PORTLAND — Portland Shellfish Co. has entered into a consent decree with the U.S. Food and Drug Administration over unsanitary conditions at the company’s seafood processing plants.

The agreement was signed by Judge John Woodcock in U.S. District Court in Portland. It prohibits Portland Shellfish Co. from distributing its products interstate until the FDA approves its sanitation program. The decree also allows the FDA to order a shutdown or recall.

The decree was filed for food safety violations at the company’s Portland and South Portland plants that process lobster, shrimp and crab. The filing followed two episodes of contamination of cooked lobster meat since 2008. The meat was found to be contaminated by a bacteria that causes listeriosis, a potentially fatal disease for high-risk groups such as newborns and the elderly.

Jeffrey Holden, president and company founder, said his company has since upgraded the plants and safety procedures, which now exceed federal standards.

The company employs about 150 people.