Objectives: The objective was to study a new vanG-type locus in Clostridium argentinense vanG Car 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 vanG Car 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.

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... sults: The vanG Car 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 vanG Car was not expressed without or with induction by a subinhibitory concentration of vancomycin. Conclusions: The new vanG Car locus was cryptic in C. argentinense and intrinsic to this species. Emergence of vancomycin resistance in C. argentinense due to decryptification of the vanG Car gene cluster could occur.