July 5 (Bloomberg) -- The U.S. Food and Drug Administration is increasing its testing of foods and herbs traditionally used in Mexican cooking as it seeks the source of a salmonella outbreak that has hospitalized 130 people.

``We are not shutting down our borders'' to those products, said agency spokeswoman Stephanie Kwisnek today. ``We are stepping up our testing of products grown domestically and from Mexico.'' An earlier report by CNN said the U.S. would ban imports of some foods from Mexico.

Tomatoes initially were blamed on the outbreak that has stricken 943 people since April 10, according to statistics from the U.S. Centers for Disease Control and Prevention in Atlanta. More than a third of the cases have been reported in Texas.

In addition to tomatoes, jalapeno peppers, Serrano peppers and cilantro were added to the list of possible tainted products, Kwisnek said.

The strain, called salmonella saintpaul, takes two to three weeks to manifest itself, the CDC said. Those afflicted ranged in age from babies to 99 years old. The highest rate of illness has been among people in their 20s, and lowest among people 10 to 19 years old, as well as those 80 or older.

One man in his 60s who died in Texas from cancer had the infection, which may have contributed to his death, the CDC said.

To contact the reporter on this story: Nancy Kercheval in Washington at nkercheval@bloomberg.net.

Last Updated: July 5, 2008 16:42 EDT