In Vitro Activity, Stability and Molecular Characterization of Eight Potent Bacteriophages Infecting
Abeer Ameen Baqer1,2, Kokxin Fang2, Norfarhan Mohd-Assaad3,4
1Medical Laboratory Techniques Department, Dijlah University College, Baghdad 10021, Iraq.
Background:
Members of the genus Klebsiella are among the leading microbial pathogens associated with nosocomial infection. The increased incidence of antimicrobial resistance in these species has propelled the need for alternate/combination therapeutic regimens to aid clinical treatment, including bacteriophage therapy. Bacteriophages are considered very safe and effective in treating bacterial infections. In this study, we characterize eight lytic bacteriophages that were previously isolated by our team against carbapenem-resistant Klebsiella pneumoniae.
Methods:
The one-step-growth curves, stability and lytic ability of eight bacteriophages were characterized. Restriction fragment length polymorphism (RFLP), random amplification of polymorphic DNA (RAPD) typing analysis and protein profiling were used to characterize the microbes at the molecular level. Phylogenetic trees of four important proteins were constructed for the two selected bacteriophages.
Results And Conclusions:
All eight bacteriophages showed high efficiency for reducing bacterial concentration with high stability under different physical and chemical conditions. We found four major protein bands out of at least ten 15-190 KDa bands that were clearly separated by SDS-PAGE, which were assumed to be the major head and tail proteins. The genomes were found to be dsDNA, with sizes of approximately 36-87 Kb. All bacteriophages reduced the optical density of the planktonic K. pneumoniae abruptly, indicating great potential to reduce K. pneumoniae infection. In this study, we have found that tail fiber protein can further distinguished closely related bacteriophages. The characterised bacteriophages showed promising potential as candidates against carbapenem-resistant Klebsiella pneumoniae via bacteriophage therapy.
Insights
Eight bacteriophages were characterized for their effectiveness against carbapenem-resistant Klebsiella pneumoniae. These lytic bacteriophages demonstrated high stability and lytic efficiency, showing great potential for phage therapy against resistant bacterial infections.
Area of Science:
- Microbiology
- Virology
- Infectious Diseases
Background:
- Klebsiella species are leading causes of hospital-acquired infections.
- Rising antimicrobial resistance necessitates alternative treatments like bacteriophage therapy.
- Bacteriophages offer a safe and effective therapeutic approach for bacterial infections.
Purpose of the Study:
- To characterize eight lytic bacteriophages against carbapenem-resistant Klebsiella pneumoniae.
- To evaluate the stability, lytic ability, and molecular profiles of these bacteriophages.
- To assess their potential as therapeutic agents.
Main Methods:
- One-step-growth curves, stability assays, and lytic activity assessments.
- Molecular characterization using Restriction Fragment Length Polymorphism (RFLP) and Random Amplification of Polymorphic DNA (RAPD) typing.
- Protein profiling via SDS-PAGE and phylogenetic analysis of key proteins.
Main Results:
- All eight bacteriophages exhibited high bacterial reduction efficiency and stability under various conditions.
- SDS-PAGE revealed four major protein bands (15-190 KDa), likely head and tail proteins.
- Genomes were double-stranded DNA (dsDNA) ranging from 36-87 Kb.
- Bacteriophages rapidly reduced optical density of planktonic K. pneumoniae.
Conclusions:
- Tail fiber protein analysis effectively distinguished closely related bacteriophages.
- The characterized bacteriophages show significant promise for phage therapy against carbapenem-resistant K. pneumoniae.
- These findings support bacteriophage therapy as a viable strategy against multidrug-resistant bacteria.
