Isolation and Characterization of bacteriophage against Methicillin- resistant Staphylococcus aureus isolated from bedsore and diabetic wounds

Background and Aim : Methicillin-resistant Staphylococcus aureus (MRSA) is a major human pathogen causing a variety of diseases. The potential of bacteriophages as an alternative treatment for MRSA infections has recently gained lots of attention. The purpose of this study was to isolate and characterize bacteriophages effective against clinical isolates of MRSA. Methods : Bacteriophage was isolated from Mofid children's hospital sewage in Tehran. Lytic activity was determined with a spot test, while the titers of phage lysates were measured using the Double-Layer Plaque Assay. The phage characterization was determined through transmission electron microscopy (TEM), adsorption rate, and stability tests to various agents such as the pH, temperature, NaCl concentration, and chloroform. The spot test was used for host range determination and the latent period and burst size were estimated from a one-step growth curve. The effect of bacteriophage against ۱-۳-۵-day old preformed MRSA biofilm was determined using TTC assay.Results : The isolated lytic bacteriophage formed small clear plaques. TEM results revealed that the phage resembled the Cystoviridae family. The latent period of phage was ۳۰ min, corresponding to about ۷۱/۴۳ phage particles per infected cell. The phage was resistant to chloroform and was most stable at ۳۷ °C, pH ۷. By increasing the NaCl concentration, the rate of phage survival decreased. Furthermore, in the first ۵ minutes, the phage exhibited rapid adsorption to the bacteria. This phage had a broad host range and infected ۸۰% of clinical isolates of MRSA. The phage dispersed preformed MRSA biofilm.Conclusion : The isolated phage has the potential to be used as a therapeutic agent against MRSA infections.

کلیدواژه ها:

Methicillin-resistant Staphylococcus aureus ، Bacteriophage ، Phage therapy ، Wound