ISOLATION AND CHARACTERIZATION OF BACTERIOPHAGE SPECIFIC FOR STAPHYLOCOCCUS AUREUS

Abstract

      There has been a concerning rise in drug-resistant strains of Staphylococcus aureus. Consequently, a recurring focus has been on alternative antimicrobial treatments, such as bacteriophages.   The present study focused on isolating and characterising a lytic phage that specifically targets S. aureus bacteria found in food.   This study involved the isolation and titration of a phage using the double-layer agar technique. Additionally, the stability of the phage was assessed under various physical and chemical conditions, including temperature, UV light, alcohol, and isopropanol exposure.   The analysis revealed the presence of a lytic phage, which contradicts the presence of an antibiotic-resistant S. aureus. The stock titer of the phage is around 3×1010 PFU (plaque-forming units) per milliliter.   Based on the characterization properties, it was seen that the highest virus titer was achieved at a temperature of 37°C and a pH of 7.2. However, the activity of the bacteriophage decreased rapidly as the temperature increased progressively to 45°C, 50°C, and 55°C, and it entirely lost its activity at 60°C.   The bacteriophage was rendered fully inactive at pH values of 3 and 4 and at pH values of 10 and 11. Additionally, it experienced a partial activity loss at pH values of 5, 6, 8, and 9.   It experiences a 10% isopropanol impact but is more significantly impacted by 70% alcohol.

Keywords: Staphylococcus aureus  phage ; isolation; characterization.