eighteen-month stability of myoviridae bacteriophages under refrigeration temperatures for therapeutic applications

Background: rising antimicrobial resistance, especially in pseudomonas aeruginosa, has renewed interest in myoviridae phages as therapeutic agents. their long-term stability under refrigeration remains a key challenge. this study was conducted to examine the stability and therapeutic potential of three myoviridae bacteriophages (pa45, pa32, and pa6) stored at refrigeration temperatures (approximately 4°c with minor variations) over 18 months. methods:the refrigerator temperature was checked weekly using a manual thermometer. regular enrichment was performed on a monthly basis to maintain phage infectivity. phage titers were measured using the double-layer agar method. results: results indicated that jumbo phage pa32 retained over 90% of its infectivity, pa45 retained about 85%, and pa6 retained approximately 70% of its initial level. conclusion: these findings highlight refrigeration as a viable and practical approach for long-term phage storage, particularly in resource-limited settings.