Alarmed over the increasing use of antibiotics to treat even common ailments, Nobel laureate Dr John Robin Warren has warned of a "disaster" if excessive use of antibiotics is not stopped.

"I think one of the current issues globally is the increasing use of antibiotics and the increasing resistance to antibiotics. If that keeps growing, we are going to be in real trouble," Warren, who was in Mumbai for the 102nd Indian Science Congress, told PTI.

Speaking on the global perspective on challenges in medical research, Warren who hails from Adelaide in Australia, said, "Doctors should stop prescribing antibiotics when they are not needed.

"Patients also insist to the doctors to prescribe antibiotics for things like cold, even when the doctor knows that the antibiotics is not going to be of any assistance at all. So he (doctor) shouldn't give them to the patient. But people tend to prescribe when the patient demands it," he said.

Asked if he saw a decline in prescription of antibiotics after a report by the World Health Organization (WHO) said resistance to antibiotics poses a "major global threat" to public health, Warren said, "It is a very difficult situation. It is not a disaster yet, but could easily become one."

"I haven't seen things improving (after the WHO report)," Warren said.

Warren awarded the Nobel for his work in Physiology in 2005 for his discovery on the 'bacterium Helicobacter pylori' and its role in gastritis and peptic ulcer diseases.

"When we started on our journey, scientific and technological tools were not advanced. Science believed that bacteria couldn't grow in stomach, good biopsies were rare, and there were no clinical specimens.

"Gastritis was not understood well by the medical fraternity. But we refused to be discouraged, kept experimenting with determination and after years of dedicated hard work, discovered the bacterial strain," he said.

"It was a quite a miracle and opened new vistas in discovering treatments for Gastritis and peptic ulcers for making the life of human beings more productive and healthy," Warren said.