Isolation and Characterization of Two Lytic Pseudomonas aeruginosa Phages

In recent years, utilizing bacteriophages to combat multidrug-resistant bacteria such as Pseudomonas aeruginosa has gained significant global attention. This research describes the isolation and detailed characterization of two lytic Pseudomonas phages, Isf1 and Isf2 , recovered from wastewater samples. Transmission electron microscopy analysis showed Isf1 belongs to the Siphoviridae family, whereas Isf2 represents a Podoviridae member. Both phages displayed efficient adsorption kinetics, achieving roughly 50% adsorption within 8–10 min, and burst sizes of ∼100 PFU and 70 PFU per infected cell, respectively. Isf1 maintained viability across 4–50°C and Isf2 across 4–40°C and pH conditions (6.0–9.0). Genomic sequencing revealed dsDNA genomes measuring 94,579 bp (55.19% GC) and 44,746 bp (52.50% GC) for Isf1 and Isf2 , respectively. Comparative studies demonstrated separate evolutionary pathways and different taxonomic classifications. BLASTn analysis indicated Isf1 possesses 98.45% identity with Pseudomonas phage SM1, whereas Isf2 displays 96.44% identity with phage DL54. No virulence or antimicrobial resistance genes were identified, indicating their suitability for therapeutic purposes.