They're two millionths of a metre, and they can be found outside, as well as on your skin, even inside your nose, throat, and gut.

The World Health Organization calls Klebsiella pneumoniae a major concern, because this tiny bacteria can cause deadly infections.

Molecular microbiologist Jenny-Lee Thomassin recently arrived at the University of Saskatchewan to study one of the most drug-resistant strains of Klebsiella pneumoniae.

"Bacteria are constantly changing," said Thomassin. "What seems to be emerging in some places are crosses between classic and hypervirulent strains, where antibiotic-resistant bacterium can make a healthy person sick."

Hear why she likens her work to fixing a car engine blindfolded.