The study, conducted by La Trobe University researchers, took a closer look at antimicrobial proteins called defensins found in saltwater crocodiles. It involved harvesting tissue from crocs from Koorana Crocodile Farm in Yeppoon, Queensland to better understand how their defensins have adapted over time to protect them in these harsh environments. 

It is hoped the findings could eventually be used to create a targeted treatment for fungal infections in humans – a problem that is becoming more frequent due to growing antibiotic resistance.

Why croc's?

Defensins, which are small proteins made by the white blood cells and in mucous membranes in the lungs and intestines, play a key role in protecting the reptiles by killing infectious organisms including bacteria, fungi and viruses.
Lead author Scott Williams said that while bacterial and viral infections are typically viewed by Australians as being of far greater concern than fungi, their danger should not be underestimated as they can pose severe problems to human health, particularly in people with impaired immune systems.
Globally, around 1.5 million deaths per year are attributed to fungal infections.

Williams said the study discovered that crocodile defensins were surprisingly similar to the same proteins in humans, the first time this function has been found in any plant or animal.

How it helps

“Some therapeutic treatments act on healthy cells by accident whereas this mechanism could help to reduce these off-target effects and focus on what’s harmful.”
It is hoped the findings of the study could allow researchers in the future to engineer defensins with pH-dependent activity in biotechnology and therapeutic applications, like treating serious infections in humans.