A Murray mother and her young son have joined what is expected to be a growing number of people who are suing a California spinach producer blamed for a national E. coli outbreak that has caused spinach products to vanish from store shelves.

According to a lawsuit filed Monday in U.S. District Court against Natural Selection Foods LLC, Sheila Leafty claims she bought packages of spinach on several occasions last month. During that time, she fed her son, Brayden, spinach salads between Aug. 22 and Aug. 27. Leafty claims her son began suffering bouts of diarrhea on Aug. 29, and eventually he was hospitalized.

Brayden's illness is just one of an estimated 15 E. coli cases reported in Utah since the spinach-related outbreak was discovered. The FDA continues to recommend that consumers not eat any fresh, uncooked spinach.

Dr. David Acheson of the FDA's Center for Food Safety and Applied Nutrition said the number of people who have fallen ill from E. coli nationwide is 114, reflecting several new cases reported Monday. In addition to the 15 Utah cases, Wisconsin reported 32 cases and the one death attributed to the bacteria, Ohio 10, Indiana 8 and New York 7. Seventeen other states reported from one to six cases.

Federal officials on Monday began to test farms in California in the search for the source of the E. coli outbreak. While investigators have already conducted tests at the first processing company implicated in the outbreak, the source of the bacteria may be on farms in the Salinas Valley region of California, officials of the FDA said in a press conference Monday evening.

On Sunday, the FDA said that a second company in California has been implicated in the E. coli outbreak. The newly identified company, River Ranch Fresh Foods, obtained salad that included spinach from the first company implicated, Natural Selection Foods of San Juan Bautista, Calif. The spinach that passed through River Ranch was sold under the brand names Farmers Market, Hy-Vee, and Fresh and Easy.

The investigation is proceeding in what amounts to a rearview mirror, with state and local health officials receiving reports of illness, asking people what they ate and searching for the source. To identify the new company, officials examined Natural Selection's records and found it had supplied River Ranch.

Federal health officials told California farmers to improve produce safety in a pointed warning letter last November, nearly a year before the multi-state E. coli outbreak linked to spinach. In fact, the current food-poisoning episode is the 20th since 1995 linked to spinach or lettuce, FDA officials said.

While state and federal officials have traced the current outbreak to a California company's fresh spinach, they haven't pinpointed the sources of the bacteria. The regulatory agency does not consider the contamination deliberate.