title: Microbiological changes and diversity in autochthonous non-toxigenic Corynebacterium diphtheriae isolated in France.
abstract: Autochtonous toxigenic Corynebacterium diphtheriae have disappeared in mainland France, but non-toxigenic C. diphtheriae are still circulating. Using phenotypic and molecular tools, we retrospectively characterized 103 non-toxigenic C. diphtheriae collected in mainland France and highlight several changes. The proportion of C. diphtheriae belfanti increased between 1977 and 2011 and it is the most frequent biotype recovered in recent years. Resistance to ciprofloxacin has increased and most isolates with decreased sensitivity belong to the belfanti biotype. Using multilocus sequence typing, we demonstrate that French isolates are distributed in a large number of sequence types and identify three distinct lineages. C. diphtheriae mitis and gravis form lineage I while C. diphtheriae belfanti forms lineages II and III. Almost all isolates of lineage II are part of a unique clonal complex or are very close to it. Most French isolates have a dtxR sequence homologous to that of toxigenic isolates, suggesting that if lyzogenised by a corynephage, they can express diphtheria toxin.
authors: Institut Pasteur, Unité Prévention et Thérapies Moléculaires des Maladies Humaines, Centre National de Référence des Corynébactéries du Complexe Diphtheriae, Paris, France; CNRS-URA 3012, Paris, France.
authors: E
authors: E
authors: Farfour
authors: E
authors: E
authors: Badell
authors: S
authors: S
authors: Dinu
authors: S
authors: S
authors: Guillot
authors: N
authors: N
authors: Guiso
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D003353:Corynebacterium diphtheriae / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D004165:Diphtheria / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology; D005602:France; D006801:Humans; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C075586:DtxR protein, Corynebacterium diphtheriae; D024841:Fluoroquinolones
keywords: Antibiotic resistance; Corynebacterium diphtheriae; belfanti; diphtheria; fluoroquinolone; non-toxigenic; toxoid