The world is in desperate need of new antibiotics, as bacteria continue to evolve and develop resistance to the ones we have. Now, researchers at La Trobe University have found a peptide in the flower of a tobacco plant that could be the first of a brand new kind of antibiotic, hopefully helping us avoid the looming doomsday of superbugs.

Antibiotics were one of the most important scientific discoveries in human history, as the ability to fight infection made routine surgery and common illnesses much less life-threatening. But overuse and overprescription of these drugs has weakened their benefits, to the point where many are no longer effective and we could be headed back into "the dark ages of medicine."

"Infectious diseases are a major global health problem, accounting for more than one in eight deaths and mortality rates are predicted to skyrocket over the next 30 years," says Mark Hulett, an author of a study describing the new find. "Antibiotic resistance at the current rate will eventually lead to the exhaustion of effective long-term drug options. It's imperative we develop new antibiotic treatments."

The search is on, and scientists have already found promising new antibiotic candidates in all sorts of unexpected places, such as rattlesnake venom, platypus milk, berries, honey, maple syrup, human breast milk, fungi and frog skin.

Now we can add tobacco flowers to the list. The ornamental plant Nicotiana alata protects itself from infection by producing anti-fungal molecules, and the La Trobe team isolated a peptide known as NaD1 from the flowers to test if it could be put to work as an antimicrobial agent for human use.

The peptide was found to be effective against a type of microorganism that most antibiotics can't kill – Candida albicans. This common species of yeast is often found in the human gut and mouth and, although it's normally harmless, it can pose a threat to people with compromised immune systems.

In their experiments using the Australian Synchrotron, the researchers found that NaD1 destroyed the fungus in an effective, violent manner – by puncturing the outer cell walls and ripping them open.

"They act in a different way to existing antibiotics and allow us to explore new ways of fighting infections," says Hulett. "It's an exciting discovery that could be harnessed to develop a new class of life-saving antimicrobial therapy to treat a range of infectious diseases, including multi-drug-resistant golden staph, and viral infections such as HIV, Zika virus, Dengue and Murray River Encephalitis."

The research was published in the journal Nature Communications.