Isolation Identification and Evaluation of Two Lytic Bacteriophages Against Clinical Antibiotic-Resistant Strains of Pseudomonas aeruginosa from Waste Water and Hospital Sewage of Isfahan City

Phagetherapy is the therapeutic use of bacteriophages to treat pathogenic bacterial infections as alternative to antibiotics for treatment of resistant bacteria. The aims of this study were to isolate, identify and evaluate effective bacteriophages active against antibiotic resistant strains of Pseudomonas aeruginosa.
Different Pseudomonas aeruginosa strains isolated from clinical specimens during 9 months (July 2013 to March 2014) in three Isfahan hospitals (AlZahra, Omid and Shahid Beheshti hospitals) and Kirby Bauer's disc diffusion method was used for determination of resistance profiles of these isolates using different antibiotics including Amikacin, Imipenem, Meropenem, Ciprofloxacin, Ceftazidime, Cefepime, Cefotaxime, Piperacillin-tazobactam. The resistant strains to all tested antibiotics were selected for finding their specific bacteriophages from waste water and
hospital sewage. Presence of phage investigated by plaque formation and after enrichment and stained of samples, TEM microscope was used for determination of phage morphology and size.
Findings: Among 81 Pseudomonas aeruginosa isolates, 38 isolates (47%) were resistant to all tested antibiotics and plaque due to phages was detected against 32 (84%) among these 38 isolates. Two phages belong to Cystoviridae and Leviviridae identified using TEM microscope.
Discussion & It seems that the mixture of two phages (cocktails phages) that has high bactericidal effect against resistant strains of Pseudomonas aeruginosa can be good candidates for use in phagetherapy.