Whole-Genome Analysis of an Extensively Drug-Resistance Empedobacter falsenii Strain Reveals Distinct Features and the Presence of a Novel Metallo-β-Lactamase (EBR-2)

The spread of antibiotic resistance is rapidly threatening the effectiveness of antibiotics in the clinical setting. Many infections are being caused by known and unknown pathogenic bacteria that are resistant to many or all antibiotics currently available. Empedobacter falsenii is a nosocomial pathogen that can cause human infections. E. falsenii Wf282 strain was found to be resistant to many antibiotics, including carbapenems and colistin. Whole-genome shotgun sequencing of the strain was performed, and distinct features were identified. A novel metallo-beta-lactamase, named EBR-2, was found, suggesting a potential role of E. falsenii as a reservoir of beta-lactamases and other resistance determinants also found in its genome. The EBR-2 protein showed the highest catalytic efficiency for penicillin G as compared to meropenem and ampicillin and was unable to hydrolyze cefepime. The results described in this work broaden the current understanding of the role of beta-lactamases in the Flavobacteriaceae family and suggest that E. falsenii Wf282 may be a reservoir of these novel resistance determinants.