Morphological and molecular characterization of bovine coenurosis in Sardinia, Italy

Very low frequency waves as selective probe for Cysticercus tenuicollis, Hydatid cyst and Coenurus cerebralis bio-analysis using single cell-signal recording

Comparative electric behavior of Cysticercus tenuicollis, Hydatid cyst and Coenurus cerebralis at the Very Low Frequency (VLF) region has been studied in detail. This investigation could be significant, because of the economic and public health importance of these parasitic infections in domestic animals. In this report, a single cell signal recording technique has been adopted for comparison using a stainless steel (type: 316, diameter: ~ 300 µm, height: 2.00 cm) two identical electrode system, implanted on the surface of the tested cysts with inter electrode distance of 0.50 cm at a ~ 6.0 giga ohm (GΩ) sealed condition (based on the situation of the implanted electrode system). This process was achieved based on applying electrical interaction between the cysts and the VLF electrical signal. Relative to the measured time domain signal (Current-time diagram), the frequency domain (Current-frequency diagram) was estimated via applying a "Discrete Fast Fourier Transform" (DFFT) algorithm at a fixed time interval (5.0 min). Factors, having important influence on the sensitivity of the detection system including the type (waveform) of different alternating-current (AC) triggering stimulus signals (such as direct current, square wave, triangular, sin (t), etc.), the amplitude, as well as the frequency were optimized automatically through a written "Visual Basic 6" program by one-factor-at-a-time method. Direct applying this AC triggering VLF voltage to the cysts resulted in tracing an AC electrical current vs. time that considered as the time domain wave. However, this electrical current was decayed rapidly versus time during maximum 30.0 s time scale. Applying the DFFT algorithm to the measured time domain, resulted in accessing to the frequency domain at the selected frequency range between 2 and 5 kHz that was considered as the selected frequency for the selective differentiation of C. tenuicollis, Hydatid cyst and C. cerebralis. The related probable mechanism of this process may be attributed to the correlation between the triggering potential and the cyst's electrical surface charge (Zeta potential) as the current source under similar conditions. The results of this study may help to introduce a new detection system for in vivo recognition of the cysts in future.

Global epidemiology and molecular biology of Taenia multiceps: a comparative meta-analysis and in silico analysis study

In the present study, all published data on the epidemiology and molecular characters of Taenia multiceps were systematically collected from relevant databases (e.g. PubMed, Scopus, National Center for Biotechnology Information), and combined in various statistical and genetic analyses as a contribution to a better understanding of the epidemiology of this ubiquitous taeniid worldwide. While 5.8% of the key hosts (dogs) from various countries had T. multiceps, grey wolves displayed the highest prevalence (21.6%) among the definitive hosts. Small ruminants are the main intermediate hosts and carry the coenuri in various locations, but most commonly in the central nervous system (CNS). Cerebral coenuri were confirmed in 53% of sheep exhibiting neurological symptoms, and infected animals often had only a single coenurus in the brain. Sheep had a higher prevalence (8.8%) of CNS coenuri than goats (5.8%); however, extra-CNS coenuri were detected more frequently in goats than in sheep. In either case, the difference between sheep and goats was statistically insignificant. Analysis of 233 partial cytochrome oxidase subunit I nucleotide sections for T. multiceps revealed high haplotype and low nucleotide diversities. Fifty-one haplotypes were detected circulating in 6 geographic populations. China, Iran and Turkey had 2 major haplotypes, whereas Italy and Egypt shared 3. Haplotypes from Greece circulate worldwide, and displayed similar gene flow values when compared with the other populations. There were no distinct patterns for haplotype distribution in relation to the infected hosts or coenuri locations. The existence of genetic variants in T. multiceps was highlighted, but needs further studies.

Taenia multiceps coenurosis: a review

Taenia multiceps is a taeniid cestode that inhabits the small intestines of both wild and domestic carnivores. The larval stage, Coenurus cerebralis, is typically found in the central nervous system (CNS) of a wide range of livestock and, to a lesser extent, in the extra-cerebral tissues of sheep and goats. This review covers all aspects of the life cycle of T. multiceps and its epidemiology, molecular characterization, pathogenesis, diagnosis, therapy, control and zoonotic potential. Coenurosis caused by the larval stage of T. multiceps has a worldwide distribution and is often fatal in intermediate hosts, which can result in substantial economic losses in livestock farming. Molecular characterization using the mitochondrial genes cytochrome c oxidase subunit 1 and nicotinamide adenine dinucleotide dehydrogenase subunit 1 of different T. multiceps populations has revealed significant genetic variation and the presence of three major haplotypes. The disease mostly affects young sheep and is referred to as either acute or chronic coenurosis. Acute coenurosis occurs as a result of oncospheres migrating through the CNS, while chronic coenurosis occurs as a consequence of the coenurus maturing, which causes displacement and pressure atrophy of brain tissue. Non-cerebral coenurosis has been most commonly reported in goats. The best diagnostic method for cerebral coenurosis involves the interpretation of clinical signs with accurate localization of the cyst using diagnostic imaging techniques. A vaccine based on recombinant oncosphere antigens has proved to be an effective tool against T. multiceps infection in sheep. Additionally, use of anthelmintics during the parasite's migration stages reduces the development of cysts in the sheep brain. Surgery is considered the most effective method for the treatment of cerebral coenurosis in small ruminants, but is often not carried out because of the limited finances of many sheep and goat breeders. However, coenurosis can also be controlled effectively through preventative measures, such as anthelmintic treatment of dogs and the proper disposal of intermediate host carcasses. The parasite is also zoonotic, and cases of coenurosis have been reported in humans with coenuri located in the brain, spinal cord and eyes.

Comparative Transcriptome Analyses of the Developmental Stages of Taenia multiceps

Cerebral coenurosis, caused by the larvae of Taenia multiceps (Coenurus cerebralis), is a fatal central nervous system disease in sheep and other herbivores and occasionally humans. Comparative transcriptomic profiles of the developmental stages of the parasite remain unknown. In this study, RNA sequencing was used to determine the transcriptome profiles of different stages of the life cycle of T. multiceps, including Oncosphere, Coenurus cerebralis (Pro with Cyst), and Adult (Adu), as well as scolex-neck proglottids (Snp), immature–mature proglottids (Imp), and gravid proglottids (Grp) of the adult stage. A total of 42.6 Gb (average 6.1 Gb) Illumina pair-end reads with a 125-bp read length were generated for seven samples. The total number of differentially expressed genes (DEGs) in the various life stages ranged from 2,577 to 3,879; however, for the tissues of the adult worm, the range was from 1,229 to 1,939. Kyoto Encyclopedia of Genes and Genomes analysis showed that the DEGs mainly participated in cellular and metabolic processes, binding and catalytic activity, genetic information processing, and environmental information processing. In addition, a large number of genes related to development and parasite–host interaction were identified. Quantitative reverse transcription-polymerase chain reaction confirmed that the levels of 28 selected DEGs were consistent with those determined using RNA sequencing. The present study provides insights into the mechanisms of the development and parasitic life of T. multiceps.

Are current practices of yak herdsmen adequate to combat Coenurosis in Laya Bhutan?

Background

Coenurosis, known commonly as gid, is caused by a tapeworm Taenia multiceps. It is a disease of small ruminants globally but also occurs in large ruminants, especially in yak in the Himalaya. Gid is a pathological condition in young yaks, mostly below 3 years of age. The infected animal displays a circling movement with the head tilting towards the location of the cyst of a tapeworm on the cerebral surface of the brain.

Objective

We conducted a study with the primary aim to gain an insight into yak herdsmen's practices to manage Coenurosis in the Laya administrative block of Bhutan.

Methods

All seven villages of Laya were included for sampling. Seventy‐five out of 182 households owned yaks, and 54 yak‐owning households were selected randomly. The government livestock officials of nine yak‐rearing highland districts were also included in the study. A cross‐sectional study was conducted based on a questionnaire survey and focussed mainly on herdsmen's practices to manage gid. Two sets of questionnaires were used for yak herders and livestock officials. Each predesigned questionnaire was semi‐structured and consisted of both open– and closed‐ended questions.

Results

The study revealed gid as a major cause of yak mortality. Gid occurred more in winter during migration and most herders lost one to three yaks annually. Herdsmen kept an average of two watchdogs and dewormed them once annually. Similarly, calves were also dewormed once annually. The carcasses of dead yaks were fed to dogs. Livestock officials were optimistic about controlling the disease in the future, despite the yak areas being difficult to access. Most herders had not attended the gid awareness programme. The animal health worker visited herds once annually. In absence of animal health workers, most herdsmen resorted to different practices to treat affected yaks –the most common practice being surgery. Gid was mentioned to harm herdsmen's economy.

Conclusions

The study concluded that for effective management of gid in Laya, livestock agencies must create more awareness on gid, increase the frequency of visits by animal health workers to yak herds, and increase the frequency of deworming of watchdogs and calves.

New Insights Into the Peculiar World of the Shepherd-Dog Parasites: An Overview From Maremma (Tuscany, Italy)

Several developments have been recently achieved to understand pet-dog parasites and their relationship with hosts; however, parasites' presence and distribution in shepherd-dog have been mainly neglected; this knowledge gap is of critical sanitary importance, as shepherd-dogs could harbor zoonotic helminths including Echinococcus granulosus sensu lato. The related human disease, cystic echinococcosis, is a worldwide neglected disease, with high endemicity in the Mediterranean Basin. To evaluate the presence of E. granulosus and other parasites, a sheep-dog population from the province of Grosseto (Tuscany, Italy) has been investigated. Overall, 648 dog fecal samples obtained from 50 modern sheep farms, having a total of 216 dogs, were collected. Specimens were analyzed using a standardized centrifugal flotation method (specific gravity = 1.3). Taeniid eggs detected were further isolated using a sieving/flotation technique. DNA was isolated from eggs for PCR and sequence analyses for species identification (gene target: 12S rRNA and nad1). Thirty-nine (78%) farms tested positive for at least one parasite species or genus. The most represented intestinal helminths were Toxocara spp. in 64% of farms, followed by Ancylostomatidae (58%), Trichuris vulpis (50%), Capillaria spp. (34%), and taeniids (32%). Sequence analyses confirmed the presence of Taenia hydatigena in seven farms, Taenia (syn. Multiceps) multiceps in five farms, and T. pisiformis in one farm. No DNA was extracted from four previously taeniid egg-positive farms. No amplification of amplicon corresponding to E. granulosus was achieved in the investigated farms. Although not entirely expected, Spearman's test showed a positive correlation between flock size and the number of dogs per farm (ρ = 0.588, P < 0.001). The quantitative analysis reported that the home slaughter practice was affected neither by the flock size nor by the number of dogs per farm. The probability to diagnose farms positive for taeniids had been increased by about 35% for each dog unit increase [odds ratio (OR) = 1.35, P = 0.012]. In conclusion, the wide distribution of T. hydatigena and T. multiceps detected in the present study clearly reveals that dogs have still access to raw offal, a major risk for the transmission of E. granulosus. Home slaughtering is an unavoidable practice, and more efforts must be undertaken by the public health system to prevent and control potential zoonotic taeniids.

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.

Coenurosis of Yak, Bos grunniens, caused by Taenia multiceps: A Case Report with Molecular Identification in Qinghai Tibetan Plateau Area, China

Coenurosis is an important zoonotic helminthic disease caused by the larval stage of the tapeworm Taenia multiceps. This parasite typically infects the brain of the intermediate hosts, including sheep, goat, cattle and even humans. We report a case of T. multiceps infection in a yak confirmed by clinical symptoms, morphological characteristics, and molecular and phylogenetic analyses. The coenurus was thin-walled, whitish, and spherical in shape with a diameter of 10 cm. The parasite species was identified as T. multiceps by PCR amplification and sequencing of the 18S rRNA, cox1 and nad1 genes. Three gene sequences all showed high homology (all above 97%) with the reference sequences from different hosts. Moreover, phylogenetic reconstructions with the 3 published Taenia gene sequences confirmed that the Qinghai yak isolate was closely related to T. multiceps. Although there are advanced diagnosis and treatment methods for coenurosis, early infection is difficult to diagnose. Importantly, the findings of yak infection case should not be ignored due to its zoonotic potential.

Comparative molecular characterization and phylogenetic analysis of cerebral and non-cerebral coenurosis in Indian goats

Coenurus cerebralis is the larval stage of Taenia multiceps, which infects the muscles and brain of goats and, to a lesser extent, sheep. The resulting cerebral and non-cerebral infections caused by the larval form (metacestode) of this cestode are commonly known as coenurosis. A weak emaciated carcass of five months old female goat, on necropsy, revealed numerous parasitic cysts (n = 56, grossly visible) in the visceral cavity including heart, diaphragm, thoracic cavity, abdominal cavity and pelvic inlet. A large number of variable sized parasitic cysts were also observed embedded in the pericardium and myocardium causing functional damage to the heart. The parasite caused extensive tissue damage at gross and microscopic levels in the heart including traumatic destruction of the myocardium with degenerative and necrotic changes and infiltration of mononuclear cells. On parasitological examination, the cysts were identified as Coenurus cerebralis, as the scolices had characteristic four suckers and a rostellum with a double crown of hooks. Further confirmation was done using polymerase chain reaction targeting specific ND1 and CO1 genes. Phylogenetic analysis of CO1 and ND1 genes showed a major branch comprising two clades of T. multiceps grouped as separate entities with the first clade showing T. multiceps/Coenurus cerebralis native CIRG strain (cerebral) being placed in proximity to T. multiceps/Coenurus cerebralis CIRG strain (non-cerebral/visceral) compared to the Chinese strains of T. multiceps. The phylogenetic analysis of ND1 and CO1 genes of C. cerebralis of cerebral and non-cerebral isolates revealed close proximity but expressed in two different disease forms (i.e., visceral coenurosis and neural coenurosis) which indicated that they were very close divergent from a common ancestor. On the basis of the observations it was concluded that goat died due to cardiac dysfunction resulting from severe systemic infection of metacestode of T. multiceps was closely related to isolate that caused neural coenurosis in another goat. Based on the sequencing analysis and phylogenetic information, the possible differences in the clinical manifestation (neural or visceral) could be attributed to the pathogenesis.

Molecular characterization and phylogenetic analysis of Taenia multiceps from China

Taenia multiceps, one of the most widely distributed zoonotic tapeworm parasites, is able to parasitize the small intestine of canids. The metacestode of T.multiceps is fatal to ruminants and causes important economic losses in livestock. However, molecular characteristics of T.multiceps and coenurus in China are still unclear. In this study, 36 goat isolates of the coenurus stage and 18 dog isolates of the adult stage of T.multiceps were obtained from three geographical areas in China and the isolated parasite above were analyzed by amplifying the partial of cytochrome coxidase subunit 1(pcox1), 12S ribosomal RNA (12S rRNA) from mitochondrial DNA (mtDNA) regions and an internal transcribed spacer (ITS) of ribosomal DNA (rDNA). These DNA sequences obtained from T.multiceps and coenurus were employed to evaluate the nucleotide diversity and confirm the relationship between T.multiceps and coenurus. Sequences variation were 0-1.4%, 0-1.5%, 0-4.2% for pcox1, 12S rRNA and ITS, respectively, among T.multiceps and coenurus isolates obtained in this study. In Sichuan province, sequence variations for Coenurus cerebralis isolated from Yaan city were 0-1.4% for pcox1, 0-1.0% for 12S rRNA and 0-2.1% for ITS. In Hunan province, variations were 0-1.0%, 0-1.5% and 0-3.3% for corresponding genes for non-coenurus cerebralis isolated from Changsha city, while variations of T.multiceps isolates from Xiangxi autonomous prefecture were 0-1.0%, 0-1.1% and 0-3.4% for pcox1, 12S rRNA and ITS, respectively. Phylogenetic analysis based on pcox1 sequences indicated that all cerebral and noncerebral metacestodes belong to T.multiceps. These results provide reference values for future molecular epidemiological and biological study on T.multiceps in dogs and intermediate hosts.

Genetic characterization of three mitochondrial gene sequences of goat/sheep-derived coenurus cerebralis and cysticercus tenuicollis isolates in Inner Mongolia, China

Taenia multiceps and Taenia hydatigena are widely distributed tapeworms of canids. Due to a lack of genetic information on these two parasites in China, in this study we analyzed six coenurus cerebralis and two cysticercus tenuicollis cysts from goats or sheep in Inner Mongolia, northern China by amplifying three mitochondrial genes (cox1, nad4, and cytb). Two haplotypes were obtained at each locus for either of the two Taenia cestode species, with ten nucleotide sequences being novel. The degrees of genetic variations were 1.18%, 0.61% and 0.52% for coenurus cerebralis, and 0.24%, 0.46% and 0.35% for cysticercus tenuicollis at the cox1, nad4 and cytb loci, respectively. This is the first molecular description of animal-derived metacestodes of T. multiceps and T. hydatigena in Inner Mongolia, China. Novel nucleotide sequences might reflect endemic genetic characterization of the two cestodes. The present data are useful to explore the biological and epidemiological significance of intra-specific variations within both Taenia cestodes.

Clinical, pathological and molecular evaluations and CT scan screening of coenurosis (Coenurus cerebralis) in sheep and calves

Abstract The aims of this study were to diagnose coenurosis by means of computerized tomography (CT) scan imaging and molecular characterization of the CO1 gene using the polymerase chain reaction (PCR). Sheep and calves were necropsied, and CT scans on the cephalic region were performed on the animals. Sections of brain tissue infected with parasites were then stained with hematoxylin and eosin for microscopic examination. Material collected from brain cysts was fixed in 70% ethanol. PCR amplification was carried out using the CO1 mitochondrial gene. A total of 60 calves and 80 sheep were examined clinically and, of these, 15 calves and 38 sheep showed signs of depression, with counterclockwise circling movements and altered head carriage. Four sheep and one calf were necropsied, and C. cerebralis cysts were detected in all of them. A hypodense cyst was monitored in the right cerebellar hemisphere on a CT scan on one sheep. A cyst was found in the left frontal lobe on a CT scan on one calf. Microscopically, C. cerebralis cysts were surrounded by a fibrous or epithelial wall that presented necrosis on cerebral sections of both the sheep and the cattle. The CO1-PCR assay yielded a 446 bp band, which was sequenced and phylogenetically analyzed: the results confirmed the presence of T. multiceps. This study reports the first use of CT imaging on naturally infected calves and sheep for diagnosing coenurosis.

Genetic characterisation of Taenia multiceps cysts from ruminants in Greece

This study was designed to genetically characterise the larval stage (coenurus) of Taenia multiceps from ruminants in Greece, utilising DNA regions within the cytochrome c oxidase subunit 1 (partial cox1) and NADH dehydrogenase 1 (pnad1) mitochondrial (mt) genes, respectively. A molecular-phylogenetic approach was used to analyse the pcox1 and pnad1 amplicons derived from genomic DNA samples from individual cysts (n=105) from cattle (n=3), goats (n=5) and sheep (n=97). Results revealed five and six distinct electrophoretic profiles for pcox1 and pnad1, respectively, using single-strand conformation polymorphism. Direct sequencing of selected amplicons representing each of these profiles defined five haplotypes each for pcox1 and pnad1, among all 105 isolates. Phylogenetic analysis of individual sequence data for each locus, including a range of well-defined reference sequences, inferred that all isolates of T. multiceps cysts from ruminants in Greece clustered with previously published sequences from different continents. The present study provides a foundation for future large-scale studies on the epidemiology of T. multiceps in ruminants as well as dogs in Greece.

Is the red fox (Vulpes vulpes) a competent definitive host for Taenia multiceps?

Background

Shepherd and stray dogs are thought to represent the primary definitive hosts of Coenurosis by Taenia multiceps, due to their feeding habits which translate into high chances of coming into contact with infected intermediate hosts. Nonetheless, little attention has been paid to the role of the red fox (Vulpes vulpes) in the epidemiology of coenurosis. In fact a knowledge gap exists on the role played by red foxes in the epidemiology of Taenia multiceps and the capability of this parasite to produce fertile and viable eggs in this wild canid, i.e. on the occurrence of a sylvatic cycle.

This study investigates the role of the red fox (Vulpes vulpes) in the epidemiology of T. multiceps and related metacestodoses.

Methods

The small intestine of 63 red foxes was macroscopically examined for the presence of cestodes. Adult parasites were identified morphologically as being T. multiceps. Tapeworm eggs were counted and stored at 4 °C in physiological saline solution prior to experimental infection of four sheep and one goat. Sheep were inoculated orally on Day 0 with 3000 (sheep 1), 5000 (sheep 2 and 3) or 7000 eggs (sheep 4), while the goat was infected with 5000 eggs of T. multiceps. The animals were followed-up regularly by MRI and underwent surgical treatment between days 180 to day 240 post infection. Collected coenuri were identified using morphological and molecular methods.

Results

A total of 6.3 % of red foxes were found infected with T. multiceps and the eggs obtained from the worms were determined to have a viability of 45.4 %. Two of the challenged sheep and the goat developed disease compatible with T. multiceps. Morphometrical features of the cysts were consistent with those of T. multiceps; nucleotide amplification and sequencing of mitochondrial genes (i.e., cox1 and Nd1) from the metacestode material confirmed the identification.

Conclusions

The present study is the first to provide evidence of the role of the red fox as a competent definitive host for T. multiceps, thus changing the epidemiological scenarios of infections by this cestode.

Experimental cerebral and non-cerebral coenurosis in goats: A comparative study on the morphological and molecular characteristics of the parasite

This experimental study was conducted to test whether cerebral and non-cerebral forms of Coenurus cerebralis belong to one origin or they are originated from two different tape worms. In the first step of the study, two groups of dogs were orally infected with the protoscoleces of cerebral and non-cerebral cysts and four months after infection, the adult worms were collected and morphologically characterized. Then the obtained eggs from two groups of adult worms were orally inoculated to two groups of goats to trace the predilection sites and also to compare the morphological and molecular characteristics of the larval stage of the parasites. The results showed that, both cerebral and non-cerebral coenuri, produced morphologically similar worms in the experimentally infected dogs. We observed only non-cerebral coenurus cysts in two groups of experimentally infected goats and the morphological characteristics of the cysts of two different groups were also similar. The molecular findings also showed that the cysts of two groups were 100% identical to each other based on the CO1 and nad1 sequences. In conclusion, our morphological and molecular findings reinforce the evidence that Taenia multiceps is the single origin of both cerebral and non-cerebral form of C. cerebralis but in goats, the cysts show more tendency to non-cerebral organs.