6 research outputs found
Fatal Meningitis from Shiga ToxinâProducing Escherichia coli in 2 Full-Term Neonates, France
We report fatal meningitis in 2 neonates in France caused by Shiga toxin 1âproducing Escherichia coli. Virulence factors capsular K1 antigen and salmochelin were present in both strains, potentially representing a new hybrid pathotype. Clinicians should remain aware of emerging pathotypes and design therapeutic strategies for neonatal E. coli infections
Genome sequencing of strains of the most prevalent clonal group of O1:K1:H7 Escherichia coli that causes neonatal meningitis in France
Abstract Background To describe the temporal dynamics, molecular characterization, clinical and ex vivo virulence of emerging O1:K1 neonatal meningitis Escherichia coli (NMEC) strains of Sequence Type complex (STc) 95 in France. The national reference center collected NMEC strains and performed whole genome sequencing (WGS) of O1:K1 STc95 NMEC strains for phylogenetic and virulence genes content analysis. Data on the clinical and biological features of patients were also collected. Ex vivo virulence was assessed using the Dictyostelium discoideum amoeba model. Results Among 250 NMEC strains collected between 1998 and 2015, 38 belonged to O1:K1 STc95. This clonal complex was the most frequently collected after 2004, representing up to 25% of NMEC strains in France. Phylogenetic analysis demonstrated that most (74%) belonged to a cluster designated D-1, characterized by the adhesin FimH30. There is no clinical data to suggest that this cluster is more pathogenic than its counterparts, although it is highly predominant and harbors a large repertoire of extraintestinal virulence factors, including a pS88-like plasmid. Ex vivo virulence model showed that this cluster was generally less virulent than STc95 reference strains of O45S88:H7 and O18:H7 serotypes. However, the model showed differences between several subclones, although they harbor the same known virulence determinants. Conclusions The emerging clonal group O1:K1 STc95 of NMEC strains is mainly composed of a cluster with many virulence factors but of only moderate virulence. Whether its emergence is due to its ability to colonize the gut thanks to FimH30 or pS88-like plasmid remains to be determined
Rapid and Simple Universal Escherichia coli Genotyping Method Based on Multiple-Locus Variable-Number Tandem-Repeat Analysis Using Single-Tube Multiplex PCR and Standard Gel Electrophoresis
International audienceWe developed a multiplex PCR method based on multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) that was designed for the rapid typing of Escherichia coli and Shigella isolates. The method amplifies seven VNTRs and does not require a sequencing capillary or fluorescent dyes. The amplification products are simply loaded on a standard agarose gel for electrophoresis, and the banding patterns are analyzed visually. We evaluated the method on 220 strains belonging to different collections: the E. coli reference (ECOR) collection (nâ=â72), O1:K1 isolates causing neonatal meningitis (nâ=â38), extended-spectrum beta-lactamase-producing fecal isolates belonging to the worldwide sequence type 131 (ST131) clone (nâ=â38), Shiga toxin-producing E. coli (STEC) isolates of serogroups O157:H7 (nâ=â21) and O26 (nâ=â16, 8 of which belonged to an outbreak), 27 Shigella isolates (22 Shigella sonnei isolates, including 5 epidemic strains), and 8 reference strains. The performances were compared to those of multilocus sequence typing (MLST), the DiversiLab automated repetitive element palindromic PCR (REP-PCR), pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing (WGS). We found 66 different profiles among the isolates in the ECOR collection. Among the clonal group O1:K1 isolates, 14 different profiles were identified. For the 37 STEC isolates, we found 23 profiles, with 1 corresponding to the 8 epidemic strains. We found 19 profiles among the 27 Shigella isolates, with 1 corresponding to the epidemic strain. The method was able to recognize strains of the ST131 clone and to distinguish the O16 and O25b serogroups and identified 15 different MLVA types among them. This method allows the simple, fast, and inexpensive typing of E. coli/Shigella isolates that can be carried out in any laboratory equipped for molecular biology and has a discriminatory power superior to that of MLST and DiversiLab REP-PCR but slightly lower than that of PFGE.IMPORTANCE Fast typing methods that can easily and accurately distinguish clonal groups and unrelated isolates are of particular interest for microbiologists confronted with outbreaks or performing epidemiological studies. Highly discriminatory universal methods, like PFGE, optical mapping, or WGS, are expensive and/or time-consuming. MLST is useful for phylogeny but is less discriminatory and requires sequencing facilities. PCR methods, which are fast and easy to perform, also have drawbacks. Random PCRs and REP-PCR are universal but lack reproducibility. Other PCR methods may lack the discriminatory power to differentiate isolates during outbreaks. MLVA combines the advantages of PCR methods with a high discriminatory power but in its standard form requires sequencing capillary electrophoresis. The method that we have developed combines the advantages of standard PCR (simple, fast, and inexpensive) with the high discriminatory power of MLVA and permits the typing of all E. coli isolates (either intestinal or extraintestinal pathogenic isolates as well as commensal isolates)
Emerging multidrug-resistant hybrid pathotype shiga toxin-producing escherichia coil O80 and related strains of clonal complex 165, Europe
Enterohemorrhagic Escherichia coli serogroup O80, involved
in hemolytic uremic syndrome associated with extraintestinal
infections, has emerged in France. We obtained circularized
sequences of the O80 strain RDEx444, responsible for hemolytic uremic syndrome with bacteremia, and noncircularized
sequences of 35 O80 E. coli isolated from humans and animals in Europe with or without Shiga toxin genes. RDEx444
harbored a mosaic plasmid, pR444_A, combining extraintestinal virulence determinants and a multidrug resistanceâ
encoding island. All strains belonged to clonal complex 165,
which is distantly related to other major enterohemorrhagic E.
coli lineages. All stx-positive strains contained eae-Ο, ehxA,
and genes characteristic of pR444_A. Among stx-negative
strains, 1 produced extended-spectrum ÎČ-lactamase, 1 harbored the colistin-resistance gene mcr1, and 2 possessed
genes characteristic of enteropathogenic and pyelonephritis
E. coli. Because O80âclonal complex 165 strains can integrate intestinal and extraintestinal virulence factors in combination with diverse drug-resistance genes, they constitute
dangerous and versatile multidrug-resistant pathogensWe thank Roger Stephan and Lothar Beutin for providing the
strains from Switzerland and Germany, respectively.
This work was financed by Fonds dâEtudes et de Recherche du
Corps MĂ©dical, AP-HP. Work in the Laboratorio de Referencia
de Escherichia coli was financed by grant no. ED431C-2017-57
from ConsellerĂa de Cultura, EducaciĂłn e OrdenaciĂłn
Universitaria (Xunta de Galicia) and the European Regional
Development FundS
Cultiver les lettres médiévales aujourd'hui
Ă un moment oĂč la transmission des savoirs et la formation des enseignants sont en pleine redĂ©finition, oĂč les humanitĂ©s connaissent une crise de lĂ©gitimitĂ©, le numĂ©ro 36 de Perspectives mĂ©diĂ©vales interroge la place des lettres mĂ©diĂ©vales dans lâenseignement, la sociĂ©tĂ© et la citĂ©. Quelle pertinence y a-t-il Ă cultiver les lettres mĂ©diĂ©vales aujourdâhui ? Quels enjeux y a-t-il Ă les soigner, les faire croĂźtre et embellir ? Quels fruits le monde contemporain peut-il rĂ©colter de la culture des lettres mĂ©diĂ©vales ? Les contributions de ce numĂ©ro rĂ©flĂ©chissent aux voies de transmission et de mĂ©diation de la langue et de la littĂ©rature du Moyen Ăge, Ă travers plusieurs axes. Lâenseignement dâabord, primaire, secondaire et universitaire, en France et Ă lâĂ©tranger : quelle place est donnĂ©e, quelle place faut-il donner Ă la littĂ©rature mĂ©diĂ©vale, et comment inventer ou rĂ©inventer dĂ©marches pĂ©dagogiques et didactiques ? Comment transmettre aux Ă©lĂšves et aux Ă©tudiants le goĂ»t du Moyen Ăge, comment sâappuyer sur le pouvoir de dĂ©paysement de cette pĂ©riode tout en en Ă©clairant la pertinence pour le monde contemporain ? Les productions et pratiques culturelles ensuite : la littĂ©rature mĂ©diĂ©vale est connue du « grand public » par le biais dâĂ©critures ou de rĂ©Ă©critures qui convoquent, rappellent, hybrident les langues et les textes. Ses supports matĂ©riels, manuscrits et images, prennent place Ă la fois dans des expositions musĂ©ales et savantes, et dans lâimagerie vĂ©hiculĂ©e par diffĂ©rents mĂ©dias. Le numĂ©ro accorde une large place Ă des tĂ©moignages et des entretiens portant sur des modes divers dâincarnation des textes du Moyen Ăge : adaptations, crĂ©ations ou recrĂ©ations musicales et thĂ©Ăątrales, visant Ă incarner et Ă revivifier les lettres mĂ©diĂ©vales. SĂ©bastien Douchet avec la collaboration de Sophie Albert et de Patricia Victori