Sarcocystis-Associated Encephalitis in Chickens

Mutalib, Ahmed; Keirs, R. W.; Maslin, William R.; Topper, Michael J.; Jp, Dubey

doi:10.2307/1591891

Cited by 25 publications

(14 citation statements)

References 4 publications

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“…Neurological signs associated with sarcocystosis have previously been described in several avian species (Jacobsen et al 1984;Aguilar et al, 1991;Dubey et al, , 2001bHillyer et al, 1991;Mutalib et al, 1995;Teglas et al, 1998;Spalding et al, 2002;Olson et al, 2007;Villar et al, 2008). However, encephalitis due to Sarcoystis infection has not so far been reported in pigeons (Smith et al, 1990;Suedmeyer et al, 2001).…”

Section: Discussionmentioning

confidence: 87%

A novelSarcocystis-associated encephalitis and myositis in racing pigeons

et al. 2009

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Sarcosporidian cysts in the skeletal muscle of domestic pigeons (Columba livia f. domestica) have previously been attributed to infection with Sarcocystis falcatula, which is shed in the faeces of the opossum (Didelphis virginiana). Here, we describe fatal spontaneous encephalitis and myositis associated with Sarcocystis infections in three flocks of racing pigeons with 47 of 244 animals affected. The clinical course was characterized by depression, mild diarrhoea, torticollis, opisthotonus, paralysis and trembling. Histopathological examination of 13 pigeons revealed generalized severe granulomatous and necrotizing meningoencephalitis and myositis with sarcosporidian cysts. Light and transmission electron microscopy identified cysts in heart and skeletal muscle of 1 to 2 mm in length and 20 to 50 mm in width. These were subdivided into small chambers by fine septae and filled with lancet-shaped cystozoites (7.5)1.5 mm) and dividing metrocytes, which is characteristic for Sarcocystis. The cysts had smooth walls and were devoid of protrusions typical of S. falcatula. Polymerase chain reaction amplification and sequencing of the internal transcribed spacer region (ITS-1) and the complete 28S rRNA identified a novel Sarcocystis species with only 51% ITS-1 nucleotide sequence similarity with S. falcatula. A phylogenetic comparison of the 28S rRNA revealed close sequence homologies with Frenkelia microti, Frenkelia glareoli and Sarcocystis neurona. The clinical, histopathological, electron microscopic and genetic data are unlike any previously described protozoan infections in pigeons, suggesting a novel, severe disease due to an as yet undescribed Sarcocystis species.

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Section: Discussionmentioning

confidence: 87%

A novelSarcocystis-associated encephalitis and myositis in racing pigeons

et al. 2009

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“…Sarcocystis spp. in chickens cause severe myositis [13] and occasionally neurological disease [14]. Sarcocystis infection in chickens has been reported in Hungary [1], Bulgaria [2], Russia [15], Papua New Guinea [13], Australia [13], Germany [3], the Czech Republic [16], Azerbaijan [17], China [18], Iran [19] and Brazil [20].…”

Section: Discussionmentioning

confidence: 99%

Morphological and Molecular Characterization of Sarcocystis Wenzeli in Chickens (Gallus gallus) in China

Pan

Huang

et al. 2020

Preprint

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Background: There has been considerable confusion concerning the number and classification of Sarcocystis spp. found in chickens. To date, no nucleotide sequences of Sarcocystis spp. from chickens have been provided in GenBank. The present study aimed to investigate the morphological and molecular characteristics of Sarcocystis spp. in chickens in China.Methods: Tissues from 33 chickens were collected in 2019. Sarcocysts were observed using light (LM) and transmission electron microscopy (TEM). Individual sarcocysts from different chickens were selected for DNA extraction, and five loci, 18S rDNA, 28S rDNA, the ITS-1 region (ITS-1), the mitochondrial cox1 gene (cox1), and the apicoplastic rpoB gene (rpoB), were amplified from each sarcocyst, cloned, sequenced and analyzed.Results: Only S. wenzeli was found in 14 of 33 (42.4%) chickens. Under LM, the sarcocysts were microscopic and exhibited palisade-like villar protrusions measuring 1.5–2.8 μm. The bradyzoites were lancet-shaped, measuring 9.2–12.6 × 1.5–3.5 μm. Ultrastructurally, the sarcocyst wall contained numerous stubby hill-like villar protrusions that were up to 1.2 μm long and 1.0 μm wide. The protrusions included scattered microtubules, which extended from the tips of the protrusions into the ground substance. The intraspecific similarity of the five loci (18S rDNA, 28S rDNA, ITS-1, cox1, and rpoB) among the newly obtained sequences ranged from 99.8–100%, 99.7–100%, 99.0–99.9%, 100% and 98.9–100%, respectively. The five loci showed different levels of interspecific sequence similarity with closely related species of Sarcocystis (e.g., 99.8%, 99.0–99.2%, 89.3-89.7%, 98.5%, and 97.5%, respectively, with S. anasi). Phylogenetic analysis based on three of the loci (18S rDNA, cox1, and rpoB) revealed that S. wenzeli formed an independent clade with Sarcocystis spp. that employ geese or ducks as intermediate hosts and canines as the known or presumed definitive host.Conclusions: The sequences of 18S rDNA, 28S rDNA, ITS-1, cox1 and rpoB from S. wenzeli reported here constitute the first records of genetic markers of Sarcocystis from chickens made available in GenBank. Based on sequence analysis, ITS-1 and rpoB are more suitable for discriminating S. wenzeli from closely related species of Sarcocystis. Phylogenetic analysis revealed that S. wenzeli presents a close relationship with Sarcocystis spp. from geese or ducks.

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“…Encephalitis caused by Sarcocystis spp. in chickens (Mutalib et al, 1995), a cockatiel (Jacobson et al, 1984), a Northern gannet (Spalding et al, 2002), raptors (Olson et al, 2007;Wünschmann et al, 2009Wünschmann et al, , 2010 and psittacines (Villar et al, 2008) was characterized by evidence of schizonts and merozoites within the neuronal lesions. In budgerigars experimentally infected with S. falcatula, tissue destruction due to schizogony was the predominant cause for inflammatory lesions.…”

Section: Discussionmentioning

confidence: 99%

Parasite distribution and early-stage encephalitis inSarcocystis calchasiinfections in domestic pigeons (Columba liviaf.domestica)

et al. 2014

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Pigeon protozoal encephalitis is a biphasic, neurologic disease of domestic pigeons (Columba livia f. domestica) caused by the apicomplexan parasite Sarcocystis calchasi. Despite severe inflammatory lesions of the brain, associated parasitic stages have only rarely been identified and the cause of the lesions is still unclear. The aim of this study was therefore to characterize the tissue distribution of S. calchasi within pigeons between the two clinical phases and during the occurrence of neurological signs. For this purpose, a semi-quantitative real-time polymerase chain reaction (PCR) was developed. Forty-five domestic pigeons were infected orally (via a cannula into the crop) with 200 S. calchasi sporocysts and euthanized in groups of three pigeons at intervals of 2 to 10 days over a period of 61 days. Tissue samples including brain and skeletal muscle were examined by histology, immunohistochemistry, and PCR. Schizonts were detected in the liver of one pigeon at day 10 post infection. A mild encephalitis was detected at day 20 post infection, around 4 weeks before the onset of neurological signs. At the same time, immature sarcocysts were present in the skeletal muscle. In seven pigeons a few sarcocysts were identified in the brain, but not associated with any lesion. These results suggest that the encephalitis is induced at a very early stage of the S. calchasi lifecycle rather than in the chronic phase of pigeon protozoal encephalitis. Despite the increasing severity of lesions in the central nervous system, the amount of sarcocysts did not increase. This supports the hypothesis of a delayed-type hypersensitivity response as the cause of the encephalitis. The study also demonstrated that S. calchasi DNA is detectable in tissues negative by histological methods, indicating a higher sensitivity of the real-time PCR.

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Sarcocystis-Associated Encephalitis in Chickens

Cited by 25 publications

References 4 publications

A novelSarcocystis-associated encephalitis and myositis in racing pigeons

A novelSarcocystis-associated encephalitis and myositis in racing pigeons

Morphological and Molecular Characterization of Sarcocystis Wenzeli in Chickens (Gallus gallus) in China

Parasite distribution and early-stage encephalitis inSarcocystis calchasiinfections in domestic pigeons (Columba liviaf.domestica)

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