Acute coenurosis of dairy sheep from 11 flocks in Greece

Acute coenurosis in lambs

Six 100-day-old mixed-breed lambs were examined in a farm with a semi-intensive system due to neurologic signs. Cachexia, bilateral blindness, stupor, severe drowsiness and lethargy with left and right movements of the head and neck were recorded after awakening and stimulation. Lambs died 10 days after the onset of the clinical signs. The lambs were necropsied, and after routine parasitology, bacteriology and histopathology, the occurrence of acute coenurosis was confirmed due to finding multiple cystic structures in the brain tissue. All lambs of the herd were treated with albendazole (orally, 25 mg/kg, two doses with an interval of 14 days). All shepherd dogs were treated with popantel (orally, one tablet/10 kg, two doses with an interval of 14 days). The affected lambs died despite this treatment. No new case of the disease was observed after the initiation of control measures. The present study shows the importance of preventive measure against coenurosis in a semi-intensive sheep farming system that includes implementing consistent parasite control programme in dogs being in contact with sheep.

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.

Molecular characterization and phylogenetic studies of Echinococcus granulosus and Taenia multiceps coenurus cysts in slaughtered sheep in Saudi Arabia

Taeniids, consisting of two genera Echinococcus and Taenia, are obligatory tapeworms of mammals, and their pathogenicity was due to infection with larval stages. Hydatid (the larval stage of Echinococcus granulosus) and coenurus (the larval stage of Taenia multiceps) cysts are prevalent in domestic, wild ruminants, livestock, swine, and dogs, and accidentally they could also be found in humans. They lead to different clinical manifestations that cause economic loss in livestock and human morbidity. In Saudi Arabia, few studies were performed on hydatid and coenurus cyst genetic variations. The main goal of the present study was to identify E. granulosus and T. multiceps cyst isolates collected from slaughtered Harri sheep in Saudi Arabia by partial sequencing with PCR amplification of the cytochrome C oxidase 1 (COX1) gene. Molecular and phylogenetic evaluation based on COX1 sequences indicated that cyst isolates belong to E. granulosus and T. multiceps, respectively, successfully submitted in NCBI Genbank. Molecular characterization showed a low nucleotide diversity with two submitted isolates of coenurus with related isolates of Genbank. Conversely, E. granulosus isolates showed higher nucleotide diversity. The reported data could serve as a foundation for future molecular epidemiological and biological studies.

First Report on Molecular Characterization of Taenia multiceps Isolates From Sheep and Goats in Faisalabad, Pakistan

Coenurus cerebralis is the larval stage of Taenia multiceps commonly found in the brain (cerebral form), intramuscular and subcutaneous tissues (non-cerebral form) of ungulates. Globally, few reports exist on the molecular characterization and genetic diversity of C. cerebralis with none available for Pakistan. The current study molecularly characterized 12 C. cerebralis isolates surgically recovered from sheep (n = 4) and goats (n = 8) from a total of 3,040 small ruminants using a portion of the cytochrome c oxidase subunit 1 (cox1) mitochondrial (mt) gene. NCBI BLAST search confirmed the identity of each isolate. A high haplotype and a low nucleotide diversity with three haplotypes from the 12 isolates were observed. The findings suggest the existence of unique haplotypes of C. cerebralis in Pakistan. The negative value of Tajima's D and the positive value of Fu's Fs were inconsistent with population expansion, however, the sample size was small. Bayesian phylogeny revealed that all Pakistani isolates alongside the Chinese sequences (obtained from GenBank) constituted a cluster while sequences from other regions constituted another cluster. This is the first molecular study to determine the genetic diversity of C. cerebralis in Pakistan and serves as a foundation for prospective studies on the prevalence and population structure of C. cerebralis in the country. Furthermore, in this study, we amplified only a partial segment of the cox1 gene from a limited sample size. This could have implications on the interpretation of the actual population structure in reality. Thus, we recommend future studies to consider a larger sample size in a massive epidemiological survey for further insights.

Characterization of the parasite-induced lesions in the posterior segment of the eye

Ocular lesions are frequently associated with different parasitic infections. The classes of infection include protozoa, nematodes, cestodes, and ectoparasites. Ocular parasitic infections can manifest in any part of the eye; the disease manifestations are frequently characterized as either posterior or anterior eye disease. Parasite-induced lesions may be due to damage directly caused by the parasite, indirect pathology caused by toxic products or the immune response initiated by infectious parasitism. This review characterized the parasite-induced lesions in the posterior segment of the eye. Prompt diagnosis and early treatment of these lesions can reduce ocular morbidity. The method of the literature search was conducted on PubMed, Elsevier Scopus database, and Google Scholar with no limitation on the year of publication databases. It was limited to English articles published for ocular lesions in clinical studies and was focused on parasitic infections of the eye.

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.

Clinical and morphopathological characteristics of an enzootic occurrence of acute coenurosis (Coenurus cerebralis) in a sheep herd

In this study, 30 sheep from a flock suddenly showed acute neurological symptoms associated with more than 30 % mortality. At necropsy, thickening associated with congestion and turbidity of meningeal membranes particularly on cerebellum, focal to multifocal necrotic areas and whitish spots measuring 1 to 3 cm in diameter were observed in the cortex of cerebrum and cerebellum. Grossly, numerous white tracts were also observed in the myocardium. Histopathologically, the cross sections of coenurus larvae associated with necrotic suppurative meningoencephalitis were observed. Multiple necrotic areas were also observed in the gray matter of cerebellum due to migration of the larvae with an extensive infiltration of eosinophils and neutrophils. In the heart, multifocal granulomatous myocarditis was diagnosed. No growth was seen in bacterial cultures of the brain and heart. Also, no bacteria were seen in these tissues stained with Ziehl-Neelsen and Brown-Brenn Gram stain. On basis of gross and histopathologic lesions, acute coenurosis was diagnosed. Unlike chronic coenurosis, acute form of the disease rarely reported in sheep.