A vanG-type locus in Clostridium argentinense

Nicolas Berthet (1) , Bruno Périchon (2) , Christelle Mazuet (3) , Diana Chapetón-Montes (3) , Christiane Bouchier (4) , Philippe Bouvet (3) , Christine Legeay (3) , Michel Popoff (3) , Patrice Courvalin (2)

1 CIRMF - Centre International de Recherches Médicales de Franceville
2 Agents antibactériens
3 Bactéries anaérobies et Toxines
4 Génomique (Plate-Forme) - Genomics Platform

OBJECTIVES: The objective was to study a new vanG-type locus in Clostridium argentinense vanGCar and to determine its impact on glycopeptide susceptibility of the host. METHODS: The whole genome of C. argentinense NCIB 10714 was sequenced using Illumina single-reads sequencing technology. The presence of vanGCar in seven C. argentinense strains was tested by PCR and its expression was tested by quantitative RT–PCR (qRT–PCR). Glycopeptide susceptibility was determined by the Etest procedure. RESULTS The vanGCar locus contained four genes encoding a carboxypeptidase, a d-alanine:d-serine ligase, a serine transporter and a serine racemase, and was present in the seven C. argentinense studied. An AraC-type transcriptional regulator was found upstream from the genes. C. argentinense NCIB 10714 was susceptible to vancomycin and to teicoplanin. qRT–PCR experiments revealed that vanGCar was not expressed without or with induction by a subinhibitory concentration of vancomycin. CONCLUSION The new vanGCar locus was cryptic in C. argentinense and intrinsic to this species. Emergence of vancomycin resistance in C. argentinense due to decryptification of the vanGCar gene cluster could occur.

Keywords: C. argentinense; resistance; vancomycin

Domains: Life Sciences [q-bio]; Microbiology and Parasitology; Bacteriology

Nicolas Berthet, Bruno Périchon, Christelle Mazuet, Diana Chapetón-Montes, Christiane Bouchier, et al.. A vanG-type locus in Clostridium argentinense. Journal of Antimicrobial Chemotherapy, 2015, 70 (7), pp.1942 - 1945. ⟨10.1093/jac/dkv073⟩. ⟨pasteur-01675650⟩