National Reference Center for Staphylococci

Sainte-Foy-lès-Lyon, France

National Reference Center for Staphylococci

Sainte-Foy-lès-Lyon, France

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Price L.B.,Translational Genomics Research Institute TGen | Stegger M.,Statens Serum Institute | Hasman H.,Technical University of Denmark | Aziz M.,Translational Genomics Research Institute TGen | And 32 more authors.
mBio | Year: 2012

Since its discovery in the early 2000s, methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 398 (CC398) has become a rapidly emerging cause of human infections, most often associated with livestock exposure. We applied whole-genome sequence typing to characterize a diverse collection of CC398 isolates (n = 89), including MRSA and methicillin-susceptible S. aureus (MSSA) from animals and humans spanning 19 countries and four continents. We identified 4,238 single nucleotide polymorphisms (SNPs) among the 89 core genomes. Minimal homoplasy (consistency index = 0.9591) was detected among parsimony-informative SNPs, allowing for the generation of a highly accurate phylogenetic reconstruction of the CC398 clonal lineage. Phylogenetic analyses revealed that MSSA from humans formed the most ancestral clades. The most derived lineages were composed predominantly of livestock-associated MRSA possessing three different staphylococcal cassette chromosome mec element (SCCmec) types (IV, V, and VII-like) including nine subtypes. The human-associated isolates from the basal clades carried phages encoding human innate immune modulators that were largely missing among the livestock-associated isolates. Our results strongly suggest that livestock-associated MRSA CC398 originated in humans as MSSA. The lineage appears to have undergone a rapid radiation in conjunction with the jump from humans to livestock, where it subsequently acquired tetracycline and methicillin resistance. Further analyses are required to estimate the number of independent genetic events leading to the methicillin-resistant sublineages, but the diversity of SCCmec subtypes is suggestive of strong and diverse antimicrobial selection associated with food animal production. © 2012 Price et al.

Couve-Deacon E.,University of Limoges | Couve-Deacon E.,French Institute of Health and Medical Research | Tristan A.,Hospices Civils de Lyon | Tristan A.,National Reference Center for Staphylococci | And 15 more authors.
Emerging Infectious Diseases | Year: 2016

Staphylococcus aureus strains that produce Panton-Valentine leukocidin are known to cause community infections. We describe an outbreak of skin abscesses caused by Panton-Valentine leukocidin–producing methicillin-susceptible S. aureus (clonal complex 121) in a professional rugby team in France during July 2010–February 2011. Eight team members were carriers; 7 had skin abscesses. © 2016, Centers for Disease Control and Prevention (CDC). All rights reseved.

PubMed | National Reference Center for Staphylococci, University Putra Malaysia, Laboratorio Aziendale Of Microbiologia E Virologia, Laiko General Hospital and 19 more.
Type: Journal Article | Journal: Journal of global antimicrobial resistance | Year: 2016

The antibiotic susceptibility and molecular epidemiology of Panton-Valentine leukocidin (PVL)-positive meticillin-resistant Staphylococcus aureus (MRSA) isolates reported from 17 countries in the Americas, Europe and, Australia-Asia were analysed. Among a total of 3236 non-duplicate isolates, the lowest susceptibility was observed to erythromycin in all regions. Susceptibility to ciprofloxacin showed large variation (25%, 75% and 84% in the Americas, Europe and Australia-Asia, respectively). Two vancomycin-intermediate PVL-positive MRSA isolates were reported, one from Hong Kong and the other from The Netherlands. Resistance to trimethoprim/sulfamethoxazole and linezolid was <1%. Among 1798 MRSA isolates from 13 countries that were tested for the requested 10 non--lactam antibiotics, 49.4% were multisusceptible. However, multiresistant isolates (resistant to at least three classes of non--lactam antibiotics) were reported from all regions. Sequence type 30 (ST30) was reported worldwide, whereas ST80 and ST93 were exclusive to Europe and Australia, respectively. USA300 and related clones (ST8) are progressively replacing the ST80 clone in several European countries. Eight major clusters were discriminated by multilocus variable-number tandem repeat assay (MLVA), showing a certain geographic specificity. PVL-positive MRSA isolates frequently remain multisusceptible to non--lactam agents, but multiresistance is already prevalent in all regions. Surveillance of MRSA susceptibility patterns should be monitored to provide clinicians with the most current information regarding changes in resistance patterns.

Rasigade J.-P.,University of Lyon | Rasigade J.-P.,National Reference Center for Staphylococci | Rasigade J.-P.,Northern Hospital Group | Trouillet-Assant S.,University of Lyon | And 19 more authors.
PLoS ONE | Year: 2013

Epidemic community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is associated with more severe and acute forms of osteomyelitis than healthcare-associated (HA-) MRSA. Although S. aureus is now recognized as a facultative intracellular pathogen, the contribution of osteoblast invasion by CA-MRSA to the pathogenesis of osteomyelitis is unknown. Using an ex vivo model of intracellular infection of human osteoblasts, we demonstrated that CA-MRSA strains of diverse lineages share an enhanced ability to kill infected osteoblasts compared to HA-MRSA. Cytotoxicity comparisons of CA-MRSA isogenic deletion mutants revealed that phenol-soluble modulins (PSMs), a class of membrane-damaging exoproteins that are expressed at higher levels in CA-MRSA than in HA-MRSA, are involved in this osteoblast killing, whereas other major CA-MRSA virulence determinants, the Panton-Valentine leukocidin and alpha-toxin, are not involved. Similarly, functional agr and sarA regulators, which control the expression of PSMs and alpha-toxin, were required for the expression of the intracellular cytotoxic phenotype by CA-MRSA, whereas the saeRS regulator, which controls the expression of alpha-toxin but not PSMs, had no impact on cytotoxicity. Finally, PSM transcript levels determined by quantitative reverse-transcriptase PCR were significantly higher in CA-MRSA than in HA-MRSA strains and associated with cell damage in MRSA-infected osteoblasts. These findings provide new insights into the pathogenesis of severe CA-MRSA osteomyelitis and unravel a novel virulence strategy of CA-MRSA, based on the invasion and subsequent killing of osteoblasts by PSMs acting as intracellular toxins. © 2013 Rasigade et al.

PubMed | University Hospital of Tuebingen, Public Health England, National Reference Center for Staphylococci, Servei Of Microbiologia Hospital Universitari Germans Trias jol and 4 more.
Type: | Journal: The Journal of antimicrobial chemotherapy | Year: 2016

MRSA is a therapeutic concern worldwide, and a major agent of community-acquired skin and soft tissue infections (CA-SSTIs). While the US epidemiology of MRSA in CA-SSTIs is well described and reports the high prevalence of the USA300 clone, data on the European situation are lacking.To determine the prevalence and clonal characteristics of MRSA in CA-SSTIs in seven European emergency departments.From April to June 2015, patients presenting to the tertiary hospital emergency department with a Staphylococcus aureus CA-SSTI were prospectively enrolled. S. aureus isolates were characterized by antimicrobial susceptibility testing, detection of Panton-Valentine leucocidin encoding genes and spa-typing, MLST and/or DNA microarray.Two-hundred and five cases of S. aureus-associated CA-SSTIs were included, comprising folliculitis, furuncles, abscesses, paronychia, impetigo, carbuncles and cellulitis. Of the 205 cases, we report an MRSA prevalence rate of 15.1%, with a north (0%) to south (29%) increasing gradient. Fifty-one isolates were Panton-Valentine leucocidin-positive (24.9%), whether MSSA or MRSA, with a heterogeneous distribution between countries. Clonal distribution of MSSA and MRSA showed high diversity, with no predominant circulating clone and no archetypical USA300 CA-MRSA clone.This original prospective multicentre study highlights stark differences in European MRSA epidemiology compared with the USA, and that the USA300 CA-MRSA clone is not predominant among community-infected patients in Europe.

Simoes P.M.,University of Lyon | Simoes P.M.,Northern Hospital Group | Simoes P.M.,National Reference Center for Staphylococci | Rasigade J.-P.,University of Lyon | And 17 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2013

Multiresistant Staphylococcus capitis pulsotype NRCS-A has been reported to be a major pathogen causing nosocomial bacteremia in preterm infants. We report that the NRCS-A strain CR01 harbors a novel 60.9-kb composite staphylococcal cassette chromosome mec (SCCmec) element, composed of an SCCmec with strong homologies to Staphylococcus aureus ST398 SCCmec and of an SCCcad/ars/cop harboring resistance genes for cadmium, arsenic, and copper. Whole-genome-based comparisons of published S. capitis strains suggest that strain CR01 acquired the two elements independently. Copyright © 2013 White.

Tattevin P.,Pontchaillou University Hospital | Tattevin P.,University of Rennes 1 | Saleh-Mghir A.,University of Versailles | Saleh-Mghir A.,Raymond Poincare University Hospital | And 10 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2013

Concerns have recently emerged about the potency and the quality of generic vancomycin (VAN) products approved for use in humans, based on experiments in a neutropenic mouse thigh infection model. However, other animal models may be more appropriate to decipher the bactericidal activities of VAN generics in vivo and to predict their efficacy in humans. We aimed to compare the bactericidal activities of six generic VAN products currently used in France (Mylan and Sandoz), Spain (Hospira), Switzerland (Teva), and the United States (Akorn-Strides and American Pharmaceutical Products [APP]) in a rabbit model of aortic valve endocarditis induced by 8×107 CFU of methicillin-resistant Staphylococcus aureus (MRSA) strain COL (VAN MIC, 1.5 μg/ml). In vitro, there were no significant differences in the time-kill curve studies performed with the six generic VAN products. Ten rabbits in each group were treated with intravenous (i.v.) VAN, 60 mg/kg of body weight twice a day (b.i.d.) for 4 days. Mean peak serum VAN levels, measured 45 min after the last injection, ranged from 35.5 (APP) to 45.9 μg/ml (Teva). Mean trough serum VAN levels, measured 12 h after the last injection, ranged from 2.3 (Hospira) to 9.2 (APP) μg/ml. All generic VAN products were superior to controls (no treatment) in terms of residual organisms in vegetations (P<0.02 for each comparison) and in the spleen (P<0.005 for each comparison). Pairwise comparisons of generic VAN products found no significant differences. In conclusion, a stringent MRSA endocarditis model found no significant differences in the bactericidal activities of six generic VAN products currently used in Europe and America. Copyright © 2013, American Society for Microbiology.

Butin M.,Ecole Normale Superieure de Lyon | Martins-Simoes P.,Ecole Normale Superieure de Lyon | Martins-Simoes P.,National Reference Center for Staphylococci | Picaud J.C.,Northern Hospital Group | And 11 more authors.
Journal of Antimicrobial Chemotherapy | Year: 2015

Objectives: The Staphylococcus capitis clone NRCS-A has recently been described as a frequent cause of late-onset sepsis (LOS) in pre-term neonates worldwide. Representatives of this clone exhibit non-susceptibility to vancomycin, the first-line agent used in LOS. Cases of prolonged S. capitis LOS despite vancomycin treatment have been reported. We investigated whether NRCS-A strains exhibit faster adaptation to vancomycin pressure as compared with other staphylococci. Methods: Strains of S. capitis NRCS-A, S. capitis non-NRCS-A and Staphylococcus epidermidis (n=2 each, all with vancomycin MICs ≤2 mg/L) and the prototype vancomycin-heteroresistant Staphylococcus aureus Mu3 were subcultured daily for 15 days with 0.25-32 mg/L vancomycin. Regression coefficients of daily log2 MICs on time were used to estimate the kinetics of resistance development. Changes in bacterial cell-wall thickness were measured by transmission electron microscopy. To assess the stability of resistance and the emergence of cross-resistance, vancomycin, teicoplanin, daptomycin and linezolid MICs were measured before and after vancomycin treatment, as well as after nine additional subcultures without antibiotics. Results: All strains developed a stable resistance to vancomycin, but this occurred significantly faster in S. capitis NRCS-A than in S. capitis non-NRCS-A (P<0.001) and other species (P<0.0001). Vancomycin resistance in S. capitis NRCS-A was associated with significant cell-wall thickening and an increase in MICs of daptomycin and teicoplanin, but not linezolid. Conclusions: S. capitis NRCS-A rapidly adapts to vancomycin pressure as compared with potential niche competitors, a feature that might contribute to its success in neonatal ICUs where vancomycin is widely prescribed. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

Stegger M.,Statens Serum Institute | Stegger M.,Translational Genomics Research Institute | Liu C.M.,Translational Genomics Research Institute | Larsen J.,Statens Serum Institute | And 16 more authors.
PLoS ONE | Year: 2013

Staphylococcus aureus clonal complex 398 (CC398) isolates cluster into two distinct phylogenetic clades based on single-nucleotide polymorphisms (SNPs) revealing a basal human clade and a more derived livestock clade. The scn and tet(M) genes are strongly associated with the human and the livestock clade, respectively, due to loss and acquisition of mobile genetic elements. We present canonical single-nucleotide polymorphism (canSNP) assays that differentiate the two major host-associated S. aureus CC398 clades and a duplex PCR assay for detection of scn and tet (M). The canSNP assays correctly placed 88 S. aureus CC398 isolates from a reference collection into the human and livestock clades and the duplex PCR assay correctly identified scn and tet(M). The assays were successfully applied to a geographically diverse collection of 272 human S. aureus CC398 isolates. The simple assays described here generate signals comparable to a whole-genome phylogeny for major clade assignment and are easily integrated into S. aureus CC398 surveillance programs and epidemiological studies. © 2013 Stegger et al.

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