THE TROJAN HORSE: SERRATIA MARCESCENS”. IMPORTANCE IN THE DISSEMINATION, UPTAKE AND MAINTENANCE OF GENES ASSOCIATED WITH ANTIMICROBIAL RESISTANCE IN THE HOSPITAL ENVIRONMENT

ANAHÍ SAMANTA GAMBINO; CAROLINA LEGUINA; CAMILA KNECHT; FERNANDO MARTÍN ALONSO; MARIANA MASSÓ; OLINCA AYALA NUÑEZ; GABRIELA CAMICIA; CLAUDIA VARGAS; LAURA CARRERA PÁEZ; MARÍA PAULA QUIROGA; DANIELA CENTRÓN

Congreso; International Union of Microbiological Societies 2022 (IUMS 2022); 2022

Union of Microbiological Societies

Abstract 290"THE TROJAN HORSE: SERRATIA MARCESCENS”. IMPORTANCE IN THE DISSEMINATION, UPTAKE ANDMAINTENANCE OF GENES ASSOCIATED WITH ANTIMICROBIAL RESISTANCE IN THE HOSPITAL ENVIRONMENTBackground and AimsAntimicrobial resistance (AMR) is a global public health problem. Carbapenemase New-Delhi (NDM-1) causestherapeutic failures with currently available antibiotics. In addition, Serratia marcescens is naturally resistant toseveral antibiotics, including colistin. Our aim was to analyze the genetic platforms involved in thedissemination of bla NDM-1 in a S. marcescens multidrug-resistant (MDR) strain. MethodsS. marcescens SM938 was isolated in 2018 and sequenced by Miseq. The contigs were assembled with SPAdes3.9.0. The genome was annotated with Prodigal, RefSeq database and Blast. Insertion sequences were searchedby ISfinder. Antimicrobial resistance genes (ARG) were identified using RESfinder, CARD and Blastn. Theresistance phenotype was assessed by disk diffusion and MIC. Plasmid conjugation and maintenance assayswere performed with both E. coli J53 and S. marcescens SCH909 as recipient strains. ResultsGenetic platforms related to the dissemination of ARG were found including the IncC-type pDCASG6-NDMplasmid (137.269 pb, G+C: 52%), which contains a genomic resistance island (17.833 pb) with bla NDM-1 .Maintenance studies showed that only in the transconjugants obtained with S. marcescens SCH909, pDCASG6-NDM was maintained over ten days without antimicrobial pressure. The transconjugants obtained with E. coliJ53, showed that the 80% of pDCASG6-NDM was lost at the day 10. ConclusionsThese findings, and the fact that S. marcescens is considered a relevant nosocomial pathogen that can have awide range of niches –human, plant, animal, soil, and inanimate surfaces, showed the ability of this species tocapture, maintain and spread a broad variety of AMR platforms and ARG, including bla NDM-1 .