Isolation and characterization of lytic bacteriophages with therapeutic potential against multidrug resistant Klebsiella pneumoniae from Ethiopia

Klebsiella pneumoniae is a common pathogen responsible for various infections, with multidrug-resistant (MDR) strains increasingly complicating treatment. Phage therapy has shown significant potential in treating difficult bacterial infections; however, research specifically focused on phages targeting this bacterium remains limited. This study aimed to isolate and characterize lytic bacteriophages that target multidrug-resistant K. pneumoniae. Phages were isolated from 66 environmental samples through spot assays conducted on 10 multidrug-resistant strains. Phages were isolated via spot assays and purified via streak plating. Characterization included PCR-based identification and classification, determination of the latent period, efficiency of plating, burst size, stability testing, and evaluation of in vitro bactericidal activity. From a total of 660 spots tested against 10 multidrug-resistant (MDR) isolates, 102 phages were successfully isolated. These phages demonstrated individual lytic activity ranging from 8% (4/46) to 63% (29/46). PCR-based classification of the 60 bacteriophages identified six distinct virulent phage genera, with Taipeivirus being the most prevalent at 18.3% (11/60) and Webervirus the least common at 10.0% (6 out of 60). Stability assessments of pH and temperature demonstrated optimal activity between pH 5 and 9 and at temperatures up to 50 °C. These results endorse phage therapy as a viable alternative for treating MDR and hypervirulent K. pneumoniae infections. The data offer critical insights into local bacteriophage diversity and underscore its potential for developing targeted therapeutic agents. Genome sequencing, in vivo studies, and clinical trials are required to validate the efficacy and safety of these phages.