First Report in the Americas of Var. Enteritidis Carrying in a Putatively New Sub-Lineage of IncC2 Plasmids.

BACKGROUND

Infections caused by carbapenem-resistant Enterobacterales have steadily multiplied over time, becoming a major threat to healthcare systems due to limited therapeutic options and high case-fatality rates.

CASE REPORT

We studied a patient who, after being discharged from an ICU, developed salmonellosis caused by an antibiotic-susceptible . After undergoing treatment with ciprofloxacin, the patient presented an episode of asymptomatic bacteriuria originated by a carbapenem and ciprofloxacin-resistant .

RESULTS

Whole genome sequencing analysis revealed that both isolates belonged to the same strain, and that isolate SEn_T2 acquired a plasmid carrying both and genes (pIncCSEn) which was previously present in the patient's gut in at least one isolate. Additionally, pIncCSEN was identified as a putatively new sub-lineage of IncC2 plasmids which lacked the first copy of the methyltransferase gene and the gene. The resistance genes and were incorporated into a Tn-derived transposon that included a complex class 1 integron whose genetic arrangement was: - - - - --IS- - - (in reverse direction)- IS-IS- - - -.

CONCLUSIONS

Antimicrobial persistence and co-selection of antibiotic resistance play an important role in the dissemination of antimicrobial resistance genes; in this regard, a joint effort involving the infection control team, effective antibiotic stewardship, and genomic surveillance could help mitigate the spread of these multidrug resistant microorganisms.