Swiss scientists have found a new class of antibiotics, offering drug developers a fresh weapon in the fight against multi-drug resistant bacteria or "superbugs."

Researchers from a privately held Swiss biotech company Polyphor and the University of Zurich said the potential medicines are effective against a type of bacteria known as "gram-negative," and offer hope for new treatments for serious and often life-threatening infections.

The antibiotics work by deactivating a protein vital for the formation of the bacteria's outer cell membrane.

Polyphor's chief financial officer said the firm was in talks with pharmaceutical firms about possible licensing deals on the most advanced drug candidate, called POL7080, which selectively kills the dangerous pseudomonas aeruginosa, a common bacteria that can cause lung infections.

"There is a big need for new antibiotics that can overcome rising resistance," Michael Altorfer told Reuters. "And if you look back in history, finding a new class of antibiotics is an event that probably happens about every 20 years."

Until recently, antibiotics have been viewed by drug makers as a low-growth area but the emergence of superbugs has rekindled interest in the field.

A study published in the journal Science found that POL7080 was able to target and deactivate an essential protein of the pseudomonas bacteria, killing the bug.

A report in December found that gram-negative bacteria account for around 63 percent of infections in hospital intensive care units. Experts commenting on that study said they feared resistance among gram-negative bugs was rising while the number of medicines to treat them was shrinking.

Drug-resistant bacteria kill about 25,000 people a year in Europe and about 19,000 in the United States.

Altorfer said Polyphor is planning to start Phase I clinical trials in healthy volunteers in the second quarter of this year and had begun out-licensing negotiations with potential pharma partners. He declined to name any of the firms in talks.

Pseudomonas aeruginosa is a particular problem in hospital acquired infections and in patients with cystic fibrosis, whose lungs and digestive systems become clogged with a thick, sticky mucous.

Altorfer said he was keen not to raise hope, but the drug could potentially be made in an inhalable form to help cystic fibrosis patients, of which there are around 70,000 worldwide.

"But there are other indications that could come first, such as hospital acquired infections," he said.

U.S. biotechnology firm Gilead Sciences is developing a drug called aztreonam for the treatment of lung infections in cystic fibrosis patients caused by pseudomonas aeruginosa.