Crocodiles Fungal Infections Medicine, crocodiles are protected from protein fungal infections, medicine can be made for humans, revealed in latest research

Melbourne: Different species of alligators have been living on the earth for millions of years and in this journey they have developed disease resistance in a very special way. This helps them to defend against harmful microorganisms present in their habitats in swamps and other water bodies. Our study, recently published in Nature Communications, investigated the antimicrobial proteins ‘defensins’ found in saltwater crocodiles. This protein plays a key role in fighting/preventing infectious diseases in alligators. As the number of antibiotic-resistant microorganisms grows, so does our need for new and effective treatments.

Will the defensins protein found in these crocodiles become the answer to these questions and be helpful in developing life-saving drugs? What are defensins? Defensins are proteins produced in very small amounts in plants and animals. In plants, defensins are generally produced in flowers and leaves, whereas in animals, they are produced in white blood cells and mucus membranes (membranes of the lungs and intestines). Their role is to protect the body by killing infectious microorganisms. The study of defensins found in different species of plants and animals has shown that they can fight against a wide range of disease-causing microorganisms. These microorganisms include bacteria (bacteria), fungi, viruses (viruses) and even cancer cells.

Defensins usually kill these microorganisms by binding to their cell membranes. Defensins, after coming in contact with these microorganism cells, pierce their cell membrane, due to which the microorganism inside the cell starts leaking and eventually it dies. What is special about the defenses of alligators? Gharials rarely get infected despite living in dirty water, while they are often injured during hunting and fighting over their territories. This indicates that the disease resistance of alligators is strong. We want to better understand how defensins have evolved over time in order to protect them in these difficult places.

In the course of studying the genome of saltwater crocodiles, we found a specific defensin ‘CPOBD13’ that can effectively kill the fungus called Candida albicans. Candida albicans is the main cause of fungal diseases in humans worldwide. Although some plant and animal defensins have been shown to kill Candida albicans before, the way ‘CPOBD13’ kills this fungus makes it unique. This is because ‘CPOBD13’ can self-regulate its activities depending on the pH of its surrounding environment. Defensins are inactive at neutral pH (eg, the pH of blood). But, as soon as it reaches the site of infection, it becomes active and starts fighting the infection because the pH there is low and acidic.

This is the first time such activity has been observed in Defensins. Our team discovered the activities of CPOBD13 by elucidating its structure using X-ray crystallography. Is fungus really a threat to human health? Compared to infections caused by bacteria and viruses, fungal infections are not taken seriously, as all pandemics in human history have been caused by bacteria or viruses. The truth is that fungus is commonly seen as an infection in the nails and feet of players, etc., which are not life-threatening. But fungus can harm human health, especially those people who have weak immunity. Around 1.5 million people die from fungal infections worldwide every year.

(Scott Williams and Mark Hulett, La Trobe University)