PROVIDENCE, R.I. — Black pepper used to coat salami is the possible cause of a salmonella outbreak that sickened people in 40 states, including Washington, the Rhode Island Department of Health said today.

Tests showed the same strain of salmonella that has sickened at least 189 people since July was also found in two open containers of pepper at meat company Daniele International Inc.’s facility in Burrillville. Thirty-seven people have been hospitalized in the outbreak, according to the federal Centers for Disease Control.

Annemarie Beardsworth, a spokeswoman for the Rhode Island health department, said officials there are still waiting for results from closed containers of pepper, which are expected in two to three days.

“We’re pretty sure right now that the ground pepper is the source of the outbreak, but until we get a positive result that was taken from a closed container, we can’t be 100 percent certain,” she said.

Daniele International recalled 1.2 million pounds of pepper-coated salami on Saturday after officials used the shopping records of people who were sickened to pinpoint the source of the problem.

The Department of Health said no additional products were being recalled.