Identification des Pseudomonas sp. par spectrométrie de masse type MALDI-TOF

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fbl-Typing of Staphylococcus lugdunensis: A Frontline Tool for Epidemiological Studies, but Not Predictive of Fibrinogen Binding Ability

Staphylococcus lugdunensis is increasingly recognized as a potent pathogen, responsible for severe infections with an outcome resembling that of Staphylococcus aureus. Here, we developed and evaluated a tool for S. lugdunensis typing, using DNA sequence analysis of the repeat-encoding region (R-domain) in the gene encoding the fibrinogen (Fg)-binding protein Fbl (fbl-typing). We typed 240 S. lugdunensis isolates from various clinical and geographical origins. The length of the R-domain ranged from 9 to 52 repeats. fbl-typing identified 54 unique 18-bp repeat sequences and 92 distinct fbl-types. The discriminatory power of fbl-typing was higher than that of multilocus sequence typing (MLST) and equivalent to that of tandem repeat sequence typing. fbl-types could assign isolates to MLST clonal complexes with excellent predictive power. The ability to promote adherence to immobilized human Fg was evaluated for 55 isolates chosen to reflect the genetic diversity of the fbl gene. We observed no direct correlation between Fg binding ability and fbl-types. However, the lowest percentage of Fg binding was observed for isolates carrying a 5′-end frameshift mutation of the fbl gene and for those harboring fewer than 43 repeats in the R-domain. qRT-PCR assays for some isolates revealed no correlation between fbl gene expression and Fg binding capacity. In conclusion, this study shows that fbl-typing is a useful tool in S. lugdunensis epidemiology, especially because it is an easy, cost-effective, rapid and portable method (http://fbl-typing.univ-rouen.fr/). The impact of fbl polymorphism on the structure of the protein, its expression on the cell surface and in virulence remains to be determined

Identification des Pseudomonas sp. par spectrométrie de masse type MALDI-TOF

International audienc

Diversité au sein du clone hypervirulent "normand" de Neisseria meningitidis B:14:P1.7,16/ST32 : des souches plus virulentes que d'autres ?

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Diversité au sein du clone hypervirulent "normand" de Neisseria meningitidis B:14:P1.7,16/ST32 : des souches plus virulentes que d'autres ?

International audienc

Prevalence and diversity of Clostridium difficile strains in infants

International audienceDuring early infancy asymptomatic intestinal colonization by Clostridium difficile is frequent. To update information on infant colonization prevalence and to characterize infant strains, in terms of their virulence factors and their phylogenetic diversity, a prospective screening of C. difficile in the stools of infants 0 to 2 years old was conducted at Jean Verdier Hospital (Hopital Jean Verdier) over an 18 month period. C. difficile was screened by toxigenic culture, and molecular characterization was performed by PCR-ribotyping and multilocus sequence typing (MLST). The overall C. difficile colonization prevalence was 33.7% (99/294). The colonization rate by a toxigenic strain was 7.1 % (21/294). Community-acquired C. difficile accounted for 66.7% (66/99) of cases. Molecular typing was performed on 90 isolates from Jean Verdier Hospital and 8 additional isolates from another hospital in Versailles (Centre Hospitalier de Versailles). Among these isolates, 23 were toxigenic (21 tcdA(+) /tcdB(+) and 2 tcdA(-)/tcdB(+)). All the isolates were negative for the binary toxin genes. Seventeen PCR ribotypes (PRs) were identified, with five PRs accounting for 82.7% (81/98) of the isolates. MLST generated 15 different sequence types (STs). The predominant genotype, PRJV11-ST38 (33.7%), included only non-toxigenic strains. Toxigenic strains were distributed in eight genotypes. Neither PR027-ST3, nor PR078/126-ST49 were identified but some PRs/STs corresponded to well-known adult infectious strains. These results indicate that infants are widely colonized by non-toxigenic strains. However, toxigenic adult infectious strains circulate in asymptomatic infants even in the community; thus, infants may be a reservoir for adult infectious strains

Presence of respiratory viruses in ICU patients with community acquired-pneumonia (CAP): a one-year restrospective single center study

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Life-Threatening Pneumopathy and U urealyticum in a STAT3-Deficient Hyper-IgE Syndrome Patient

International audienceA deficiency in signal transducer and activator of transcription 3 (STAT3) is responsible for autosomal dominant hyperimmunoglobulin E syndrome, an immunodeficiency syndrome causing Staphylococcus aureus, Streptococcus pneumonia, Haemophilus influenzae, and, rarely, Pseudomonas aeruginosa and Aspergillus sp infections. Currently, intracellular pathogens are not targeted in the management of severe infections. The pathophysiologic mechanism of hyperimmunoglobulin E syndrome immunodeficiency has recently been linked to a disorder in the T helper 17 pathway and disruption of the interleukin -23/interleukin-17 axis. We report an unusual case of severe pleuropneumopathy by Ureaplasma urealyticum in a teenage girl with STAT3-deficient hyperimmunoglobulin E syndrome (STAT3 HIES). A previous case of severe lung infection by Mycoplasma pneumoniae has already been described in a STAT3-deficient patient, but U urealyticum has never been reported in patients with STAT3 HIES. After a review of the literature, it seems that the specific immunodeficiency pathway of STAT3 HIES exposes STAT3 HIES patients to Ureaplasma lung infections because the pathophysiology of STAT3 HIES and Ureaplasma is based on STAT3 and T helper 17 cells

Multiple-Locus Variable Number Tandem Repeat (VNTR) Analysis (MLVA) : a helpful tool for subtyping Staphylococcus lugdunensis

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