A nationwide investigation of all soft cheese products has been launched by the Food and Drug Administration as a result of a potentially deadly bacterial infection found in the Mexican-style soft cheese manufactured by a Los Angeles-area company, the agency said this week.

An FDA order, issued July 2, calls for samples to be taken "of various types of soft cheeses, not just Mexican-style cheeses," agency spokesman Emil Corwin said.

Because of the discovery of the contaminated cheese in California, Corwin said, "We want to get other information on other manufacturers of soft cheese."

He said the survey will examine products from a broad cross-section of soft-cheese producers in each state to make sure there are no signs of faulty pasteurization or of the bacteria Listeria monocytogenes. He said there is no evidence of a problem with other producers of soft cheeses, such as Brie and Camembert, or with cooking cheeses such as fresh ricotta, which are normally made with pasteurized milk.

The bacteria, linked to more than five dozen deaths nationally, were discovered last month in cheese produced by Jalisco Mexican Products Inc. of Artesia, Calif. The company, under criminal investigation by the Los Angeles County district attorney's office, closed last month and its products were recalled.

Richard M. Kennedy, director of the United Dairy Industry Association, representing some of the nation's largest dairy interests, welcomed the FDA's investigation.

"I think it's a warranted action," he said. "I think they want to make sure in their mind that all soft cheeses are 100 percent safe."

But another industry official, who declined to be identified, said he thought the FDA action "is overkill, given the fact that only Jalisco has thus far been implicated in causing illnesses or deaths.