Search results for "Yersinia"
showing 10 items of 42 documents
Co-existence of virulence factors and antibiotic resistance in new Klebsiella pneumoniae clones emerging in south of Italy
2018
Abstract Background Endemic presence of Klebsiella pneumoniae resistant to carbapenem in Italy has been due principally to the clonal expansion of CC258 isolates; however, recent studies suggest an ongoing epidemiological change in this geographical area. Methods 50 K. pneumoniae strains, 25 carbapenem-resistant (CR-Kp) and 25 susceptible (CS-Kp), collected from march 2014 to march 2016 at the Laboratory of Bacteriology of the Paolo Giaccone Polyclinic University hospital of Palermo, Italy, were characterized for antibiotic susceptibility and fully sequenced by next generation sequencing (NGS) for the in silico analysis of resistome, virulome, multi-locus sequence typing (MLST) and core sin…
A 5,000-year-old hunter-gatherer already plagued by Yersinia pestis.
2021
Summary A 5,000-year-old Yersinia pestis genome (RV 2039) is reconstructed from a hunter-fisher-gatherer (5300–5050 cal BP) buried at Riņņukalns, Latvia. RV 2039 is the first in a series of ancient strains that evolved shortly after the split of Y. pestis from its antecessor Y. pseudotuberculosis ∼7,000 years ago. The genomic and phylogenetic characteristics of RV 2039 are consistent with the hypothesis that this very early Y. pestis form was most likely less transmissible and maybe even less virulent than later strains. Our data do not support the scenario of a prehistoric pneumonic plague pandemic, as suggested previously for the Neolithic decline. The geographical and temporal distributi…
Yersiniaspp. in Wild Rodents and Shrews in Finland
2017
Yersinia enterocolitica and Yersinia pseudotuberculosis are important zoonotic bacteria causing human enteric yersiniosis commonly reported in Europe. All Y. pseudotuberculosis strains are considered pathogenic, while Y. enterocolitica include both pathogenic and nonpathogenic strains which can be divided into six biotypes (1A, 1B, and 2-5) and about 30 serotypes. The most common types causing yersiniosis in Europe are Y. enterocolitica bioserotypes 4/O:3 and 2/O:9. Strains belonging to biotype 1A are considered as nonpathogenic because they are missing important virulence genes like the attachment-invasion-locus (ail) gene in the chromosome and the virulence plasmid. The role of wild small…
Diversity, virulence, and antimicrobial resistance of the KPC-producing Klebsiella pneumoniae ST307 clone
2017
ABSTRACT : The global spread of Klebsiella pneumoniae producing Klebsiella pneumoniae carbapenemase (KPC) has been mainly associated with the dissemination of high-risk clones. In the last decade, hospital outbreaks involving KPC-producing K. pneumoniae have been predominantly attributed to isolates belonging to clonal group (CG) 258. However, results of recent epidemiological analysis indicate that KPC-producing sequence type (ST) 307, is emerging in different parts of the world and is a candidate to become a prevalent high-risk clone in the near future. Here we show that the ST307 genome encodes genetic features that may provide an advantage in adaptation to the hospital environment and t…
A case of infective colitis due to Yersinia enterocolitica complicated by microliver abscesses mimicking multiple liver occult metastases: a case rep…
2021
Abstract Background We report an unusual case of infective colitis by Yersinia enterocolitica complicated by microliver abscesses mimicking multiple liver metastases in a 79 yr old female without any risk factors for bacteriaemia by this pathogen. Case presentation The patient was admitted to the Internal Medicine with Stroke Care ward of University Policlinico “P. Giaccone” in Palermo because of the appearance of diarrhoea. After the antimicrobial treatment for infective colitis, the clinicians observed a persistently increased white blood cells (WBC) count and multiple hepatic lesions; after having excluded any neoplastic disease and inflammatory bowel disease (IBD), blood cultures positi…
MHC-unrestricted recognition of bacteria-infected target cells by human CD8+ cytotoxic T lymphocytes.
1992
Abstract A CD8 + αβTCR + T cell clone (A35) was isolated from the synovial fluid of a patient with postenteric reactive arthritis caused by Yersinia enterocolitica . This clone efficiently killed autologous and allogeneic target cells that had been preincubated with live but not with heat-killed bacteria. There was no restriction by polymorphic parts of HLA-A, -B. or -C molecules and a HLA class II-deficient mutant cell line was lysed as efficiently as its normal counterpart, whereas infected HLA class I-deficient cells (Daudi cells) were not. The clone showed crossreaction between Yersinia enterocolitica , Escherichia coli , Pseudomonas aeruginosa , and Streptococcus pyogenes , but did not…
Synovial fluid-derivedYersinia-reactive T cells responding to human 65-kDa heat-shock protein and heat-stressed antigen-presenting cells
1991
Humoral and cellular immune reactions to heat-shock proteins have been implicated in the pathogenesis of arthritis. Heat-shock proteins occur in bacteria as well as all eukaryotes and have been highly conserved during evolution. Cross-reactivity between bacterial and human heat-shock proteins induced at the site of inflammation may underlie the pathogenesis of some forms of arthritis. In order to test this hypothesis, we raised and cloned a Yersinia-specific T cell line from the synovial fluid lymphocytes of a patient with Yersinia-induced reactive arthritis. From this line we obtained a CD4+ T cell clone that proliferated in response to Yersinia antigens and both to the mycobacterial and t…
Multiclonal Synovial T Cell Response toYersinia enterocoliticain Reactive Arthritis: TheYersinia61-kDa Heat-Shock Protein Is Not the Major Target Ant…
1993
The T cell response to bacterial antigens plays a major role in the pathogenesis of reactive arthritis (ReA) following enteric infections with Yersinia enterocolitica. To study the antigen specificity of the T cells at the site of inflammation, the response of cloned T cells from the synovial fluid of 2 patients with ReA to partially purified antigens of Yersinia enterocolitica was determined. The clones showed different patterns of response to various fractions, indicating a multiclonal response to Yersinia antigens, and these specificities differed in the 2 patients. Some T cells were specific for Y. enterocolitica; some cross-reacted with other enterobacteria. Proteins of 14 and 19 kDa c…
Predominance of Th1-type T cells in synovial fluid of patients with Yersinia-induced reactive arthritis
1992
The pathogenetic mechanisms underlying the development of reactive arthritis and the functional capacities of synovial T cells specific for Yersinia enterocolitica are still unclear. In this study we have determined the cytokine secretion patterns of 24 CD4+ synovial fluid (SF)-derived T cell clones from 2 patients with Yersinia-induced reactive arthritis, 16 clones specific for different Yersinia antigens and 8 clones as controls. The clones specific for Yersinia antigens predominantly belong to the T helper cell 1 (Th1) subset with production of interferon (IFN)-gamma and interleukin (IL)-2, but no IL-4, whereas SF T cells not reactive with Yersinia antigens produce IL-2, IL-4 and IFN-gam…
Stimulation of synovial fluid mononuclear cells with the human 65-kD heat shock protein or with live enterobacteria leads to preferential expansion o…
1992
SUMMARY T lymphocyte responses to heterologous or self 65-kD heat shock protein (hsp) have been implicated in the pathogenesis of various forms of arthritis. To delineate the relationship of 65-kD hsp to different synovial fluid (SF) T cell subsets, we stimulated synovial fluid (SFMC) and peripheral blood mononuclear cells (PBMC) from patients with different inflammatory rheumatic diseases and from healthy controls with human or mycobacterial 65-kD hsp, tetanus toxoid (TT), heat-killed or live Yersinia enterocotitica. Phenotyping of the resulting T cell lines revealed an increase of up to 97% TCR-γδ+ lymphocytes in the 65-kD hsp-stimulatcd SF-derived lines. This expansion of TCR-γδ+ cells w…