NEWTON, Mass. -- Hold the tomatoes. Signs posted at franchises in Newton and around the country advise customers that the fast-food outlet has temporarily removed sliced tomatoes from its menu, after a Food and Drug Administration advisory warned of a salmonella outbreak.

The sign read that McDonald's "hasn't experienced any related negative issues to date, but consider this a precautionary measure."

NewsCenter 5's Jorge Quiroga reported Burger King and Taco Bell have also stopped serving sliced tomatoes.

Salmonella food poisoning first linked to uncooked tomatoes has spread to 16 states, federal health officials said.

McDonald's has removed tomatoes from its sandwiches. Spokeswoman Danya Proud said McDonald's will continue to serve grape tomatoes in its salads because no problems have been linked to that variety.

The source of the tomatoes responsible has not been pinpointed. The illnesses began between April 16 and May 27, Arleen Porcell, a Centers for Disease Control spokeswoman said.

The U.S. Food and Drug Administration warning covers only certain varieties of tomatoes, including Red Plum, Red Roma and Round Red Tomatoes. Cherry and grape tomatoes and tomatoes with the vine still attached are considered safe.

To be absolutely safe, this produce market suggests plum tomatoes should only be used cooked. Many other varieties come from FDA-approved regions.

Salmonella can cause serious and sometimes fatal infections, particularly in young children, sick and elderly people.

"It's hot out. Salmonella is going to dehydrate people, especially the elderly and the young," said Max Petersen of West on Centre restaurant.

"The tomatoes in question are mainly used for commercial use in restaurants, for institutional trade, hospitals and schools," said Tony Russo of Russo's Market.

About 150 people have been sickened by the salmonella "Saintpaul" infection in Arizona, California, Colorado, Connecticut, Idaho, Illinois, Indiana, Kansas, New Mexico, Oklahoma, Oregon, Texas, Utah, Virginia, Washington and Wisconsin, the CDC reported.

Common symptoms include fever, diarrhea, nausea, vomiting and abdominal pain.

The state Department of Public Health said there have been no cases of salmonella linked to tomatoes identified in Massachusetts.

The DPH said it would notify distributors, retailers and boards of health of any updates associated with the outbreak as the FDA provides new information.