A US woman has died from an infection that was resistant to all 26 available antibiotics, health officials have said, raising new concerns about the rise of dangerous superbugs.

The woman, who was in her 70s, died in Nevada in September, and had recently been hospitalised in India with fractured leg bones.

The cause of death was sepsis, following infection from a rare bacteria known as carbapenem-resistant Enterobacteriaceae (CRE), which is resistant to all antibiotics  in the United States.

Experts said she had been treated repeatedly in India during for a femur fracture and hip problems.

Paul Hoskisson, a researcher at the University of Strathclyde, in Scotland, said that several European countries, including Britain said: “This is important because we are seeing increasing numbers of drug-resistant infections, and this is one of the first cases for Klebsiella where no drug options were open to the medical staff.”

Multi-drug-resistant Klebsiella pneumoniae has been described by the World Health Organization as “an urgent threat to human health.”

According to Nick Thomson, leader of the bacterial genomics and evolution group at the Wellcome Trust Sanger Institute in England, this bacteria is likely to become more and more resistant.

“The report highlights international travel and treatment overseas as a feature in the introduction of this pan-resistant isolate into the USA,” he said.

Laura Piddock, a professor of microbiology at the University of Birmingham, said the case shows that doctors “need the flexibility to use antibiotics licensed for use in other countries and shown to be active in the laboratory against the patient’s infecting bacterium.”