Recently, microorganisms have evolved and grown resistant to antibiotics. Antiviral drugs that hinder pathogens’ ability to reproduce and spread in the body are now becoming less and less effective. Because of this, CRISPR is now being tapped to fight new generation superbugs and the flu.
CRISPR is a gene-editing tool that was used in ways such as to alter mosquitoes to prevent them from spreading malaria and edit tomatoes to make them more flavorful and cure certain human genetic diseases. At present, it now bears a new weight—to help humans fight bacteria and viruses that infect cells.
The next Step in antimicrobial therapy
According to Dr. David Edgell, a biologist at Western University in London, Ontario, CRISPR is the next step in antimicrobial therapy. Edgell and his team conducted a successful study to eliminate a species of Salmonella, forcing it to make lethal cuts to its own genome using a Crispr-associated enzyme called Cas9. They did this by tucking a conjugated plasmid which was encoded with CRISPR instructions inside the E. coli bacteria. As they expected, the CRISPR system wiped out nearly all Salmonella bacteria while leaving E. coli intact.
Mitch McVey, a biologist at Tufts University who was not part of Egdell’s team, pointed out that the study showed a significant advancement in specifically targeting bacteria. Luciano Marraffini, a microbiologist at Rockefeller University and the Howard Hughes Medical Institute, also said that scientists are figuring out the benefits of microbiota for the promotion of good health. Conventional antibiotics cannot distinguish between good and bad bacteria and can eradicate everything randomly, which has a negative effect on people with a weak immune system. Marraffini also adds that by using CRISPR, only specific pathogenic bacteria are killed leaving the rest of the healthy microbes alone.
Developing CRISPR-based antibiotic pills could allow scientists to harness the power of the human body’s own resident microbes in preventing diseases. In fact, a few companies such as Eligo Bioscience, a start-up co-founded by Dr. Marraffini, have started to pursue Crispr-based antibiotics that can be delivered through engineered viruses to prevent them from reproducing or causing infections.
CRISPR Cas13: another work in progress
A study has also shown that another CRISPR enzyme, Cas13, could be programmed to detect and kill influenza A virus, lymphocytic choriomeningitis virus, and vesicular stomatitis virus which are three different single-stranded RNA viruses that infect human cells. The researchers saw a 40-fold reduction in viral RNA within 24 hours as well as a 300-fold reduction for the flu virus.
Rodolphe Barrangou, a microbiologist at North Carolina State University who was not involved in Egdell’s study, looked at the feat as a great proof-of-concept. Barrangou is a co-founder of a CRISPR-based antimicrobial products company. He believes that the researchers who worked on the single-stranded RNA viruses can further design CRISPR technology to treat more deadly viral infections as well. He also said that the challenge is to demonstrate that CRISPR antibacterial and antiviral drugs are effective in living animals and in humans, not just in the laboratory, and are cheaper than conventional therapies.
A new way to treat diseases
CRISPR is easy to tweak as needed compared to current antiviral drugs. According to Cameron Myhrvold, a postdoctoral researcher at Broad, the CRISPR system can easily be changed and match a virus if it evolves and mutates. This looks just like the beginning of something new in the way we treat disease.