TOKYO • The NDM-1 superbug, which is resistant to almost all antibiotics, has been confirmed for the first time in Japan, it was learned Monday.

NDM-1, whose full name is New Delhi metallo-beta-lactamase-1 — as it was discovered in New Delhi — is an enzyme that can turn bacteria into superbugs resistant to antibiotics.

The infected man was a patient at Dokkyo Medical University Hospital in Mibumachi, Tochigi Prefecture, according to the hospital. The patient, in his 50s, was hospitalized in May last year after returning from a trip to India. At the time, doctors examined the feverish patient and found E. coli with the NDM-1 gene.

The man was discharged after being treated and fully recovering. No in-hospital infections were observed, according to the hospital.

The NDM-1 superbug also has been detected in India, the United States and Europe. The NDM-1 superbug can be spread not only in medical institutions but also among otherwise healthy individuals.

The enzyme can invade different types of bacteria. Bacteria carrying the NDM-1 gene are called superbugs because they are highly likely to affect public health.

Medical experts are concerned about the risk posed by poisonous bacteria such as salmonella and dysentery bacillus becoming resistant to antibiotics.

The World Health Organization has issued an international warning about the NDM-1 superbug.

On Aug. 18, the Health, Labor and Welfare Ministry instructed medical institutions to report suspicious cases to the National Institute of Infectious Diseases.

The ministry also has urged medical institutions to take measures to prevent the superbugs from spreading to other patients and to ask patients about overseas travel.

Since the discovery of bacteria with the NDM-1 gene in India, the gene has spread to Britain and the United States through patients who underwent surgeries in India. The first death directly attributed to NDM-1 was reported in Belgium last month.