By using virus that infects bacteria (bacteriophages), researchers from Panjab University have successfully treated multidrug-resistant bacterial infection in diabetic mouse model. People with diabetes are more prone to fungal and bacterial infections and the emergence of multidrug-resistant organisms has worsened the situation. Researchers have been searching for alternative treatment approaches such as phytochemicals, metal ions, antibacterial nanoparticles, antibacterial enzymes. The phage therapy has shown promising results among various alternative treatments studied.
Phage therapy
“Phage therapy or use of a specific virus to target particular bacteria was in use in many countries before the popularisation of antibiotics. Even now it is used in Russia, Georgia, Poland and other countries. Though it is currently not used in India, it is an option we should choose as there is an increase in the number of drug-resistant pathogens in our country,” explains Prof. Sanjay Chhibber from the Department of Microbiology, Panjab University and first author of the paper published in Frontiers in Microbiology.
In order to protect the phage and help in its slow release into the body, the researchers encapsulated the phage in a natural lipid casing called liposome. The liposome entrapped phage was injected into diabetic female mice to treat methicillin resistant Staphylococcus aureus -infected wound and the healing was studied for 20 days.
The healing was studied in four different groups of mice. One was not given phage or clarithromycin, one was given phage cocktail but not encapsulated, other was given liposome-loaded cocktail of bacteriophages and the last was treated with clarithromycin only.
The group treated with the liposome-entrapped phage showed a significant decrease in the wound size on day five itself and complete closure of wound was seen by day nine. The study showed liposome-loaded phage eradicated bacterial infection in 10 days whereas untreated mice showed high bacterial burden.
The researchers also studied the inflammatory markers (myeloperoxidase) produced by neutrophils at the wound site. These are the first cells that reach the site of infection or inflammation. So studying neutrophils or its markers is suggestive of the level of inflammation or bacterial load. The level was lowest in the liposome entrapped phage-treated group, which indicated the clearance of bacterial infection. This group also showed maximum deposition of mature collagen tissues at the site of the wound by day five, thus aiding in rapid wound healing.
“Phage therapy can be used as a personalised therapy where the patient is first tested for bacterial infection and then treated with the appropriate phage. Also, it is very effective compared with antibiotics as it requires only a single dose, and its concentration does not decrease as long as it has the bacterial host,” he adds. “Phages are very safe and non-toxic. They are in our system, we encounter them each day in our food and water. Phages have no effect on humans as their host is bacteria, not us.”
