Smart researchers use lysins to selectively target bacteria

Researchers from the Antimicrobial Resistance (AMR) Interdisciplinary Research Group (IRG) at Singapore have developed a method to produce customizable engineered lysins that can be used to selectively kill bacteria of interest while leaving others unharmed. The discovery presents a promising alternative to antibiotics for treating existing drug-resistant bacteria and bacterial infections without the risk of causing resistance. Lysins are enzymes produced by bacteriophages to break open the bacteria cells while treating infections, and have demonstrated potential as a novel class of antimicrobials. A major advantage of lysins is that they allow fast and targeted killing against a specific bacterium of choice without inducing resistance. The emergence of multidrug-resistant bacteria  has left even minor bacterial infections incurable by many existing antibiotics, with at least 700,000 deaths each year due to drug-resistant diseases, according to the World Health Organization.

In a paper titled “Engineered Lysins with Customized Lytic Activities Against Enterococci and Staphylococci” recently published in the prestigious journal Frontiers in Microbiology, the SMART AMR team demonstrates one of the methods to customize the lytic spectrum of engineered lysins.

The study reveals how the engineered lysins were able to selectively kill bacteria such as staphylococcus Enterococcus faecalis, while leaving the Enterococcus faecium bacteria of the same genus unharmed. This is the first report of a chimeric lysin that can both target bacteria of multiple genera and selectively kill one bacterial species within a genus over another.

The human body contains trillions of bacteria, which form the microbiome, and the majority of the bacteria is either harmless or beneficial to us. What happens when we are on an antibiotic course is that the antibiotics kill all of the bacteria, leaving us vulnerable to a worse reinfection after we have completed the antibiotic course. Since lysins respect the microbiome and only eliminate the bad pathogenic bacteria, they are a very promising alternative for treating bacterial infections.

Since lysins are essentially proteins, they can be engineered and mass produced. This study clearly shows how modifying these proteins translates to improvements of their specificity and antibacterial activities.

In the lab it has been observed that once a small amount of lysin is added, it only takes 30 minutes to completely kill the bacteria, making them a very safe and efficient choice for removing unwanted bacteria. While developments in the production of customized lysins would greatly impact pharmaceutical industries where lysins can be used to treat bacterial infections, skin-care and consumer care industries would also benefit by using lysins as a targeted agent to remove unwanted bacteria from their products.

Source: 
https://news.mit.edu/2020/smart-researchers-use-lysins-selectively-...

https://researchnews.cc/news/4087/SMART-researchers-use-lysins-to-s...