Phages are an abundant and diverse group of viruses that can attack bacteria. Past studies have demonstrated success with the use of phages for the treatment of bacterial infections. However, researchers still lack understanding of the process by which phages attack and kill pathogens. Thus, a study was conducted by researchers to examine the mechanism by which phages attack the bacterium Salmonella Typhi.
A study by Hardy and colleagues at Monash University examined the mechanistic action of how phages attack Salmonella Typhi, a disease-causing agent of typhoid, using cryo-electron microscopy. Researchers demonstrated that phages assemble their head and tail by curling around each other to form an elongated chain. The head, a capsid, is filled with viral DNA that allows for stability while the tail contains hexameric rings that promote flexibility in injecting the bacteria with phage DNA.
Phages and Antibacterial Resistance
Antimicrobial resistance has become a prominent public health care crisis. A report by the Centre for Disease Control and Prevention (CDC) estimated that at least 2.8 million people get an antibiotic-resistant infection annually in the United States. Over the past decade, antimicrobial resistance has continued to spread at an unprecedented rate. Multiple reasons for this include the horizontal gene transfer of genetic components encoding resistance between bacteria and the disruption of the growth pathway that results in a high evolutionary pressure to select for resistant mutants.
The current study by Hardy and his team has given researchers hope in the use of phages in the fight against antimicrobial resistance. Furthermore, researchers might potentially be able to target specific phages to treat a wide variety of bacterial infections. This approach will promote individualized medicine as Professor Lithgow stated: “This finding will help us overcome one of the most critical hurdles in phage therapies which is a precise understanding of how phage work, in order to predict in advance and select with accuracy the best phage for each patient infection.”
In conclusion, the present study illustrated the mechanistic underpinnings of how phages eliminate bacterial infections. The understanding of this mechanism can open the door to the development of novel therapeutic strategies to combat antimicrobial resistance. Future studies should aim to conduct clinical trials in humans to investigate the safety and effectiveness of phages in the treatment of bacterial infections.