"The situation is alarming because healthy individuals may have been unknowingly spreading this superbacteria for years. Salmonella is one of the major micro pathogens of food poisoning and can cause diarrhea and vomiting. A drug-resistant version could pose a serious threat to public health."

Kan added that the superbug has the possibility of becoming an epidemic, similar to the typhoid outbreak in the early 20th century, when a healthy female carrier, Mary Mallon, is believed to have infected two dozen people with typhoid fever while displaying no symptoms.

Since its discovery in 2015, the MCR1 gene has spread to more than 30 countries, including the United States, the United Kingdom, Canada, India and Malaysia, according to Kan.

"The MCR1.6 gene or other MCR1 gene variants might begin to appear in other countries," he warned. "A conservative estimate of more than 3 million Chinese suffer from Salmonella-related illnesses each year, with children and the elderly most at risk."

Salmonella outbreaks also occur in the US on a regular basis, with the last major outbreak in late November, according to the US Centers for Disease Control and Prevention.

To tackle the superbug issue, governments should strictly regulate the use of antibiotics in livestock farming, educate the public on antibiotic uses, strengthen surveillance of resistant bacteria, and promote research and development of new antibiotics, Kan said.

For the general public, "something as simple as washing your hands, cooking food properly and strictly following a doctor's prescription for antibiotics can greatly reduce the chance of catching a serious infection", he added.