Genetic insights into Shewanella spp., progenitor of the bla OXA-48-like genes: a large-scale study

Résumé fourni par la source

Shewanella spp. played pivotal ecological roles and were reported to be the progenitor of bla OXA-48-like carbapenemase genes. However, it remained unknown which species was the progenitor of different OXA-48 carbapenemase variants. To address this issue, we analysed the largest collection of Shewanella genomes to our knowledge and performed genetic and phenotypic analysis on Shewanella collected from Zhejiang province, China. Our results suggested that bla OXA-48-like was intrinsically carried by a few Shewanella species and different bla OXA-48-like variants were associated with different Shewanella species; for instance, Shewanella baltica was associated with bla OXA-924, and some Shewanella oncorhynchi and Shewanella putrefaciens carried bla OXA-900-like. The bla OXA-48-like genes carried by Shewanella xiamenensis were highly diverse. Comparatively, none of the Shewanella algae genomes carried bla OXA-48-like. Results of phylogenetic analysis supported the notion that OXA-48-like carbapenemase originated from different environmental Shewanella species and was captured by clinical species, particularly Enterobacterales. Different Shewanella species distributed in different niches in Zhejiang province, i.e. S. algae (n=12) and Shewanella indica (n=1) strains were all isolated from clinical settings and S. xiamenensis (n=23) and Shewanella mangrovisoli (n=2) were isolated from both hospital sewage and river water. bla OXA-48-like genes in Shewanella spp. from Zhejiang province were located on the chromosome. To the best of our knowledge, this is the first study investigating the progenitor of different bla OXA-48-like variants with a focus on the Shewanella population. Results in this study highlighted the important role of Shewanella species in the ecosystem, particularly as the major source of the notorious carbapenemase gene, bla OXA-48. Control measures should be implemented to prevent further dissemination of such organisms in the hospital setting and the community.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.