“I think the situation is we've got companies not paying attention to basic microbiology as it relates to listeria in these plants."

Listeria is a bacterium that can cause an illness called listeriosis when consumed by humans. It sickens about 1,600 people each year and kills about 260 people, according to the CDC.

Marler is representing the family of Shirlee Frey, who died in December of listeria found in tainted caramel apples, according to the wrongful death lawsuit he filed on their behalf. Although he said he has been contacted by the family of a Blue Bell listeria victim and several suspected Blue Bell listeria cases, he said it is unclear whether he will pursue legal action with any of them.

"I think all these [ice cream] companies are going to have to start thinking about it," he said of better testing.

Jeni's Splendid, which is based in Columbus, Ohio, was not immediately available for comment, but stressed in its recall announcement that the action was voluntary and no one had become ill.

"Our top priority is guaranteeing the safety of all consumers by taking every possible precaution," Jeni's CEO John Lowe said.

Sandra Eskin, a food safety expert at the Pew Charitable Trusts, said the Food and Drug Administration has a "zero tolerance" policy for listeria, but companies are not required to test for it.

The United States Geological Survey on Thursday released its first comprehensive assessment of the link between thousands of earthquakes and oil and gas operations, identifying and mapping 17 regions where quakes have occurred.

The report was the agency’s broadest statement yet on a danger that has grown along with the nation’s energy production.

By far the hardest-hit state, the report said, is Oklahoma, where earthquakes are hundreds of times more common than they were until a few years ago because of the disposal of wastewater left over from extracting fuels and from drilling wells by injecting water into the earth. But the report also mapped parts of eight other states, from Lake Erie to the Rocky Mountains, where that practice has caused quakes, and said most of them were at risk for more significant shaking in the future.