Mycobacterium leprae is the bacterium that causes leprosy.

The cause of his lateness was a train delay.

Hansen's disease is a disease with very weak infectiousness.

He was suffering from leprosy.

In old Japan, leprosy was considered an incurable disease.

This bacterium is resistant to antibiotics.

I learned about bacterial culture in my microbiology class.

He is an expert in bacteriology.

He is a world-renowned bacteriologist.

Archaebacteria are one of the oldest life forms on Earth.