Kiwis seek out superbug weapon

When one collides with a host, a small amount of DNA inside it is thrust into the victim and quickly takes over the cell's machinery, replicating itself hundreds of times. Photo / Getty Images

Scientists here and overseas work on identifying organisms which could one day replace antibiotics.

Kiwi scientists are investigating how tiny organisms found all around us could be turned against the next superbug to hit the country.

In a new partnership with the Howard Hughes Medical Institute in the United States, Massey University researchers are joining a global scientific effort to discover new forms of what are called bacteriophages.

A kind of virus that infects only bacterial cells, these microscopic bugs are the most common biological entity on the planet and are made up of a simple protein capsule.

When one collides with a host, a small amount of DNA inside it is thrust into the victim and quickly takes over the cell's machinery, replicating itself hundreds of times.

Massey microbiologist Dr Heather Hendrickson, who is overseeing the work, said these could potentially replace antibiotics in the future, and be used to combat disease-causing bacteria - including superbugs.

"We are still coming to terms with the problem but by 2050 the number of deaths due to superbugs is predicted to exceed cancer - and this is expected to be highest per capita in Asia," she said.

"In the Western World, the possibility of phage therapy is a largely untapped possible resource that we may draw on in the future."

For now, research involves isolating and sequencing as many different phages as possible, so scientists have a well-understood stockpile that could be deployed against future outbreaks.

Scientists are targeting phages closely related to Mycobacterium tuberculosis - considered one of the top infectious killers and increasingly becoming resistant to multiple antibiotics - and have described more like it than any other form of bacteriophage.

Fonterra, which was at risk from certain entities that could halt production in plants if they managed to infect fermentative bacteria, is also researching potential counter-bacteriophages.

At Massey, undergraduate students in Dr Hendrickson's programme were learning how to search their local environment for viruses capable of destroying a safe bacterial strain in their laboratory classroom, and have so far discovered six new ones.

"By choosing a bacterium that is the safe cousin of a pathogen, students might be finding phages that can kill more dangerous strains of bacteria, without being around those more dangerous strains themselves," Dr Hendrickson said.

Students were learning how to discover, name and purify a novel phage, before sequencing its DNA and annotating the genes within it.

What are phages?

• A type of virus that infects only bacterial cells. Made up of a simple protein capsule that contains a small amount of DNA.

• When it collides with a bacterial host, it thrusts the DNA inside it, taking over the cell's machinery.

• Have been used to counter diseases and could eventually replace antibiotics. Scientists aim to use them against superbugs.