Although the validity of the coccidian species, Eimeria mivati, has been questioned by many researchers for a long time there has not been any molecular analysis that would help resolve this issue. Here we report on the discovery of the two types of small ribosomal subunit (18S) gene within the Eimeria mitis genome that correspond to the known 18S sequences of E. mitis and E. mivati, and this is in conflict with the existence of E. mivati as an independent species. We have carried out five single oocyst isolations to obtain five single-oocyst-derived strains of E. mitis and these were analyzed by the sequencing of 18S and mitochondrial cytochrome c oxidase subunit I genes. The two types of 18S gene were found to be present in each strain in roughly equal ratios. This indicates that if the strains carrying only one or the other 18S type exist, they will likely cross-breed and still represent a single species. However, the more probable explanation is that all strains of E. mitis contain two types of 18S gene and that the occasional detection of only one or the other type by sequencing might be caused by insufficient sampling. This is also the first report of the two types of 18S gene in Eimeria, which has already been described in some other apicomplexan species, most notably Plasmodium. We also found that these two types of ribosomal RNA differ significantly in their secondary structure. The biological significance of the two 18S gene variants in E. mitis is not known, however, we hypothesize that these variants might be used in different stages of the parasite's life-cycle as it is in other apicomplexan species investigated so far.
- MeSH
- atenuované vakcíny MeSH
- Eimeria klasifikace genetika imunologie izolace a purifikace MeSH
- feces parazitologie MeSH
- fylogeneze MeSH
- kokcidióza parazitologie veterinární MeSH
- kur domácí parazitologie MeSH
- malé podjednotky ribozomu eukaryotické genetika MeSH
- molekulární sekvence - údaje MeSH
- molekulární typizace veterinární MeSH
- nemoci drůbeže parazitologie MeSH
- oocysty MeSH
- protozoální DNA chemie genetika MeSH
- protozoální vakcíny MeSH
- respirační komplex IV genetika MeSH
- RNA protozoální chemie genetika MeSH
- RNA ribozomální 18S chemie genetika MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Seven- to eight-week-old rabbits were infected with Eimeria intestinalis Cheissin, 1948, a highly immunogenic coccidium, or Eimeria flavescens Marotel et Guilhon, 1941, which is weakly immunogenic. Immune response was investigated at 7, 14 and 21 days post inoculation (DPI). The level of serum immunoglobulins, lymphocyte proliferation stimulated by parasite antigens and weight of mesenteric lymph nodes (MLN) showed similar dynamics in rabbits inoculated with both coccidia species. The amount of serum IgG and IgM, but not IgA, was increased from 14 DPI. The lymphocytes from MLN of infected animals significantly reacted to stimulation with parasite antigen 14 and 21 DPI and MLN were enlarged at 14 DPI. Thus, both parasite species elicited immune response characterized by these parameters in a similar manner despite of their different immunogenicity. The only apparent difference in the responses was in the percentage of CD8+ lymphocytes in the specific site of parasite development (the last third of the small intestine in E. intestinalis, caecum in E. flavescens), which increased in rabbits infected with E. intestinalis but not with E. flavescens. This parameter reflects the status of local immunity and hence the results suggest that the local reaction plays an important role in induction of protective immunity to coccidia in rabbits.
- MeSH
- aktivace lymfocytů MeSH
- CD4-pozitivní T-lymfocyty cytologie imunologie MeSH
- CD8-pozitivní T-lymfocyty cytologie imunologie MeSH
- Eimeria imunologie patogenita MeSH
- ELISA MeSH
- financování organizované MeSH
- kokcidióza imunologie MeSH
- králíci MeSH
- mezenterium imunologie MeSH
- protilátky protozoální krev MeSH
- protozoální infekce imunologie MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
Naive and immune specific-pathogen-free rabbits were inoculated in the duodenum with sporocysts of Eimeria coecicola or Eimeria intestinalis. Samples were taken from the following tissues: duodenum (site of penetration of sporozoites), ileum (specific target site of the endogenous development of E. intestinalis), vermiform appendix (target site of E. coecicola) and two extraintestinal sites, mesenteric lymph nodes (MLNs), and spleen. The presence of sporozoites was checked by immunohistochemistry. In rabbits primary-infected with E. coecicola, large numbers of sporozoites were detected in the duodenum, extraintestinal sites, and vermiform appendix. The abundance of sporozoites in the spleen, MLN, and appendix was significantly reduced in the immune rabbits, and the migration seemed impeded. In the rabbits infected with E. intestinalis, sporozoites were absent in the spleen and MLN, indicating that the route of migration is different from that of E. coecicola. The number of sporozoites in the crypts of the ileum was markedly reduced in the immune animals.
- MeSH
- Eimeria imunologie patogenita růst a vývoj MeSH
- financování organizované MeSH
- interakce hostitele a parazita MeSH
- kokcidióza imunologie parazitologie MeSH
- králíci MeSH
- lymfatické uzliny parazitologie MeSH
- organismy bez specifických patogenů MeSH
- parazitární nemoci střev MeSH
- Peyerovy pláty metabolismus parazitologie MeSH
- protilátky protozoální imunologie metabolismus MeSH
- slezina parazitologie MeSH
- sporozoiti imunologie patologie růst a vývoj MeSH
- tenké střevo metabolismus parazitologie patologie MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- MeSH
- buněčná imunita MeSH
- Eimeria imunologie MeSH
- kokcidióza imunologie MeSH
- ptáci imunologie parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
