Federal officials Thursday urged stores and consumers to check any ground turkey they have on their shelves or in their freezers to make sure it is not among the products being recalled because of a nationwide outbreak of a dangerous strain of salmonella.

The salmonella, known as the Heidelberg strain, is resistant to many commonly used antibiotics, making it more difficult to treat, officials said. As a result, an unusually high proportion of those sickened so far have been hospitalized. At least one person has died.

On Wednesday, the Agriculture Department and Cargill announced that the company was recalling 36 million pounds of fresh and frozen ground turkey because of possible contamination from salmonella. The meat was processed at the Minnesota-based company’s Springdale, Ark., plant between Feb. 20 and Aug. 2. The contamination is now linked to 78 illnesses and one death.

This is the third largest meat recall on record, according to David Goldman of the Agriculture Department.

The company also suspended production at the facility “until it is able to to determine the source” of the contamination and “take corrective actions.”

The turkey was sold under several brand names, including Honeysuckle White, Riverside Ground Turkey, Natural Lean Ground Turkey, Fit & Active Lean Ground Turkey, Spartan Ground Turkey and Shady Brook Farms Ground Turkey Burgers. The recall includes products packaged under the HEB, Safeway, Kroger, Randall’s, Tom Thumb and Giant Eagle grocery store brands. All of the recalled brands include the code “Est. P-963.”

The illnesses occurred in 26 states between March 1 and Aug. 1, according to the federal Centers for Disease Control and Prevention in Atlanta, which is helping investigate the outbreak. Twenty-two people have been hospitalized, the CDC’s Chris Braden said.

“This antibiotic resistance may increase the risk of hospitalization and can sometimes contribute to treatment failure,” Braden said.

The most cases have occurred in Michigan and Ohio, which each have reported 10. Texas has reported nine illnesses; Illinois, seven; California, six; and Pennsylvania, five. No cases have been reported in Virginia, Maryland or the District.

Although investigators noticed clusters of salmonella as early as May, and detected salmonella in ground turkey as early as April, the recall did not occur until investigators traced several of the cases in Ohio and Michigan to turkey produced at the Cargill plant late last month, officials said during a briefing Thursday.

Officials have not yet determined how the contamination may have occurred at the plant.

Food safety advocates criticized federal officials for failing to alert the public more quickly.

“I think the government’s handling of this outbreak and recall has been pathetic,” said an e-mail from William D. Marler, a Seattle attorney who represents food-poisoning victims.

Some members of Congress and consumer advocates also said the outbreak underscores the need to improve the food-safety system.

“This massive recall is yet another example of how critical it is to fully fund and support the agencies that are responsible for protecting our food supply,” said Rep. Rosa L. DeLauro (D-Conn.)

Goldman and Braden defended how they have handled the outbreak, saying it wasn’t until last week that they had accumulated enough evidence to link the outbreak to the Cargill plant. They noted that some of the cases have occurred among people with no history of consuming ground turkey or purchasing turkey that originated at the plant.

“There was an aggressive and thorough investigation that came together,” Goldman said.

Industry officials tried to reassure the public.

“The U.S. turkey supply has an excellent safety record,” said a statement from James H. Hodges, executive vice president of the American Meat Institute.

Officials emphasized that even contaminated ground turkey is safe to eat if it is cooked to 165 degrees. But raw meat must be handled properly before it is cooked, officials said. People should wash their hands with soap for at least 20 seconds before and after handling the meat. Turkey and other meats should also be properly refrigerated or frozen and leftovers heated.

The most common symptoms of salmonella are diarrhea, abdominal cramps and fever within eight to 72 hours of eating a contaminated product. It can be life-threatening to people with weakened immune systems.