RESUMO
Eimeria parasites cause enteric disease in livestock and the closely related Cyclospora cayetanensis causes human disease. Oocysts of these coccidian parasites undergo maturation (sporulation) before becoming infectious. Here, we assessed transcription in maturing oocysts of Eimeria acervulina, a widespread chicken parasite, predicted gene functions, and determined which of these genes also occur in C. cayetanensis. RNA-Sequencing yielded ~2 billion paired-end reads, 92% of which mapped to the E. acervulina genome. The ~6,900 annotated genes underwent temporally-coordinated patterns of gene expression. Fifty-three genes each contributed >1,000 transcripts per million (TPM) throughout the study interval, including cation-transporting ATPases, an oocyst wall protein, a palmitoyltransferase, membrane proteins, and hypothetical proteins. These genes were enriched for 285 gene ontology (GO) terms and 13 genes were ascribed to 17 KEGG pathways, defining housekeeping processes and functions important throughout sporulation. Expression differed in mature and immature oocysts for 40% (2,928) of all genes; of these, nearly two-thirds (1,843) increased their expression over time. Eight genes expressed most in immature oocysts, encoding proteins promoting oocyst maturation and development, were assigned to 37 GO terms and 5 KEGG pathways. Fifty-six genes underwent significant upregulation in mature oocysts, each contributing at least 1,000 TPM. Of these, 40 were annotated by 215 GO assignments and 9 were associated with 18 KEGG pathways, encoding products involved in respiration, carbon fixation, energy utilization, invasion, motility, and stress and detoxification responses. Sporulation orchestrates coordinated changes in the expression of many genes, most especially those governing metabolic activity. Establishing the long-term fate of these transcripts in sporulated oocysts and in senescent and deceased oocysts will further elucidate the biology of coccidian development, and may provide tools to assay infectiousness of parasite cohorts. Moreover, because many of these genes have homologues in C. cayetanensis, they may prove useful as biomarkers for risk.
Assuntos
Coccídios/genética , Coccidiose/genética , Eimeria/genética , Regulação da Expressão Gênica/genética , Animais , Biomarcadores/metabolismo , Galinhas/genética , Galinhas/parasitologia , Coccídios/patogenicidade , Coccidiose/parasitologia , Cyclospora/genética , Cyclospora/parasitologia , Eimeria/patogenicidade , Humanos , Gado/parasitologia , Modelos BiológicosRESUMO
Cyclospora cayetanensis es un protozoo coccidio con diversa prevalencia a nivel mundial que causa cuadros con diarrea acuosa y voluminosa tanto en pacientes inmunocompetentes como inmunocomprometidos. En estos últimos, además de producir cuadros entéricos más severos, puede cursar con compromisos biliares. Su distribución es cosmopolita, jugando un rol importante en su transmisión, el suelo, el agua y los alimentos contaminados, especialmente las verduras ingeridas crudas. El hombre, único reservorio constatado hasta el presente, elimina con las heces ooquistes inmaduros, que evolucionan en el ambiente transformándose en ooquistes maduros infectivos. Como otros coccidios, presenta un ciclo evolutivo complejo con formas sexuada y asexuada de reproducción en un único hospedador. El diagnóstico se basa fundamentalmente en el hallazgo de ooquistes ácido alcohol resistentes variables en materia fecal. Se han desarrollado métodos moleculares para su detección tanto en muestras fecales como ambientales y de alimentos.
Cyclospora cayetanensis is a coccidian protozoon with several prevalence worldwide that causes watery and voluminous diarrhea conditions both in immunocompetent and immunocompromised patients. In the latter, apart from originating more severe enteric diseases, it can occur with billiary involvement. Its distribution is cosmopolitan, with soil, water and contaminated food, especially consumption of raw vegetables, playing an important role in its transmission. Man, the only reservoir recorded so far, eliminates immature oocytes in feces, which evolve in the environment becoming infective- mature oocytes. Like other coccidians, it presents a complex evolutionary cycle with sexed and unsexed forms of reproduction in a single host. Diagnosis is mainly based on findings of variable acid-alcohol resistant variables in feces. Molecular methods have been developed for its detection in fecal samples and in environmental and food samples as well.
Cyclospora cayetanensis é um protozoo coccídio com diversa prevalência em nível mundial que causa quadros com diarreia aquosa e volumosa tanto em pacientes imunocompetentes como imunocomprometidos. Nestes últimos, além de produzir quadros entéricos mais severos, pode cursar com compromissos biliares. Sua distribuição é cosmopolita, tendo um papel importante na sua transmissão o solo, a água e os alimentos contaminados, especialmente as verduras ingeridas cruas. O homem, único reservatório constatado até o presente, elimina com as fezes oocistos imaturos, que evoluem no ambiente transformando-se em oocistos maduros infectivos. Como outros coccídios apresenta um ciclo evolutivo complexo com formas sexuada e assexuada de reprodução num único hospedeiro. O diagnóstico se baseia fundamentalmente no achado de oocistos ácido-álcool resistentes variáveis em matéria fecal. Foram desenvolvidos métodos moleculares para sua detecção tanto em amostras fecais quanto ambientais e de alimentos.
