Multidrug resistance in foodborne pathogens poses a critical threat to food safety and public health. Enterobacter hormaechei is an emerging pathogen with wide environmental prevalence and is capable of causing severe infections. Bacteriophage-based intervention has gained significant recognition as a sustainable approach to combat foodborne pathogens and address antimicrobial resistance in food production systems. Despite this, research on E. hormaechei -specific phages is facing substantial challenges, primarily due to insufficient phage collections and inadequate genomic characterization of existing isolates. In this work, two novel virulent phages (Ehp-YZU-L3 and Ehp-YZU-L4) were isolated from wastewater samples in Yangzhou. Their morphological, biological, and genomic features were characterized. The two phages belonged to the Myoviridae family, with a latency period (10 and 40 min) and high burst size (192 and 292 plaque-forming unit PFU/host cell), and an optimal multiplicity of infection of 0.01. The complete genomic sequences of phages ranged from 163,779 to 170,652 bp and GC content of 39.8 − 40.2%, which consisted of 296 and 275 open reading frames of phage Ehp-YZU-L3 and Ehp-YZU-L4. The absence of both virulence-related genetic elements, antimicrobial resistance, and lysogeny-related genes in two genomes was confirmed. Two phages exhibited strong inhibitory effects against E. hormaechei in pork by a phage-dosage–dependent way, with a reduction range of bacterial counts by 1.73–2.87 Log CFU/g for Ehp-YZU-L3 and 1.96–3.20 log CFU/g for Ehp-YZU-L4 at 37°C for 4 h. These findings demonstrate considerable potential of these two phages for the biocontrol of E. hormaechei contamination in food production systems.
Liu et al. (Thu,) studied this question.