Isolation and characterization of novel bacteriophage vB_KpP_HS106 for Klebsiella pneumonia K2 and applications in foods

The detection rate of Klebsiella pneumoniae in food is increasing, and it has emerged as a food pathogen. Global health is threatened due to the emergence of multidrug-resistant (MDR) and hypervirulent (hv) K. pneumoniae. Phages have a promising application as antibacterial agents and have the ability to lyse MDR strains. Hence, phage vB_KpP_HS106 against MDR-hv K. pneumoniae strains was isolated from sewage collected from a hospital. It can maintain stable activity at a pH range of 4–12 and a temperature range of 4°C to 50°C. The maximum adsorption rate of phage HS106 was found to be approximately 84.2% at 6 min. One-step growth curve analysis showed that the latent period of HS106 was 10 min and the burst size was approximately 183 PFU/cell. Furthermore, whole genome analysis indicated that the genome of phage HS106 was a double-stranded linear 76,430-bp long DNA molecule with 44% GC content. A total of 95 open reading frames were annotated in the HS106 genome, which did not contain any virulence genes or antibiotic resistance genes. Phage HS106 reduced MDR K. pneumoniae in milk by approximately 1.6 log(10) CFU/mL at 25°C and in chicken by approximately 2 log(10) CFU/cm(3) at 25°C. Therefore, vB_KpP_HS106 is a promising alternative to antibiotics for biocontrol against multidrug-resistant K. pneumoniae in foods.