The Cape Breton District Health Authority says the cases of MRSA (methicillin-resistant Staphylococcus aureus) were discovered during routine infection control surveillance at the Glace Bay Hospital.
The authority says the bacteria is hard to treat because it is resistant to most common antibiotics, though it can be treated with proper medication.
The six people are patients on the acute care floor.
For the time being, only immediate family or next of kin will be permitted to visit patients on the floor, and only two visitors at one time.
People who are sick or live with others who are sick are asked not to visit.