Using phages to control mycobacterial infections

– Edna George

Mycobacterial infections pose a serious threat, partly due to the emergence of antibiotic resistance. Although treatment strategies are in place to control mycobacterial infections, drug-resistant mycobacteria are on the rise, underscoring the importance of looking for alternative strategies. In a new study, researchers at the Centre for BioSystems Science & Engineering have shown that bacteriophages can offer a possible solution to fend off mycobacterial infections.

Bacteriophages are viruses that infect, live and multiply inside and finally kill bacteria. Some bacteriophages have been used successfully to treat bacterial infections associated with cystic fibrosis. The IISc team, therefore, decided to explore the possibility of using a similar therapeutic strategy to treat mycobacterial infections.

To begin with, studies were carried out to understand the growth kinetics of mycobacteria in the presence of phages when cultured under conditions similar to those seen in infection sites in humans, such as an acidic environment, low oxygen levels and limited nutrient conditions.

Under these conditions, the phages were found to effectively kill the bacteria. This was identified by the zone of clearance in a lawn culture of mycobacteria as well as by the decrease in the optical density and colony forming units of phage-treated mycobacterial cultures. Further studies showed that a cocktail of phages could effectively inhibit the growth of mycobacteria. They also showed that this phage therapy can be combined with existing drugs to provide a synergistic outcome to control mycobacterial infections. More importantly, phage therapy was effective against drug resistant mycobacteria as well.

The findings, therefore, highlight the potential of phage therapy to treat diseases caused by mycobacteria, such as tuberculosis.

Reference

Kalapala YC, Sharma PR and Agarwal R (2020) Antimycobacterial Potential of Mycobacteriophage under Disease-Mimicking Conditions. Front. Microbiol. 11:583661. doi: 10.3389/fmicb.2020.583661

Lab website

https://be.iisc.ac.in/~rachit/