Antibiotic resistance is when bacteria change to resist antibiotics, making certain bacterial infections difficult to treat.
But an international team of researchers, led by University of Otago microbiology and immunology researcher Professor Peter Fineran, have been investigating a particular protein used by certain viruses (known as phages) that can infect and kill bacteria.
He said researchers in other countries had used phages to treat people with antibiotic-resistant bacteria, with very promising results, but it was still very early stages.
"There are still times when it doesn’t work and people often don’t understand why it doesn’t work.
"One of the reasons why sometimes these phages might not work is that bacteria have their own immune systems that can block phages.
"But phages are smart as well, and they also have their own systems to overcome that — nature finds a way," Prof Fineran said.
"We are trying to understand how these phages naturally overcome these hurdles in the bacteria, to successfully infect and kill that bacteria. Then we’ll have a better understanding of how they might be able to be used as antimicrobials.
"There’s a lot of potential to use these phages as antimicrobials — or a new sort of antibiotic."
Prof Fineran said the "big surprising finding" was a protein that phages used when overcoming the immune system of bacteria.
It had an "incredible form of regulation" that had never been seen before in nature.
"These proteins are very common across many different organisms and we’ve found a very novel new way that they can function.
"It essentially means that people will need to now think about how these proteins that are found in bacteria and in humans can have different ways of working than we previously thought."
Lead author and University of Otago microbiology and immunology researcher Dr Nils Birkholz said it could also be used in agriculture, to fight plant pathogens in crops.
It would allow orchardists and crop farmers to gain much higher yields, without using toxic chemicals, he said.
Understanding how phages interact with bacteria was an important step on the path to using phages against bacterial pathogens.
"Specifically, we need to know about the defence mechanisms, such as CRISPR, that bacteria use to protect themselves against phage infection, not unlike how we use our body’s immune system against viruses, and how phages can counteract these defences.
