The science of bacteriophage and the future of fighting bad bacteria

Photo © iStockphoto.com/Artem_Furman

The use of bacteriophage is the future of fighting antibiotic resistant bacteria. A bacteriophage is a virus that targets specific host bacteria, multiplies within it, destroys the host, and then its duplicates search out more hosts. Nutritional Outlook recently reported the positive results of a study researching the positive effect of a bacteriophage cocktail product from Deerland Probiotics and Enzymes (Kennesaw, GA) on healthy gut microbiota, but research into bacteriophage use for medical applications against deadly bacteria continues.

Researchers at the University of Alabama, for example, identified a bacteriophage called Andhra in 2015 that attacks Staphylococcus, otherwise known as staph. Research into bacteriophage has led to the discovery of CRISPR-Cas systems, used by bacteria to defend themselves from viral attacks. When bacteria with CRISPR-Cas systems are exposed to a virus, CRISPR captures a strand of the virus’s DNA, transforms it into RNA that is fed into CRISPR enzymes, which wait for the next invader. These enzymes then use the genetic information from the initial virus to seek out, identify, and destroy organisms matching that genetic information.

Readers may be familiar with CRISPR because it has been harnessed by scientists as a gene-editing tool. In this context, researchers are trying to understand how specific viruses like staph use CRISPR-Cas to mount a defense against bacteriophage, thus compromising bacteriophage’s otherwise promising therapeutic effects. In a recently published study, researchers from the University of Alabama identified two enzymes in the CRISPR-Cas system of Staphylococcus epidermidis that played crucial roles in its defense response against bacteriophage: PNPase and RNase J2. Previous research showed that these enzymes were usually used to degrade damaged genetic material, which, researchers explain, means that the CRISPR-Cas system in Staphylococcus epidermidis has evolved to coordinate with another pathway to survive attacks by bacteriophage.

Understanding the way a specific CRISPR-Cas system functions is the first step in being able to harness CRISPR against the bacterium’s own immune system by equipping bacteriophage with their own CRISPR systems. As research into bacteriophage continues and our understanding of their use against problem bacteria improves, we can expect more bacteriophage use in dietary supplements, improving gut microbiome and immune defenses, while the medical community perfects bacteriophage use against antibiotic resistant bacteria.
 

References:

1. Chou-Zheng L et al. “A type III-A CRISPR-Cas system employs degradosome nucleases to ensure robust immunity.” Microbiology and Infectious Disease, Published online ahead of print on April 3, 2019