Characterization and Genomic Analysis of a New Bacteriophage Klebsiella pneumoniae CTF-1 from Turkey

Background Klebsiella pneumoniae is a clinically important pathogen causing respiratory tract infections, pneumonia, wound infections, urinary tract infections and sepsis. It is on the priority pathogen list of the World Health Organization (WHO) due to the resistant infections it causes. The K. pneumoniae CTF1 phage is a novel lytic phage with the highest overall similarity of 82.19% against K. pneumoniae isolated from clinical wound infections. In this study, the whole genome analysis of The K. pneumoniae CTF1 phage was conducted. Results The K. pneumoniae CTF1 phage has a linear double-stranded DNA genome 40,841 bp long with 53.1% GC content. Totally 44 protein coding genes were identified in phage genome. 31 of which were assigned functions as genome replication, phage packaging, structural proteins or phage lysis. K. pneumoniae CTF-1 is a member of the Przondovirus genus within the Caudovirales order. The objective of the research was to explore the effectiveness of lytic K. pneumoniae CTF-I bacteriophage isolate on panresistant K. pneumoniae isolates. The K. pneumoniae CTF1 phage was effective against 22 (88%) of 25 K. pneumoniae strains. The optimum efficacy of phage K. pneumoniae CTF-1 was 37–45°C, and the optimal effectiveness of the phage was pH between 4–9. The latent time and lytic cycle of the phage were around 40 min and burst size was around 92 PFU/mL. Conclusions The K. pneumoniae CTF-1 phage is an excellent candidate for phage therapy due to its high lytic activity against panresistant Klebsiella and lack of antibiotic resistance genes, toxins, virulence factors or integrase genes.