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.Keywords: Coenurus cerebralis, CT imaging, PCR, sheep, calf, Turkey. ResumoOs objetivos deste estudo foram diagnosticar cenurose por tomografia computadorizada (CT) por imagem de digitalização e caracterização molecular do gene CO1, usando a Reação em Cadeia da Polimerase (PCR). Ovelhas e bezerros foram necropsiados, e uma tomografia computadorizada da região cefálica foi realizada nos animais. Em seguida, cortes microscópicos de cérebro infectado com parasitas foram corados com hematoxilina e eosina e posterior avaliação ao microscópio de luz. Em seguida, o material recolhido de cada cisto cerebral foi fixado em etanol a 70%. A amplificação pela PCR foi realizada utilizando-se o gene mitocondrial CO1. Um total de 60 bezerros e 80 ovelhas foram clinicamente examinados e, desses, 15 bezerros e 38 ovelhas apresentaram sinais de depressão, com movimentos circulares em sentido anti-horário, e desvio da cabeça. Quatro carneiros e uma vitela foram necropsiados, e cistos de C. cerebralis foram detectados nos animais. Um cisto hipodenso foi monitorado no hemisfério cerebelar direito por imagem do CT de um carneiro. O cisto foi encontrado no lobo frontal esquerdo por imagem do CT de um bezerro. Microscopicamente, cistos de C. cerebralis foram envolvidos por uma parede fibrosa ou epitelial, apresentando necrose em ambos os cortes cerebrais de ovinos e de bovinos. O ensaio CO1-PCR produziu uma banda de 446 pb, sequenciado e submetido à filogenia, confirmou ser T. multiceps. Este estudo relata a primeira utilização de imagens de CT em bezerros e ovelhas naturalmente infectados para o diagnóstico de coenurosis.

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

“…Also, intermittent clockwise and anticlockwise circling was noticed in goats with at least one cyst in each cerebral hemisphere (Table 1). These results are nearly similar to the findings of cerebral coenurosis in sheep (EDWARDS & HERBERT, 1982;GAZIOGLU et al, 2017).…”

“…Cerebral coenurosis is endemic in Middle Eastern countries, with many reports originating from Iran (KHEIRANDISH et al, 2012;MOGHADDAR, 2007;TAVASSOLI et al, 2011), Egypt (ABBAS & ELBESKAWY, 2016;AMER et al, 2017), Turkey (AVCIOGLU et al, 2011GAZIOGLU et al, 2017;GICIK et al, 2007), Jordan (ABO-SHEHADA et al, 2002) and Iraq (KARIM, 1979).…”

Cerebral Coenurosis of a Long-Tailed Goral, Naemorhedus caudatus, in Korea

“…Coenurus cerebralis is a metacestode of T. multiceps that infects the small intestine of carnivores [ 10 , 11 ]. The important intermediate hosts for T. multiceps are small ruminants such as sheep and goats [ 12 ], where oncospheres that infiltrate the brain or spinal cord develop into mature coenurus cysts in the central nervous system [ 13 ].…”

“…CT was used in the diagnosis of coenurosis in humans and other animals. Several scholars have reported that the cyst appears to be a hypoattenuating structure with a mass effect in the CT images [ 10 ]. The MRI images of the brain parenchyma infected with Coenurus cerebralis appear hypointense in the T1W image and hyperintense in the T2W image [ 12 ].…”

“…CT and MRI are diagnostic methods that can accurately determine the exact location and size of the cyst. This information is essential for the surgical removal of the parasitic cysts [ 10 ]. In our case, hypointense cyst was detected in the left cerebral hemisphere on CT examination.…”