A York woman whose son became ill after eating beef contaminated with E. coli bacteria has filed a lawsuit in Maine alleging negligence on the part of a family-owned farm in New Hampshire that was the source of the beef.

Sarah Monks filed the lawsuit on behalf of her 9-year-old son in York County Superior Court in Alfred on Thursday. It also accuses PT Farm of North Haverhill, New Hampshire, of product liability and breach of warranties.

Monks cooked ground sirloin for her son, identified in court records only by his initials C.H., on June 13, and then five days later he became so sick with vomiting, diarrhea and fever that he was hospitalized for multiple days, first in Maine and then at Boston Children’s Hospital in Massachusetts, according to the lawsuit.

Monks’ son was one of 14 people who became sickened between June 15 and July 10 after an E. coli outbreak at the PT Farm that was identified by the U.S. Department of Agriculture’s Food Safety and Inspection Service, prompting a recall of 8,800 pounds of raw beef in late July.

Monks’ son was the only person from Maine who became sickened as a result of the contamination. The others who became ill included 10 people from New Hampshire, two from Massachusetts and one from Vermont, according to the U.S. Department of Agriculture.

“It is the responsibility of all food manufacturers to protect their customers against foodborne illness,” Monks’ attorney, Bill Marler, whose firm in Seattle specializes in foodborne illnesses, said in a written statement. “This means 365 days a year. All of the illnesses in this outbreak can be traced back to a single slaughter day. This almost perfect record was enough to cause suffering for many, including children. Being almost perfect simply isn’t good enough when it comes to food safety.”

Monks is also represented by a local attorney, Peter Felmly, of the Portland firm Drummond Woodsum.

No one returned a phone message left at PT Farm seeking comment on the court case.

E. coli is a potentially deadly bacteria. Most people recover after exposure to the organism within a week, but some can develop kidney failure, particularly children under 5 and older adults, according to the U.S. Department of Agriculture.