OCT 06, 2019 8:40 AM PDT

Using CRISPR to Alter or Kill Bacteria

WRITTEN BY: Carmen Leitch

In recent years, the gene-editing tool CRISPR/Cas9 has been applied to a wide variety of different organisms and has started a biomedical revolution. The method was created using a defense technique that bacteria have to battle viruses that infect them. In that time, genetic analysis tools have allowed us to reveal the importance of the microbial community we carry in and on our bodies, especially in the gastrointestinal tract - the gut microbiome. Now scientists want to bring these tools together.

This is David Edgell, PhD, Greg Gloor, PhD, and Bogumil Karas, PhD. / Credit: Schulich Medicine & Dentistry, Western University

Scientists at Western University have now created a method for sending the CRISPR/Cas9 gene editor into microbes, which can enable us to target specific types of bacteria in different ways. The work has been reported in Nature Communications.

The gut microbiome has been connected to a variety of diseases and disorders. Researchers have been learning more about how specific types of bacteria are related to the development of certain diseases, and how we can turn a gut microbiome that promotes illness into a healthy one. This research can also help us find ways to eliminate pathogenic microbes that don’t involve antibiotics.

"One of the major reasons that I am excited about this work is that it has a wide range of possible real-world applications," said Bogumil Karas, Ph.D., an Assistant Professor at Western's Schulich School of Medicine & Dentistry. "It has the potential for [the] development of next-generation antimicrobial agents that would be effective even for bacteria that are resistant to all known antibiotics. This technology could also be used to help 'good' bacteria produce compounds to treat diseases caused by protein deficiencies."

In bacteria, CRISPR attacks invading viruses by chopping up the viral DNA. Bits of that DNA are then integrated into the bacterial genome to create a kind of memory of the invader. Scientists have modified it so that specific places in the genome can be selected for editing, and it has been used to edit the genomes of cells, research animals, and in some cases, even humans. Now it can zero in on specific types of bacteria.

"Using CRISPR to kill things isn't a new idea because that's what CRISPR does naturally," said David Edgell, Ph.D., Professor at Schulich Medicine & Dentistry. "The problem has always been how you get CRISPR to where you want it to go. Other delivery systems could only go to a few spots, where ours can go anywhere."

Bacteria naturally like to share DNA. One way they do that is bacterial conjugation or direct contact between two bacterial cells (an example is shown in the video above). In this work, the researchers grew two kinds of bacteria, Escherichia coli and Salmonella enterica, together, and showed that a plasmid containing the CRISPR reagents could be shared between them. The S. enterica microbe could be efficiency killed off by targeting certain non-essential genes in the bacterium, changing its DNA and killing it.

Sources: AAAS/Eurekalert! via University of Western Ontario, Nature Communications

 

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
AUG 28, 2020
Microbiology
As Buildings Reopen After Lockdowns, They Find Legionella
AUG 28, 2020
As Buildings Reopen After Lockdowns, They Find Legionella
Several schools and even buildings at the Centers for Disease Control and Prevention (CDC) have identified Legionella ba ...
SEP 11, 2020
Chemistry & Physics
Indigenous fermentation processes require complex chemical reactions
SEP 11, 2020
Indigenous fermentation processes require complex chemical reactions
A study published in the Nature journal Scientific Reports uncovers the complex chemical processes behind aborigina ...
SEP 28, 2020
Microbiology
The Flu Vaccine Will Not Increase the Risk of COVID-19
SEP 28, 2020
The Flu Vaccine Will Not Increase the Risk of COVID-19
Scientists and clinicians want people to get their flu shots this year, especially because of the ongoing pandemic.
OCT 25, 2020
Microbiology
Over Time, Plague Infections Spread Faster
OCT 25, 2020
Over Time, Plague Infections Spread Faster
From the time of the Black Death, around 1348 and the Great Plague of 1665, epidemics of plague occurred in Europe. Rese ...
OCT 29, 2020
Microbiology
Metabolomics and the Microbiome
OCT 29, 2020
Metabolomics and the Microbiome
The average person contains large variations in bacteria from the mouth, the skin, sweat, and in the stomach and intesti ...
NOV 02, 2020
Microbiology
A Bacterial Virus Can Help Salmonella Spread
NOV 02, 2020
A Bacterial Virus Can Help Salmonella Spread
The Salmonella bacterium is to blame fora lot of foodborne infections, many of which cause only mild illness, though oth ...
Loading Comments...