(CNN) -- A farm linked to the recent outbreak of cyclospora has stopped sending lettuce to the United States, according to the Food and Drug Administration.
Taylor Farms de Mexico "voluntarily suspended production and shipment of any salad mix, leafy green, or salad mix components from its operations in Mexico," the FDA website says. The company says it will not sell these products again until it receives FDA approval.
As of Monday, 539 people in 19 states have been sickened by cyclospora, a rare type of parasite that causes intestinal illness, according to the Centers for Disease Control and Prevention. At least 32 people have been hospitalized.
The salad mix from Taylor Farms was linked specifically to cyclospora cases from Iowa and Nebraska. The CDC is not yet sure that all of the states' cases are part of the same outbreak.
FDA investigators traced the outbreak to four "illness clusters" of restaurants, which FDA spokeswoman Theresa Eisenman later identified to CNN as Red Lobster and Olive Garden locations. The probe didn't find indications that any bags of salad mix with the rare type of parasite were sold at U.S. grocery stores.
"Nothing we have seen prior to this announcement gave us any reason to be concerned about the products we've received from this supplier," the restaurants' parent company, Darden, said in a statement. Darden also insisted "it is completely safe to eat in our restaurants."
Taylor Farms has been cooperating with U.S. officials, the FDA said, adding that tests will be conducted at the company's processing facility in Mexico "to try to learn the probable cause of the outbreak and identify preventive controls." The last inspection there, in 2011, turned up no notable problems, according to the federal agency.
The company's CEO, Bruce Taylor, told CNN this month that its plant in Mexico produced and distributed about 48 million servings of salads to thousands of restaurants in the Midwest and Eastern United States in June.
"We have an extensive testing program in Mexico to test water sources and raw product for coliforms, E. coli, salmonella and listeria," Taylor said. "All our tests have been negative, and we have no evidence of cyclospora in our product."
As of Wednesday, there had been 153 cases of cyclospora inspections reported in Iowa, according to that state's public health department. There have been 86 reported cases in Nebraska. Texas currently has the most reported cases with 215, according to the CDC. Authorities have not singled out a common source for the Lone Star State's outbreak, which is largely centered in and around Dallas and Fort Worth.
Despite the lack of a connection, a Dallas woman sued Darden on Friday -- soon after the FDA implicated the restaurant company -- "for all general, special, incidental and consequential damages" tied to her July 1 visit to an Olive Garden in Addison, Texas.
Suzanne Matteis contends in her lawsuit that four days after eating spaghetti with meat sauce and a salad from Olive Garden, she suffered severe intestinal issues. She says a clinic near her home took a stool sample and diagnosed her with a cyclospora infection.
Matteis says she's still not feeling completely recovered. "I think I'm getting better, but I still don't have a lot of energy. I'm pooped. I'm worn out," she told CNN.
While he wasn't aware of the lawsuit until CNN alerted him, Darden spokesman Mike Bernstein said his group's restaurants in Texas have a different supplier than its restaurants in Iowa and Nebraska.
Iowa health authorities said last week that the prepackaged salad mix of iceberg and romaine lettuce, carrots and red cabbage was no longer in the state's supply chain.
"Bagged salads and all other vegetables are safe to eat," the state's health department said.
People get the disease by eating food or drinking water that's been contaminated with feces from the parasite. The ailment -- which strikes in places where cyclospora is common such as tropical or subtropical regions but occasionally in the United States as well -- causes symptoms such as diarrhea, weight loss and nausea that can last anywhere from a few days to more than a month.
CNN's Jacque Wilson, Val Willingham, Greg Botelho, Amanda Watts and Caleb Hellerman contributed to this report.