Coenurosis in a beef cattle herd in Greece

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.

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.

First report of an outbreak of cerebral coenurosis in Dhofari goats in Oman

This study documented the first outbreak of cerebral coenurosis in goats in Salalah, southern Oman. Deaths of 130 (16.6%) adult native goats in a herd (n=780) were reported from January to June 2017. Affected goats showed various nervous signs ended by death. Investigations for thiamine deficiency, polioencephalomalacia, caprine arthritis encephalitis, and listeriosis were negative. Upon necropsy, multiple (1-4) thin-walled cysts 2-3.5 cm in diameter containing clear fluid with numerous clusters of protoscolices in the cerebrum and cerebellum had replaced the brain parenchyma, causing space-occupying lesions. Parasitologically, the recovered cysts were Coenurus cerebralis, based on the arrangement of protoscolices, and the number and size of their hooks. Morphologically, each protoscolex had four suckers and a rostellum with double-crown hooks. The large and small hooks were 157.7±0.5 µm and 115±0.6 µm in length, respectively. Histopathologically, the parasite destroyed the affected tissues associated with multifocal to diffuse lymphocytic, non-suppurative meningoencephalitis; ischemic neuronal necrosis; and malacia. This is the first report of cerebral coenurosis in livestock in Oman, which should alert the local public health authorities for the application of prevention and control measures.

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.

Morphological and molecular characterization of bovine coenurosis in Sardinia, Italy

Coenurosis is a central nervous system disease of wild and domestic ruminants caused by Coenurus cerebralis, a bladder worm stage of Taenia multiceps). Even in Sardinia island, this metacestode seems to be widespread in sheep (Scala et al. Vet Parasitol 143(3-4):294-298, 2007) where coenurosis is an important health problem (Varcasia et al. Parasitol Res 99(5):622-626, 2006) the last and unique report of coenurosis in cattle was in 1990 (Cubeddu et al. 1990). In the present paper, a case of bovine coenurosis in Sardinia was described 22 years after the first report with a morphological a biomolecular characterization. A 2-year-old Limousine bull was euthanized in the Bolotana (NU) municipality (Central Sardinia). The remote anamnesis achieved from the farmer reporting that the bull showed neurological symptoms from 1 year of age previously classified as nutritional problems by the farm's veterinary. The breeder also says that the bull have by self-produced the skull fracture by hitting a gaff in the farm. The skull was opened and the brain removed and carefully examined showing two coenurus cysts containing clear fluid with numerous scoleces both in the right hemisphere. Morphological features of the cysts and mt-DNA sequencing confirm that the parasites were T. multiceps Coenuri.