"I think it's concerning. We have relied for so long on just newer and newer antibiotics. But obviously the bugs can often [develop resistance] faster than we can make new ones," he added.
The sample sent to the CDC was found to contain New Delhi metallo-beta-lactamase (NDM), an enzyme that makes bacteria resistant to many antibiotics.
According to the CDC, "pan-resistant" bacteria are very uncommon, and "infection control contact precautions" are important in such situations, meaning patients will be isolated.
A different superbug was found in at least four patients in the US last year. It was found to be resistant even to colistin, considered the last resort among antibiotics because of its harmful side effects.
Fortunately that bug, known as mcr-1, was not found to be highly contagious.
The CDC considers antimicrobial resistance "one of the most serious health threats" currently facing the US.
• This story was originally published in the The Daily Telegraph