Isolation and characterization of bacteriophages from sewerage water targeting methicillin resistance S. aureus in burn patients

Abstract The spectrum of infections caused by methicillin-resistant Staphylococcus aureus (MRSA) ranges from minor to potentially life-threatening. Due to its increased antibiotic resistance, treatment failures are frequent, necessitating novel eradication approaches. In this study, we aimed to isolate MRSA from burn patients, ascertain its antibiogram pattern, and isolate and characterize bacteriophages from sewerage water targeting MRSA. A total of 70 samples were collected from burn patients, and MRSA was identified and characterized using various biochemical and molecular tests, alongside antibiotic sensitivity profiling. MRSA prevalence was found to be 28.6%, with biochemical and molecular analyses confirming its presence. Antibiotic susceptibility testing revealed that 94% of isolates were sensitive to tobramycin and gentamycin, while lowest sensitivity (2%) was observed against vancomycin. Using the soft agar overlay method, three bacteriophages (Phage-1, Phage-2, and Phage-3) were successfully isolated from sewerage water. Among all the phages, Phage-3 demonstrated a broader host range. Furthermore, Phage-3 displayed optimal activity within a pH range of 6–8 and at temperatures between 20–40°C. Phage-3 indicated a rapid decrease in adsorption time within 0–5 minutes, while its one-step growth curve revealed a latent phase lasting up to 30 minutes, followed by a significant increase in titer from 30–50 minutes.