Intranuclear coccidiosis of testudines ? the life cycle discovered

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62157124%3A16170%2F17%3A43875541" target="_blank" >RIV/62157124:16170/17:43875541 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Intranuclear coccidiosis of testudines ? the life cycle discovered

Original language description

Intranuclear coccidiosis of testudines? (known as TINC) is an emerging disease in chelonians. An intranuclear coccidian parasite causing lethal systemic disease in chelonians was first identified in tissues of the radiated tortoises (Astrochelys [Geochelone] radiata) histologically and by electron microscopy in 1990. Subsequently, the systemic intranuclear coccidiosis was confirmed in numerous tortoises, when the similar nonspecific symptoms (anorexia, lethargy, weakness, weight loss) were described. In 2006, the diagnostics by histological techniques and electron microscopy was supplemented by DNA-based diagnostics. Partial sequences of the 18S rDNA can be targeted by PCR assay for post- and antemortem diagnosis. Attempts to describe the TINC oocysts in faeces of tortoises have failed, however unsporulated oocysts were seen in tissues. Until our study, the identification of exogenous stages, life cycle and way of transmission of the intranuclear coccidium responsible for the TINC have not been discovered. We report herein the discovery of oocysts of an eimeriid coccidium in faeces of naturally infected leopard tortoises (Stigmochelys [Geochelone] pardalis) and their causal associations with TINC, which was proved by the partial 18S rDNA sequence analysis and experimental transmissions. Juvenile tortoises of S. pardalis were infected perorally with sporulated oocysts from the naturally infected individual. The tortoises started to shed unsporulated oocysts one month post infection. Symptoms of the infection developed few weeks later. Postmortally, the tissues were examined using histopathology, transmission electron microscopy and PCR. Histological findings showed numerous intracellular stages mainly in intestine, liver, lungs and kidney. Blood and all 16 tested organs were PCR positive. The obtained partial 18S rDNA sequences were homologous with GenBank sequences from previous TINC cases.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

40301 - Veterinary science

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů