| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1431-1 | ||||
Resumo:In the present study we demonstrate an in-depth characterization of two blaKPC-2 encoding plasmids found in the Enterobacter kobei FL23 strain recovered from recreational coastal waters in Rio de Janeiro, Brazil. The plasmids here characterized belong to distinct incompatibility groups and carry a diverse collection of resistance genes to multiple antimicrobial classes. The focus of our study was the blaKPC-2 gene, one of the most important resistance determinants in gram-negative bacteria due to its carbapenemase product. Interestingly, the genetic context of the blaKPC-2 gene was dissimilar in each of them. While pEkFL23-IncX3 presents a new Tn4401k, a new isoform, similar to Tn4401b but with a truncated Tn3 transposase; pEkFL23-IncU/P6 carries a new isoform of a non-Tn4401 element (NTEKPC), named NTEKPC-IIh. Its difference from NTEKPC-IId is the truncated Tn3 resolvase upstream of blaKPC-2. Going beyond genomic analysis, the capacity of conjugation, maintenance rates and fitness cost of both replicons were also assessed. Both were transferred after mating assays, whereas only pEkFL23-IncX3 was transferred under the adverse conditions of Marine broth at 25°C as a mating platform. Maintenance rates were assessed by replica plating technique which showed remarkable stability of both plasmids in the parental and transconjugant strains. Lastly, neither of the replicons presented significant fitness cost to their transformant hosts, with pEkFL23-IncU/P6 conferring a statistically significant (p < 0.05) advantage in head-to-head competitions. Our findings show that E. kobei FL23 is a disquieting case of a carbapenem resistant bacteria identified in a community setting, being a possible silent disseminator of two seemingly stable and metabolic weightless multidrug resistance plasmids. Palavras-chave: Carbapenem resistance, Plasmid fitness, Plasmid maintenance, KPC-2, Coastal Waters Agência de fomento:CNPq, FAPERJ, INPRA, CAPES | |||||