As the number of confirmed cases of E. coli O26 linked to Chipotle restaurants increased to 52 in nine states, the company says it’s revamping its food-supply standards.

Chipotle will work with Seattle-based IEH Laboratories and Consulting Group, unveiled a new safety program that includes improving its supply chain and doing DNA testing of produce. Chipotle also is retooling its training to help employees handle food more carefully.

“While it is never possible to completely eliminate all risk, this program eliminates or mitigates risk to a level near zero, and will establish Chipotle as the industry leader in this area,” Mansour Samadpour, head of IEH Laboratories, said in a statement.

USA Today said Chipotle Mexican Grill will soon have stricter guidelines for its suppliers that will mean the chain will be using local produce less often.

Chris Arnold, a company spokesman, said in an e-mail Wednesday that the company plans on formally releasing some of its changes in the coming days, if not sooner.

“We do expect that some of the local suppliers we have used will not meet more stringent testing standards we have put in place,” Arnold said.