Isolation and characterization of a lytic bacteriophage against Klebsiella pneumoniae and evaluation of its antibacterial effect on clinical isolates of Pseudomonas aeruginosa and Staphylococcus aureus

BACKGROUND AND OBJECTIVESDue to the emergence of antibiotic-resistant strains of bacteria such as Klebsiella pneumoniae, the use of antibacterial potential of bacteriophages has been considered as an effective approach in controlling the infections.MATERIALS AND METHODSAfter isolating lytic bacteriophage (PKpMa۱/۱۹) against K.pneumoniae PTCC۱۲۹۰ by agar bilayer method, purification, titration and enrichment of the bacteriophage were performed. Morphological characteristics of PKpMa۱/۱۹ were determined using electron microscopy. One step growth, latent period, burst size and lytic activity of the phage in different environmental conditions (temperature, pH, UV and Chloroform) were determined. In the next step, host range of the bacteriophage was evaluated against different clinical isolates from clinical infections using spot test.RESULTS AND DISCUSSIONBacteriophage belonging to Tectiviridae family was isolated and purified. Its latent period and burst size were ۲۰-۲۵ min and ۳۱۱ PFU, respectively. Appropriate lytic effect of the bacteriophage was shown between -۲۲ and ۳۷ ℃. Stability of the phage was high in pH= ۴-۱۰. Chloroform had no effect on viability of the phage. The phage (PKpMa۱/۱۹), was effective against one of the ۲۰ clinical isolates of K.pneumoniae, but it showed antibacterial effect on ۱۰ Pseudomonas aeroginosa and ۱۶ Staphylococcus aureus isolates.CONCLUSIONPhage therapy could be a natural biologic approach against clinical isolates of bacteria in nosocomial infections, but evaluation of antibacterial effects of candidate phage(s) against causative bacterial isolates and determining their characteristics is essential for therapeutic application.

کلیدواژه ها:

Antibiotic Resistance ، Bacteriophage ، Klebsiella Pneumonia ، Phage Therapy