Search results for "Yersinia"

Ultraviolet B Irradiation Affects Resistance of Rainbow Trout (Oncorhynchus mykiss) Against Bacterium Yersinia ruckeri and Trematode Diplostomum spat…

2007

Ultraviolet B (UVB) radiation is known to have various effects on the immune system of fish, but the effect on the actual disease resistance has remained largely unknown. Here we studied the effect of UVB on the resistance of rainbow trout (Oncorhynchus mykiss) against a bacterium Yersinia ruckeri, the causative agent of enteric red mouth disease, and a trematode parasite Diplostomum spathaceum, which causes cataracts in fish. The fish were exposed to UVB irradiation seven times in 14 days, and inoculated intraperitoneally with Y. ruckeri on day 5 after the first irradiation. On day 2 postinfection (p.i.), the number of viable bacteria in the kidney was lower in UVB-exposed than in unexpose…

Yersinia enterocolitica biotyypin 1A ja Y. enterocolitican kaltaisten bakteerikantojen geneettisen monimuotoisuuden ja lämpökestoisten enterotoksiini…

2007

Gut microbiota changes in rainbow trout, Oncorhynchus mykiss (Walbaum), during organic acid feed supplementation and Yersinia ruckeri infection

2013

Gut microbiota (GM) composition of vertebrates are considered to influence health parameters including immunological parameters in the host but knowledge of these issues in fish are sparse. We have performed a 45 day experimental study elucidating effects of dietary supplementation of organic acids (Mera Cid) and immunostimulants on the GM composition of rainbow trout Oncorhynchus mykiss (Walbaum) and investigated its association with blood parameters and disease resistance (against enteric red mouth disease (ERM) caused the bacterium Yersinia ruckeri). A total of 640 fish received either 1) basic fish feed without organic acids or immunostimulants, 2) fish feed with immunostimulants (β6glu…

Genome rearrangement distances and gene order phylogeny in gamma-Proteobacteria.

2005

Genome rearrangements have been studied in 30 gamma-proteobacterial complete genomes by comparing the order of a reduced set of genes on the chromosome. This set included those genes fulfilling several characteristics, the main ones being that an ortholog was present in every genome and that none of them had been acquired by horizontal gene transfer. Genome rearrangement distances were estimated based on either the number of breakpoints or the minimal number of inversions separating two genomes. Breakpoint and inversion distances were highly correlated, indicating that inversions were the main type of rearrangement event in gamma-Proteobacteria. In general, the progressive increase in seque…

Modeling the epidemiological history of plague in Central Asia: Palaeoclimatic forcing on a disease system over the past millennium

2010

Abstract Background Human cases of plague (Yersinia pestis) infection originate, ultimately, in the bacterium's wildlife host populations. The epidemiological dynamics of the wildlife reservoir therefore determine the abundance, distribution and evolution of the pathogen, which in turn shape the frequency, distribution and virulence of human cases. Earlier studies have shown clear evidence of climatic forcing on contemporary plague abundance in rodents and humans. Results We find that high-resolution palaeoclimatic indices correlate with plague prevalence and population density in a major plague host species, the great gerbil (Rhombomys opimus), over 1949-1995. Climate-driven models trained…

HLA-B27-restricted CD8 T cells derived from synovial fluids of patients with reactive arthritis and ankylosing spondylitis.

1993

Ankylosing spondylitis and seronegative spondylarthropathies such as Reiter's syndrome and reactive arthritis are strongly associated with HLA-B27. However, the mechanisms by which HLA-B27 is involved in disease susceptibility and pathogenesis are unknown. If the disease association is a consequence of HLA-B27's physiological function in antigen presentation, the disease should be mediated by cytotoxic T lymphocytes (CTLs) that recognise bacterial or self peptides presented by HLA-B27. Proof of this arthritogenic peptide model requires isolation of B27-restricted CD8 T cells from arthritic joints of patients with spondylarthropathies. An important question is whether "arthritogenic" bacteri…

HLA-B27-restricted cytotoxic T lymphocyte responses to arthritogenic enterobacteria or self-antigens are dominated by closely related TCRBV gene segm…

1996

Identification of the T-cell receptors (TCR) used by synovial cytotoxic T lymphocytes (CTL) of patients with reactive arthritis (ReA) may be crucial to better understanding the pathogenetic mechanism underlying the HLA-B27 association of spondylarthropathies. The authors, therefore, sequenced 25 TCRB chains from HLA-B27-restricted CD8+ CTL clones and two clonal lines specific for self- or Yersinia enterocolitica antigen isolated from synovial fluids of 3 HLA-B27+ patients with ReA and PBL of one healthy HLA-B27+ individual. Fourteen non-HLA-B27-restricted CTL served as controls. Both autoreactive and Y. enterocolitica specific HLA-B27-restricted CTL used a highly limited set of VB genes wit…

Enterobacterial Antigens with Tropism for Joint Structures and HLA-B27=Restricted Cytotoxic T-Cells in Reactive Arthritis

1995

In reactive arthritis (ReA), sterile synovitis is an immunological sequela following gastrointestinal or urogenital infection with facultatively intracellular bacteria (Yersinia, Salmonella, Shigella, Chlamydia). It is widely accepted now that the development of arthritis is closely related to the persistance of bacteria or bacterial antigens in extraarticular mucosal or lymphoid tissues (i.e. gut mucosa, gut associated lymphoid tissue, genitourinary mucosa); however, it is still unclear which host mechanisms are responsible for the poorer elimination of arthritis-causing microorganisms in those ReA patients. Bacterial components are also camed to the joints where they can be demonstrated i…

Identification of the Yersinia enterocolitica urease beta subunit as a target antigen for human synovial T lymphocytes in reactive arthritis.

1993

The local T-cell response to bacterial antigens is involved in the pathogenesis of reactive arthritis (ReA). Here, we have identified a 19-kDa antigen of Yersinia enterocolitica O:9 recognized by Yersinia-specific synovial fluid CD4+ T cells in two patients with Yersinia-induced ReA. N-terminal amino acid sequencing of this protein revealed that it was identical to the 19-kDa urease beta subunit of Y. enterocolitica O:9. This protein has previously been shown to be arthritogenic in preimmunized rats after intra-articular injection. Analysis of the T-cell response to this protein showed that it contains several T-cell epitopes, one of which cross-reacts with other enterobacteria not able to …

Persistence ofYersinia antigens in peripheral blood cells from patients withYersinia enterocolitica O:3 infection with or without reactive arthritis

1998

Objective To assess the persistence of bacterial antigens in peripheral blood cells from patients with Yersinia enterocolitica O:3-triggered reactive arthritis (ReA). Methods Peripheral blood samples were obtained from 20 patients with Y enterocolitica O:3 infection (11 with ReA and 9 without). These samples were studied by immunochemical techniques for the presence of Yersinia antigens at the beginning of infection and up to 4 years thereafter. Synovial fluid samples from 6 of the 11 ReA patients were also studied. Results The Yersinia antigens lipopolysaccharide and heat-shock protein (HSP) were detected in peripheral blood mononuclear cells and polymorphonuclear phagocytes from all patie…