Molecular Characterization and Host Range Analysis of Lytic Bacteriophages Targeting Multidrug-Resistant Pseudomonas aeruginosa from Wastewater in Peru

Abstract

Multidrug-resistant Pseudomonas aeruginosa (MDR-PA) represents a major global public health problem, limiting therapeutic options and increasing morbidity and mortality. This study reports the isolation, molecular characterization, and stability assessment of lytic bacteriophages active against MDR-PA strains recovered from urban wastewater in Trujillo, Peru. Sixteen clinical MDR-PA isolates were confirmed through phenotypic and biochemical tests, and their resistance to 13 antibiotics was evaluated. Eight lytic bacteriophages were obtained and assessed for viability under different storage temperatures (4°C, −30°C, −80°C), elevated temperatures (37–47°C), pH conditions (3, 7, 9), UV radiation exposure (5–60 s), and host range against all bacterial isolates. Molecular characterization was performed by restriction fragment length polymorphism (RFLP) analysis using EcoRI, BamHI, and HindIII enzymes. Phages F1AO-510 and F1AO-506 exhibited the broadest host ranges, lysing 56.25% and 43.75% of MDR-PA strains, respectively. Most phages retained infectivity for three months at 4°C and remained stable at −80°C, whereas UV exposures longer than 30 seconds markedly reduced viability. RFLP profiles revealed distinct genomic patterns, highlighting their genetic diversity and potential for inclusion in targeted phage cocktails. These findings underscore the therapeutic value of lytic bacteriophages as alternative antimicrobial agents and their applicability in phage-based interventions in regions with a high prevalence of antimicrobial resistance.