Non-biting midges Dotaz Zobrazit nápovědu
Sand flies remain the only proven vectors of Leishmania spp. but recent implementation of PCR techniques has led to increasing speculation about "alternative vectors", including biting midges. Here, we summarize that PCR has considerable limits for studing the role of bloodsucking arthropods in the epidemiology of leishmaniasis. The Leishmania life cycle in the sand fly includes a complex series of interactions which are in many cases species-specific, the early phase of the infection is, however, non-specific to sand flies. These facts should be considered in detection of Leishmania in ,"alternative" or "new" vectors to avoid mistaken speculation about their vector competence.
Equine insect bite hypersensitivity (IBH) is a seasonal IgE-mediated dermatosis caused by bites of insects of the genus Culicoides. A familial predisposition for the disease has been shown but, except for the MHC, the genes involved have not been identified so far. An immunogenomic analysis of IBH was performed in a model population of Old Kladruby horses, all living in the same environment. Clinical signs of IBH were used as phenotypic manifestation of IBH. Furthermore, total serum IgE levels were determined in the sera of these horses and used as an independent phenotypic marker for the immunogenetic analysis. Single nucleotide polymorphisms (SNPs) in candidate immunity-related genes were used for association analyses. Genotypes composed of two to five genes encoding interferon gamma -IFNG, transforming growth factor beta 1 -TGFB1, Janus kinase 2 -JAK2, thymic stromal lymphopoietin -TSLP, and involucrin -IVL were associated with IBH, indicating a role of the genes in the pathogenesis of IBH. These findings were supported by analysis of gene expression in skin biopsies of 15 affected and 15 unaffected horses. Two markers associated with IBH, IFNG and TGFB1, showed differences in mRNA expression in skin biopsies from IBH-affected and non-affected horses (p<0.05). Expression of the gene coding for the CD14 receptor molecule -CD14 was different in skin biopsies at p<0.06. When total IgE levels were treated as binary traits, genotypes of IGHE, ELA-DRA, and IL10/b were associated with this trait. When treated as a continuous trait, total IgE levels were associated with genes IGHE, FCER1A, IL4, IL4R, IL10, IL1RA, and JAK2. This first report on non-MHC genes associated with IBH in horses is thus supported by differences in expression of genes known to play a role in allergy and immunity.
- MeSH
- alergeny imunologie MeSH
- atopická dermatitida genetika imunologie veterinární MeSH
- Ceratopogonidae imunologie MeSH
- cytokiny genetika MeSH
- exprese genu MeSH
- hlavní histokompatibilní komplex MeSH
- imunoglobulin E krev MeSH
- interferon gama genetika MeSH
- Janus kinasa 2 genetika MeSH
- jednonukleotidový polymorfismus MeSH
- koně MeSH
- kousnutí a bodnutí hmyzem genetika imunologie veterinární MeSH
- messenger RNA genetika MeSH
- nemoci koní genetika imunologie MeSH
- proteinové prekurzory genetika MeSH
- slinné proteiny a peptidy imunologie MeSH
- transformující růstový faktor beta1 genetika MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Strain CS-1T, a novel facultative anaerobic bacterium, was isolated from the larval gastrointestinal tract of the biting midge, Culicoides sonorensis, a vector of the epizootic haemorrhagic disease virus and the bluetongue virus. Cells were Gram-stain-positive, non-motile, non-spore-forming, pleomorphic rods. Optimal growth occurred at pH 7.5 and 37 °C. The G+C content of the genomic DNA was 38.3 mol%, estimated by using HPLC. The dominant cellular fatty acids were C14 : 0 (45.9 %) and C16 : 0 (26.6 %). The polar lipid profile comprised glycolipids, diphosphatidylglycerol, phospholipids and phosphoglycolipids. Respiratory quinones were not detected. Strain CS-1T had very low 16S rRNA gene similarity to members of the phylum Firmicutes: Macrococcus canis KM45013T (85 % similarity) and Turicibacter sanguinis MOL361T (88 % similarity). Phylogenetic analysis based on 16S rRNA, rpoB, gyrB genes, and conserved protein sequences of the whole genome revealed that strain CS-1T was related to members of the classes Bacilli and Erysipelotrichia within the phylum Firmicutes. Furthermore, average nucleotide identity and digital DNA-DNA hybridization analyses of the whole genome revealed very low sequence similarity to species of Bacilli and Erysipelotrichaceae (Macrococcus canis KM45013T and Turicibacter sp. H121). These results indicate that strain CS-1T belongs to the phylum Firmicutes and represents a new species of a novel genus, family, order and class. Based on the phenotypic, chemotaxonomic, phylogenetic and genomic characteristics, we propose the novel taxon Culicoidibacter larvae gen. nov., sp. nov. with the type strain CS-1T (=CCUG 71726T=DSM 106607T) within the hereby new proposed novel family Culicoidibacteraceae fam. nov., new order Culicoidibacaterales ord. nov. and new class Culicoidibacteria classis nov. in the phylum Firmicutes.
- MeSH
- Ceratopogonidae mikrobiologie MeSH
- DNA bakterií genetika MeSH
- druhová specificita MeSH
- Firmicutes klasifikace genetika MeSH
- fylogeneze * MeSH
- gastrointestinální trakt mikrobiologie MeSH
- larva mikrobiologie MeSH
- mastné kyseliny chemie MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- techniky typizace bakterií MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Insect bite hypersensitivity (IBH) is an allergic dermatitis of horses caused by bites of insects. IBH is a multifactorial disease with contribution of genetic and environmental factors. Candidate gene association analysis of IBH was performed in a group of 89 Icelandic horses all born in Iceland and imported to Europe. Horses were classified in IBH-affected and non-affected based on clinical signs and history of recurrent dermatitis, and on the results of an in vitro sulfidoleukotriene (sLT)-release assay with Culicoides nubeculosus and Simulium vittatum extract. Different genetic markers were tested for association with IBH by the Fisher's exact test. The effect of the major histocompatibility complex (MHC) gene region was studied by genotyping five microsatellites spanning the MHC region (COR112, COR113, COR114, UM011 and UMN-JH34-2), and exon 2 polymorphisms of the class II Eqca-DRA gene. Associations with Eqca-DRA and COR113 were identified (p < 0.05). In addition, a panel of 20 single nucleotide polymorphisms (SNPs) in 17 candidate allergy-related genes was tested. During the initial screen, no marker from the panel was significantly (p < 0.05) associated with IBH. Five SNPs associated with IBH at p < 0.10 were therefore used for analysis of combined genotypes. Out of them, SNPs located in the genes coding for the CD14 receptor (CD14), interleukin 23 receptor (IL23R), thymic stromal lymphopoietin (TSLP) and transforming growth factor beta 3 (TGFB3) molecules were associated with IBH as parts of complex genotypes. These results are supported by similar associations and by expression data from different horse populations and from human studies.
- MeSH
- alergie genetika imunologie veterinární MeSH
- Ceratopogonidae imunologie patogenita MeSH
- dermatitida genetika veterinární MeSH
- hlavní histokompatibilní komplex genetika MeSH
- koně genetika imunologie MeSH
- kousnutí a bodnutí hmyzem genetika imunologie MeSH
- Simuliidae imunologie patogenita MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Island MeSH
Interleukin-3 is a growth and differentiation factor for various hematopoietic cells. IL-3 also enhances stimulus-dependent release of mediators and cytokine production by mature basophils. Function of IL-3 has not been studied in horses because of lack of horse-specific reagents. Our aim was to produce recombinant equine IL-3 and test its effect on sulfidoleukotriene and cytokine production by equine peripheral blood leukocytes (PBL). Equine IL-3 was cloned, expressed in E. coli and purified. PBL of 19 healthy and 20 insect bite hypersensitivity (IBH)-affected horses were stimulated with Culicoides nubeculosus extract with or without IL-3. Sulfidoleukotriene (sLT) production was measured in supernatants by ELISA and mRNA expression of IL-4, IL-13 and thymic stromal lymphopoietin (TSLP) assessed in cell lysate by quantitative real-time PCR. Recombinant equine IL-3 (req-IL-3) had a dose dependent effect on sLT production by stimulated equine PBL and significantly increased IL-4, IL-13 and TSLP expression compared to non-primed cells. IL-3 priming significantly increased Culicoides-induced sLT production in IBH-affected but not in non-affected horses and was particularly effective in young IBH-affected horses (≤ 3 years). A functionally active recombinant equine IL-3 has been produced which will be useful for future immunological studies in horses. It will also allow improving the sensitivity of cellular in vitro tests for allergy diagnosis in horses.
- MeSH
- alergie imunologie veterinární MeSH
- Ceratopogonidae MeSH
- cytokiny genetika metabolismus MeSH
- interleukin-3 farmakologie MeSH
- klonování DNA * MeSH
- koně metabolismus MeSH
- kousnutí a bodnutí hmyzem imunologie veterinární MeSH
- leukocyty účinky léků metabolismus MeSH
- leukotrieny genetika metabolismus MeSH
- regulace genové exprese účinky léků MeSH
- rekombinantní proteiny MeSH
- stárnutí MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
