Immune Cell Reaction Associated with Coenurus cerebralis Infection in Sheep with Particular Reference to ELISA as a Diagnostic Tool

Simple Summary

Infected sheep with Coenurus cerebralis (C. cerebralis) were subjected to histopathological, hematological, immunological and serological examination. In histopathological sections, cerebral tissue showed an areolar cyst wall with many protoscolices attached to the tissue with necrosis and inflammatory cells’ aggregation. The infected sheep exhibited a significant alteration in blood profile when contrasted with apparently healthy sheep. Evaluation of ELISA specificity using two antigens showed specificities of 46.2% and 38.5% for fluid and scolex Ag, respectively. Meanwhile, accuracy ranged from 76.7% and 73.3% for fluid and scolex Ag, respectively. Levels of TNF-α and IFN-γ were significantly elevated in infected sheep when contrasted with control ones.

Abstract

Sturdy is a disease caused by Coenurus cerebralis (C. cerebralis) that typically affects the brain and spinal cord of sheep. So, this study aimed to detect the pathological, hematological and immunological changes caused by C. cerebralis in sheep. On examination, a total of 17 sheep out of 30 sheep (56.7%) from various regions in Egypt were found infected with C. cerebralis from May to August 2019. Each cyst was extracted from the sheep brain; in addition, tissue specimens were taken from the brain tissues for histopathological examination. The hematological profile was analyzed. Enzyme-Linked Immunosorbent Assay’s (ELISA) specificity and sensitivity were evaluated using cystic fluid and protoscolices antigens (Ag). The cell-mediated immunity against the C. cerebralis cyst was also assessed via quantitative Real Time—Polymerase Chain Reaction (qRT-PCR) to show alterations in mRNA expression of the Tumor Necrosis Factor-alpha (TNF-α) and gamma Interferon (IFN-γ) cytokines qRT-PCR. In histopathological sections, cerebral tissue showed an areolar cyst wall with many protoscolices attached to the tissue. The affected part showed prominent necrosis together with inflammatory cells’ aggregation. Hyperplastic proliferation of the ependymal cells was a common finding. The infected sheep exhibited significantly lower total erythrocyte numbers (ER), hemoglobin levels (Hb), packed cell volume (PCV), platelet numbers (PN) and segmented cell numbers compared to apparently healthy sheep. Despite the sensitivity for the indirect ELISA being 100% for both of the Ags (fluid and scolex), the evaluation of ELISA specificity using the two antigen (Ag) preparations showed specificities of 46.2% and 38.5% for fluid and scolex Ag, respectively. Meanwhile accuracy ranged from 76.7% and 73.3% for the fluid and scolex Ags, respectively, that showed the priority was directed to the fluid to be used as an ideal sample type for ELISA. Levels of TNF-α and IFN-γ were significantly elevated in infected sheep compared to non-infected control ones. In conclusion, C. cerebralis is a serious disease infecting sheep in Egypt revealing economic losses. Although this investigation supports preliminary information about the prevalence, pathological and serological characterization of C. cerebralis, further sequencing and phylogenetic analysis is needed to understand better the T. multiceps epidemiology in ruminants and canines in Egypt.

Oxidative stress markers, immune-regulating cytokines, and the pathological evaluation of sheep co-infected with Oestrus ovis and Coenuruscerebralis

This study aimed to evaluate the immune response using the immune-regulating cytokines as (IL-1β; MHC-I and MHC-II) associated with co-infected sheep Oestrusovis and Coenurus cerebralisas well as oxidative stress markers (malondialdehyde "MDA" and nitric oxide "NO"). So; sheep samples from different regions in Egypt showed different neurological signs, were examined for detection of the cause of the nervous manifestations. Moreover, the O. ovis and C. cerebralis cysts were collected and identified using scanning electron microscopy. The brain tissues were evaluated for different immunological genes such as MHC-I, MHC-II, and Interleukin-1β activity using quantitative real-time PCR (qRT-PCR) techniques, where the infected sheep showed higher MHC-I gene expression (10-fold), higher MHC-II gene expression (peaked at 25-fold), and higher IL-1β gene expression (14-fold) than the control group. The MDA level was significantly increased. Also, stress marker (nitric oxide) levels were significantly higher in infectedsheep than in negative control one. During gross pathology, migrating larvae of O. ovis andC. cerebralis were noticed In such areas, hemorrhages and patches of clotted blood were noticed. cysts with prominent protoscolices were also observed and were attached to the caudal region near the cerebellum.

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.

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.