EFFECT OF PH & TEMPERATURE VARIATIONS ON PHAGE STABILITY – A CRUCIAL PREREQUISITE FOR SUCCESSFUL PHAGE THERAPY

Phage therapy has become a successful alternative to conventional antibiotic therapy due to the increasing number of multidrug-resistant bacteria in most clinical settings. Various factors like phage adsorption to the host site and phage neutralization by the host determine the efficacy of phage treatment. However, external factors like temperature and pH are critical in deciding the success of using phages in therapeutics. The high stability of phages under both favourable and unfavourable conditions guides their stability in phage therapeutic preparations as well as at the site of infection. In the present study, we exposed the phage to different pH and temperature combinations. The phage showed statistically significant activity at pH 7 and 8 compared to pH 6. In terms of different exposure temperatures, the phage showed good antibacterial activity at temperatures between 31 ⁰C and 40 ⁰C. A combination of pH 7 with temperature 38⁰ C showed the highest recovery of the phage; however, stability was seen in a considerable range of temperature and pH. The lytic activity of phage was insignificant at extremes of temperature and pH. The present study results indicate that phages, in terms of their stability to variations in external factors, can be a promising alternative to antibiotics or can be used in combination with antibiotics for the successful treatment of multidrug-resistant pathogens.