- Lectin pathway factors in patients suffering from juvenile idiopathic arthritis. [Journal Article]
- ICImmunol Cell Biol 2017 Apr 13
- Both complement activation and certain infections (including those with Yersinia sp.) may contribute to the pathogenesis of juvenile idiopathic arthritis (JIA). We investigated factors specific for t...
Both complement activation and certain infections (including those with Yersinia sp.) may contribute to the pathogenesis of juvenile idiopathic arthritis (JIA). We investigated factors specific for the lectin pathway of complement: mannose-binding lectin (MBL), ficolins and associated serine protease-2 (MASP-2), in 144 patients and 98 controls. 106 patients had oligoarticular disease and 38 had polyarticular disease. In 51 patients (out of 133 tested), Yersinia-reactive antibodies were found (JIA Ye+ group). MBL deficiency was significantly more frequent in the JIA Ye+ group than in patients without Yersinia-reactive Abs or in controls. Median serum ficolin-2 level was significantly lower (and proportion of values deemed ficolin-2 insufficient greater) in JIA patients irrespective of their Yersinia antibody status. The minority (C) allele at -64 of the FCN2 gene was less frequent among JIA patients than among control subjects. No differences were found in the frequency of FCN3 gene +1637delC or MASP2 +359 A>G mutations nor for median values of serum ficolin-1, ficolin-3 or MASP-2. However, high levels of serum ficolin-3 were under-represented in patients, in contrast to MBL. MBL, ficolin-1, ficolin-2, ficolin-3 and MASP-2 were also readily detectable in synovial fluid samples but at a considerably lower level than in serum. Our findings suggest a possible role for the lectin pathway in the pathogenesis of JIA, perhaps secondary to a role in host defence, and indicate that investigations on the specificity of lectin pathway recognition molecules towards specific infectious agents in JIA might be fruitful.Immunology and Cell Biology accepted article preview online, 13 April 2017. doi:10.1038/icb.2017.31.
- Low prevalence of human enteropathogenic Yersinia spp. in brown rats (Rattus norvegicus) in Flanders. [Journal Article]
- PlosPLoS One 2017; 12(4):e0175648
- Brown rats (Rattus norvegicus) have been identified as potential carriers of Yersinia enterocolitica and Y. pseudotuberculosis, the etiological agents of yersiniosis, the third most reported bacteria...
Brown rats (Rattus norvegicus) have been identified as potential carriers of Yersinia enterocolitica and Y. pseudotuberculosis, the etiological agents of yersiniosis, the third most reported bacterial zoonosis in Europe. Enteropathogenic Yersinia spp. are most often isolated from rats during yersiniosis cases in animals and humans, and from rats inhabiting farms and slaughterhouses. Information is however lacking regarding the extent to which rats act as carriers of these Yersinia spp.. In 2013, 1088 brown rats across Flanders, Belgium, were tested for the presence of Yersinia species by isolation method. Identification was performed using MALDI-TOF MS, PCR on chromosomal- and plasmid-borne virulence genes, biotyping and serotyping. Yersinia spp. were isolated from 38.4% of the rats. Of these, 53.4% were designated Y. enterocolitica, 0.7% Y. pseudotuberculosis and 49.0% other Yersinia species. Two Y. enterocolitica possessing the virF-, ail- and ystA-gene were isolated. Additionally, the ystB-gene was identified in 94.1% of the other Y. enterocolitica isolates, suggestive for biotype 1A. Three of these latter isolates simultaneously possessed the ail-virulence gene. Significantly more Y. enterocolitica were isolated during winter and spring compared to summer. Based on our findings we can conclude that brown rats are frequent carriers for various Yersinia spp., including Y. pseudotuberculosis and (human pathogenic) Y. enterocolitica which are more often isolated during winter and spring.
- Salicylidene acylhydrazides and hydroxyquinolines act as inhibitors of type three secretion systems in Pseudomonas aeruginosa by distinct mechanisms. [Journal Article]
- AAAntimicrob Agents Chemother 2017 Apr 10
- Type three secretion systems (T3SS) are major virulence factors in Gram-negative bacteria. Pseudomonas aeruginosa expresses two T3SS, namely an injectisome (iT3SS) translocating effector proteins in ...
Type three secretion systems (T3SS) are major virulence factors in Gram-negative bacteria. Pseudomonas aeruginosa expresses two T3SS, namely an injectisome (iT3SS) translocating effector proteins in the host cell cytosol, and a flagellum (fT3SS) insuring bacterial motility. Inhibiting these systems is an appealing therapeutic strategy for acute infections. This study examines the protective effects of the salicylidene acylhydrazide INP0341 and of the hydroxyquinoline INP1750 (previously described as T3SS inhibitors in other species) towards cytotoxic effects of P. aeruginosain vitro Both compounds reduced cell necrosis and inflammasome activation induced by reference strains or clinical isolates expressing T3SS toxins or only the translocation apparatus. INP0341 inhibited iT3SS transcriptional activation, including in strains with constitutive iT3SS expression, and reduced the total expression of toxins, suggesting it targets iT3SS gene transcription. INP1750 inhibited toxin secretion and flagellar motility and impaired the activity the YscN ATPase from Yersinia pseudotuberculosis (homologous to the ATPase present in the basal body of P. aeruginosa iT3SS and fT3SS), suggesting it rather targets a T3SS core constituent with high homology among iT3SS and fT3SS. This mode of action is similar to that previously described for INP1855, another hydroxyquinoline, against P. aeruginosa. Thus, although acting by different mechanisms, INP0341 and INP1750 appear as useful inhibitors of the virulence of P. aeruginosa. Hydroxyquinolines may have a broader spectrum of activity by the fact they act upon two virulence factors (iT3SS and fT3SS).
- [Erythema nodosum : a panniculitis of diverse origins]. [Review]
- RMRev Med Liege 2017; 72(1):43-44
- Erythema nodosum is an acute nodular panniculitis, mainly affecting young women. Diverse etiologies are evoked, but the most frequent are sarcoidosis (Löfgren syndrome), streptococcal infections, yer...
Erythema nodosum is an acute nodular panniculitis, mainly affecting young women. Diverse etiologies are evoked, but the most frequent are sarcoidosis (Löfgren syndrome), streptococcal infections, yersiniosis and inflammatory enteropathies. Antalgic drugs and rest are usually adequate in this condition, which is spontaneously of favourable evolution. Treatment of the cause is open to discussion, considering their lack of effect on the evolution of erythema nodosum.
- A study of single nucleotide polymorphism in the ystB gene of Yersinia enterocolitica strains isolated from various wild animal species. [Journal Article]
- AAAnn Agric Environ Med 2017 Mar 01; 24(1):56-61
- CONCLUSIONS: The proposed HRM method could be used to analyze Y. enterocolitica biotype 1A strains isolated from different sources, including humans.
- Yersinia pseudotuberculosis supports Th17 differentiation and limits de novo regulatory T cell induction by directly interfering with T cell receptor signaling. [Journal Article]
- CMCell Mol Life Sci 2017 Apr 04
- Adaptive immunity critically contributes to control acute infection with enteropathogenic Yersinia pseudotuberculosis; however, the role of CD4(+) T cell subsets in establishing infection and allowin...
Adaptive immunity critically contributes to control acute infection with enteropathogenic Yersinia pseudotuberculosis; however, the role of CD4(+) T cell subsets in establishing infection and allowing pathogen persistence remains elusive. Here, we assessed the modulatory capacity of Y. pseudotuberculosis on CD4(+) T cell differentiation. Using in vivo assays, we report that infection with Y. pseudotuberculosis resulted in enhanced priming of IL-17-producing T cells (Th17 cells), whereas induction of Foxp3(+) regulatory T cells (Tregs) was severely disrupted in gut-draining mesenteric lymph nodes (mLNs), in line with altered frequencies of tolerogenic and proinflammatory dendritic cell (DC) subsets within mLNs. Additionally, by using a DC-free in vitro system, we could demonstrate that Y. pseudotuberculosis can directly modulate T cell receptor (TCR) downstream signaling within naïve CD4(+) T cells and Tregs via injection of effector molecules through the type III secretion system, thereby affecting their functional properties. Importantly, modulation of naïve CD4(+) T cells by Y. pseudotuberculosis resulted in an enhanced Th17 differentiation and decreased induction of Foxp3(+) Tregs in vitro. These findings shed light to the adjustment of the Th17-Treg axis in response to acute Y. pseudotuberculosis infection and highlight the direct modulation of CD4(+) T cell subsets by altering their TCR downstream signaling.
- Yersinia spp. in Wild Rodents and Shrews in Finland. [Journal Article]
- VBVector Borne Zoonotic Dis 2017; 17(5):303-311
- Yersinia enterocolitica and Yersinia pseudotuberculosis are important zoonotic bacteria causing human enteric yersiniosis commonly reported in Europe. All Y. pseudotuberculosis strains are considered...
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 mammals as a reservoir of enteropathogenic Yersinia spp. is still obscure. In this study, the presence of Yersinia spp. was examined from 1840 wild small mammals, including voles, mice, and shrews, trapped in Finland during a 7-year period. We isolated seven Yersinia species. Y. enterocolitica was the most common species, isolated from 8% of the animals; while most of these isolates represented nonpathogenic biotype 1A, human pathogenic bioserotype 2/O:9 was also isolated from a field vole. Y. pseudotuberculosis of bioserotype 1/O:2 was isolated from two shrews. The ail gene, which is typically only found in the isolates of biotypes 1B and 2-5 associated with yersiniosis, was frequently (23%) detected in the nonpathogenic isolates of biotype 1A and sporadically (6%) in Yersinia kristensenii isolates. Our results suggest that wild small mammals, especially voles, may serve as carriers for ail-positive Y. enterocolitica 1A and Y. kristensenii. We also demonstrate that voles and shrews sporadically excrete pYV-positive Y. enterocolitica 2/O:9 and Y. pseudotuberculosis 1/O:2, respectively, in their feces and, thus, can serve as a contamination source for vegetables by contaminating the soil.
- A study on the efficacy of the recombinant Yersinia adhesin A vaccine against yersiniosis in the early phase. [Journal Article]
- JVJ Vet Med Sci 2017 Mar 20
- Yersinia pseudotuberculosis (Y. ptb) is a zoonotic pathogenic bacterial species of the family Enterobacteriaceae and causes yersiniosis, an acute intestinal infection in humans and animals. Y. ptb is...
Yersinia pseudotuberculosis (Y. ptb) is a zoonotic pathogenic bacterial species of the family Enterobacteriaceae and causes yersiniosis, an acute intestinal infection in humans and animals. Y. ptb is often implicated in lethal epidemics in zoo animals and reductions in the breeding population, but a valid prevention method has not been established. Therefore, this study aimed to develop a vaccine for yersiniosis control. The immunogenicity of one of the adhesion factors involved in pathogenic mechanisms of Y. ptb, Yersinia adhesin A (YadA), was investigated. BALB/c mice were divided into 3 groups: in group 1, mice received insoluble recombinant YadA (rYadA) produced in genetically engineered Escherichia coli (100 μg/dose); in group 2, mice received inactivated Y. ptb with strong expression of YadA (20 mg/dose); and in group 3, mice received phosphate-buffered saline (0.2 ml/dose). All interventions were administered subcutaneously twice at an interval of 1 week. One week after the second administration, Y. ptb (10(7) cells/mouse) was inoculated orally. As a result, the survival rate was 100% in group 1, 60% in group 2, and 0% in group 3. The anti-YadA antibody titer increased in a stepwise fashion in groups 1 and 2. The present study results suggest that rYadA shows promise as a protective antigen against yersiniosis. This study concluded that vaccination against Y. ptb may become available as a new method to prevent lethal epidemics in animals.
- Susceptibility to rifaximin and other antimicrobials of bacteria isolated in patients with acute gastrointestinal infections in Southeast Mexico. [Journal Article]
- RGRev Gastroenterol Mex 2017 Mar 12
- CONCLUSIONS: The data of the present study were similar to those of a previous study carried out in Mexico City: susceptibility to RIF in > 98% of the bacterial strains and a high frequency of resistance to several common antimicrobials.
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- Reactive Arthritis. [Review]
- IDInfect Dis Clin North Am 2017 Mar 11
- Reactive arthritis is classified as a spondyloarthropathy. Current concepts of disease suggest an infectious trigger, followed by inflammatory arthritis. Several mechanisms have been proposed to expl...
Reactive arthritis is classified as a spondyloarthropathy. Current concepts of disease suggest an infectious trigger, followed by inflammatory arthritis. Several mechanisms have been proposed to explain the interaction of host susceptibility and microorganism. Diagnosis relies on a compatible clinical syndrome and microbiologic confirmation of the pathogen. Antibiotic therapy seems useful in Chlamydia-triggered arthritis. The role of antibiotics in arthritis triggered by enteric pathogens is less clear. The role of tumor necrosis factor alpha inhibitors in therapy is evolving. Many patients have a course limited to a few months, but others experience extraarticular disease and more prolonged courses.