Genomic characterization of a local epidemic reveals specific features of the widespread clone ST395.
Fiche publication
Date publication
octobre 2017
Journal
Microbial genomics
Auteurs
Membres identifiés du Cancéropôle Est :
Pr HOCQUET Didier
Tous les auteurs :
Petitjean M, Martak D, Silvant A, Bertrand X, Valot B, Hocquet D
Lien Pubmed
Résumé
is a ubiquitous opportunistic pathogen with several clones being frequently associated with outbreaks in hospital settings. ST395 is among these so-called 'international' clones. We aimed here to define the biological features that could have helped the implantation and spread of the clone ST395 in hospital settings. The complete genome of a multidrug resistant index isolate (DHS01) of a large hospital outbreak was analysed. We identified DHS01-specific genetic elements, among which were identified those shared with a panel of six independent ST395 isolates responsible for outbreaks in other hospitals. DHS01 has the fifth largest chromosome of the species (7.1 Mbp), with most of its 1555 accessory genes borne by either genomic islands (GIs, =48) or integrative and conjugative elements (ICEs, =5). DHS01 is multidrug resistant mostly due to chromosomal mutations. It displayed signatures of adaptation to chronic infection in part due to the loss of a 131 kbp chromosomal fragment. Four GIs were specific to the clone ST395 and contained genes involved in metabolism (GI-4), in virulence (GI-6) and in resistance to copper (GI-7). GI-7 harboured an array of six copper transporters and was shared with non-pathogenic sp. retrieved from copper-contaminated environments. Copper resistance was confirmed phenotypically in all other ST395 isolates and possibly accounted for the spreading capability of the clone in hospital outbreaks, where water networks have been incriminated. This suggests that genes transferred from copper-polluted environments may have favoured the implantation and spread of the international clone ST395 in hospital settings.
Mots clés
Pseudomonas aeruginosa, copper, high-risk clone, multidrug resistance, outbreak
Référence
Microb Genom. 2017 10;3(10):e000129