans, of which, the genera Taenia and Mesocestoides are well characterized. However, little is known about these parasitic infections in wild animals. This study aims to investigate the prevalence and distribution of Taenia sp. and Mesocestoides sp. in wild carnivores in Mongolia by identifying tapeworm species based on mtDNA analysis. The field survey was carried out in 2012–2013 in 19 provinces located in different ecological regions. A total of 405 fecal samples from wild carnivores were collected. Specific DNA markers in fecal samples was detected via copro-DNA analysis and tapeworm species were identified by DNA sequencing. From 27.7% (112/405) of samples, cox1 and 12S rRNA genes of tapeworms were amplified. Further, Taenia hydatigena (50.0%, 56/112) and two Mesocestoides species, including Mesocestoides sp.-1 (36.6%, 41/112) and Mesocestoides sp.-2 (13.4%, 15/112) were identified by DNA sequencing. The prevalence of T. hydatigena was 19.9% (27/136), 13.8% (23/167), 4.8% (3/62), and 7.5% (3/40) in wolves, red foxes, corsac foxes, and snow leopards, respectively. The prevalence of Mesocestoides sp.-1 was 14.7% (20/136), 9% (15/167), 9.7% (6/62) in wolves, red foxes, and corsac foxes, while the prevalence of Mesocestoides sp.-2 was 4.4% (6/136), 1.8% (3/167), 3.2% (2/62), and 10.0% (4/40) in wolves, red foxes, corsac foxes, and snow leopards, respectively. T. hydatigena was found throughout all ecological regions, while Mesocestoides sp.-1 was in the mountain taiga, forest-steppe, steppe, desert-steppe, and desert, and Mesocestoides sp.-2 in the alpine, forest-steppe, steppe, and desert-steppe ecoregions. This study revealed the prevalence and distribution of cyclophyllidean tapeworms in wild carnivores in Mongolia; while also confirming that wolves, red foxes, corsac foxes, and snow leopards serve as definitive hosts for unidentified Mesocestoides species.

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Taenia hydatigena and two Mesocestoides species were first identified by copro-DNA analysis in wild carnivores in Mongolia.

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The persistent infections by T. hydatigena and Mesocestoides species in these animals were shown.

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T. hydatigena was detected in all ecoregions in Mongolia.

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Mesocestoides sp.-1 was found in wild carnivores inhabiting in all ecoregion unless in the alpine, and Mesocestoides sp.-2 in the alpine, forest-steppe, steppe, and desert-steppe ecoregions.

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Wolf, red fox, corsac fox, and snow leopard were confirmed as definitive hosts for Mesocestoides species.

Massive Taenia hydatigena Cysticercosis in a Wild Boar (Sus scrofa) from Italy

PURPOSE

Taenia hydatigena cysticercosis, due to Cysticercus tenuicollis, is a parasitic disease infecting domestic and wild animals worldwide causing economic and productive losses. Nonetheless, little attention has been paid to the role of the wild ungulates in the epidemiology of this disease. In the last years, the increasing population of wild boars in Europe has raised the attention of researchers on their role in the spreading of several infections, including those caused by cestodes. Herein, we report the description of a massive infection due to T. hydatigena cysticercosis in a wild boar from southern Italy.

METHODS

An adult female boar was examined during the hunting season 2018 within the regional project "Piano Emergenza Cinghiali in Campania". A complete necropsy was performed on the boar carcass and all viscera were examined to determine number and location of the cysts. Morphological and molecular analyses of the cysts were performed to confirm the C. tenuicollis identity.

RESULTS

The boar examined has revealed an impressive massive infection with 265 cysts. Measurements of the large and small larval hooks showed a mean of length as 200.3 µm and 136.8 µm, respectively. Molecular analysis of Cox1 and ND1 mitochondrial genes confirmed the C. tenuicollis identity.

CONCLUSIONS

Our findings suggest that wild boar could be involved in the epidemiology of T. hydatigena, due to the significant amount of boar raw offal available to definitive hosts (i.e., hunting dogs, foxes and wolves), during the hunting seasons.

Infestation of small ruminants by the metacestode stage of Taenia hydatigena in slaughterhouse, North East Tunisia

Background

Cysticercus tenuicollis (larvae of Taenia hydatigena) is a frequent cosmopolitan endoparasite of ruminants. The infestation by this parasite is underestimated since it is neither zoonotic nor inducing high economic losses in the sheep sector.

Methods

This study aimed at estimating different parasitological indicators, Cysticercus tenuicollis infestation in small ruminants using a slaughterhouse‐based survey in Northeast Tunisia. A total number of 3,692 sheep and 78 goats were examined in the slaughterhouse of Menzel Temime.

Results

The overall prevalence was estimated to be 2.8 (106/3692) and 8.9% (7/78) in sheep and goats, respectively. The abundance in these two species was 0.24 and 0.05 and the intensity 1.97 and 2.85, respectively. In goats, all the cysts were found in the mesentery, whilst, in sheep, the majority were in mesentery (96%) but also on the liver in 2% of the cases and in both organs (2%). There were only cysts with aqueous liquid with predominantly middle‐sized cysts (1 to 3 cm) corresponding to 63.15 and 70.34% in sheep and goats, respectively.

Conclusion

Since, in small ruminants, the infestation by C. tenuicollis indicators are not high, low cost control measures should be implemented to eliminate this parasite in Northeast Tunisia.

First molecular description, phylogeny and genetic variation of Taenia hydatigena from Nigerian sheep and goats based on three mitochondrial genes

BACKGROUND

Cysticercosis caused by the metacestode larval stage of Taenia hydatigena is a disease of veterinary and economic importance. A considerable level of genetic variation among isolates of different intermediate hosts and locations has been documented. Generally, data on the genetic population structure of T. hydatigena is scanty and lacking in Nigeria. Meanwhile, similar findings in other cestodes like Echinococcus spp. have been found to be of epidemiological importance. Our aim, therefore, was to characterize and compare the genetic diversity of T. hydatigena population in Nigeria based on three mitochondrial DNA markers as well as to assess the phylogenetic relationship with populations from other geographical regions.

METHODS

In the present study, we described the genetic variation and diversity of T. hydatigena isolates from Nigerian sheep and goats using three full-length mitochondrial genes: the cytochrome c oxidase subunit 1 (cox1), NADH dehydrogenase subunit 1 (nad1), and NADH dehydrogenase subunit 5 (nad5).

RESULTS

The median-joining network of concatenated cox1-nad1-nad5 sequences indicated that T. hydatigena metacestodes of sheep origin were genetically distinct from those obtained in goats and this was supported by high F_ST values of nad1, cox1, and concatenated cox1-nad1-nad5 sequences. Genetic variation was also found to be higher in isolates from goats than from sheep.

CONCLUSIONS

To the best of our knowledge, the present study described the genetic variation of T. hydatigena population for the first time in Nigeria using full-length mitochondrial genes and suggests the existence of host-specific variants. The population indices of the different DNA markers suggest that analysis of long mitochondrial DNA fragments may provide more information on the molecular ecology of T. hydatigena. We recommend that future studies employ long mitochondrial DNA sequence in order to provide reliable data that would explain the extent of genetic variation in different hosts/locations and the biological and epidemiological significance.

Epidemiological survey on cystic echinococcosis in wild boar from Central Italy

Despite the wide distribution of wild boar populations in Italy and the increase of its diffusion in urbanized areas, only one case report has described the occurrence of Echinococcus granulosus s.l. in a wild boar from Marche (Central Italy). The present study investigated the presence of E. granulosus sensu lato with an epidemiological survey on wild boars from central Italy that had been killed during hunting season. Seven hundred sixty-five (765) adult wild boars were examined during the 2016-2017 hunting season. Of these animals, 1.0% (8/765) were positive to E. granulosus s.l. with a fertility of 0.3% (2/765), and 2.9% animals (22/765) were positive for the metacestode stage of Taenia hydatigena (Cysticercus tenuicollis), while 0.5% (4/765) showed mixed infection (E. granulosus s.l. + T. hydatigena). Sixteen hydatids were found, of which 12.5% were fertile, 37.5% were sterile, 31.3% were caseous, and 18.8% were calcified. Eight hydatids (two fertile and six sterile cysts) were molecularly characterized by analysis of the mitochondrial gene, cytochrome c oxidase subunit 1 (cox1), and the NADH dehydrogenase subunit 1 (ND1). Hydatids found in wild boars were characterized as E. granulosus sensu stricto (G1 genotype). The present survey represents the first epidemiological study on cystic echinococcosis in wild boar in Italy which highlights the need for more extensive epidemiological investigations to determine the causal factors, economic impact, and public health importance of the disease in this livestock-wildlife setting.

Proteomic analysis of Taenia hydatigena metacestode by high performance liquid chromatography-coupled tandem mass spectrometry (LC-MS/MS)

This study determined the profile of proteins in T. hydatigena metacestode by LC-MS/MS. Furthermore, comparison of 6 tapeworms revealed the presence of Taenia-specific filamin proteins and Echinococcus-specific UGPase proteins. These data provide clues for better understanding of T. hydatigena biological characteristics, which provides a new choice for screening of new diagnostic antigens for differential diagnosis of diseases by coinfections of various tapeworm metacestodes.

Population expansion and individual age affect endoparasite richness and diversity in a recolonising large carnivore population

The recent recolonisation of the Central European lowland (CEL) by the grey wolf (Canis lupus) provides an excellent opportunity to study the effect of founder events on endoparasite diversity. Which role do prey and predator populations play in the re-establishment of endoparasite life cycles? Which intrinsic and extrinsic factors control individual endoparasite diversity in an expanding host population? In 53 individually known CEL wolves sampled in Germany, we revealed a community of four cestode, eight nematode, one trematode and 12 potential Sarcocystis species through molecular genetic techniques. Infections with zoonotic Echinococcus multilocularis, Trichinella britovi and T. spiralis occurred as single cases. Per capita endoparasite species richness and diversity significantly increased with population size and changed with age, whereas sex, microsatellite heterozygosity, and geographic origin had no effect. Tapeworm abundance (Taenia spp.) was significantly higher in immigrants than natives. Metacestode prevalence was slightly higher in ungulates from wolf territories than from control areas elsewhere. Even though alternative canid definitive hosts might also play a role within the investigated parasite life cycles, our findings indicate that (1) immigrated wolves increase parasite diversity in German packs, and (2) prevalence of wolf-associated parasites had declined during wolf absence and has now risen during recolonisation.

Prevalence and risk factors for Cysticercus tenuicollis in goats and sheep in Paraíba, northeastern Brazil

Abstract This study aimed to determine the prevalence and risk factors for C. tenuicollis among goats and sheep in slaughterhouses in Paraíba. 390 animals (195 goats and 195 sheep) in the municipalities of Patos and Esperança, Paraíba, Brazil, were inspected between February and May 2014. The prevalence of C. tenuicollis was 39% (76/195) in goats and 17.4% (34/195) in sheep. In both species, most of the cysticerci vesicles were located at the omentum and mesentery. The only risk factor found was extensive sheep farming. It can be concluded that C. tenuicollis is highly prevalent in small ruminants in Paraíba, being more prevalent in goats than in sheep. Extensively-reared sheep were twice as likely to develop infection by this parasite.

Epidemiological updates and economic losses due to Taenia hydatigena in sheep from Sardinia, Italy

The aim of this study was to investigate the epidemiology and transmission of Taenia hydatigena in sheep and dogs from Sardinia and the economic estimation of losses due to this metacestodosis in lambs. A total of 7781 Sarda breed lambs were examined at abattoirs for the detection of Cysticercus tenuicollis or necrotic-haemorrhagic tracks of their migration. Morphological and molecular identification of parasites was carried out. Individual faecal samples from 300 dogs were examined for copromicroscopic investigations and coproELISA assay. An overall prevalence of 14.6% for T. hydatigena cysticercosis was found in the examined lambs. In total, 10,807 parasitary tracks were found, with an abundance of 1.39 and an average intensity of 9.52. The molecular analysis of the isolates showed an overall pairwise nucleotide divergence for the CO1 and ND1 was of 0-3.1 and 0-3.3%, respectively. Low intra- and interspecific variation was recorded for C. tenuicollis isolates used in this study which suggested the absence of differentiation. Microscopic examination of dog faeces showed a total prevalence of 31.3% for endoparasites in the examined samples (94/300). Taeniid eggs were found in 8.3% of the dogs. The results of the monoclonal antibody ATH4 ELISA test showed a prevalence of 11% (33/300) for T. hydatigena coproantigens. The total economic costs related to cysticercosis amounted to almost € 330,000. The prevalence of C. tenuicollis in 14.6% of 30-40-day-old lambs highlights the high parasitic pressure by T. hydatigena in the territory of Sardinia, Italy.