In vitro study demonstrates potent lytic activity and biofilm reduction against Enterococcus faecium by novel phage vB_EfaP_2/Chl-5, indicating its potential for phage therapy.
Key Points
To isolate and characterize the biological features, genomic profile, and therapeutic properties of a novel lytic bacteriophage targeting pathogenic Enterococcus faecium.
Isolated bacteriophage vB_EfaP_2/Chl-5 from a human bronchoalveolar lavage sample and examined viral morphology via electron microscopy.
Performed full-genome sequencing, single-step growth assays, adsorption kinetics, and stability profiling across varied temperatures (-70 to 60°C), pH levels (4.0 to 10.0), and salinity (5% NaCl).
Assessed lytic host range across clinical E. faecium isolates (n = 14) and quantified in vitro anti-biofilm activity.
The phage belongs to the Salasmaviridae family (podovirus morphotype) with an 18,099 bp double-stranded DNA genome encoding 27 open reading frames devoid of antibiotic resistance, virulence, or lysogeny genes.
Exhibited rapid adsorption (70% within 5 min), a 40-minute latent period, a burst size of 68 plaque-forming units per cell, and high infection productivity (efficiency of plating ≥0.5) in 26% of tested E. faecium isolates (n = 14).
Maintained infectivity across broad thermal and pH ranges, in 5% NaCl, and significantly reduced viable cell counts within established bacterial biofilms.