COLUMBIA, Mo. (AP) — Wal-Mart and health officials awaited tests Thursday on a batch of powdered infant formula that was removed from more than 3,000 stores nationwide after a Missouri newborn who consumed it died from a rare infection.

The bacteria in question occur naturally in the environment and in plants such as wheat and rice. But the most worrisome appearances have been in dried milk and powdered formula, which is why manufacturers routinely test for the pathogens.

Wal-Mart pulled the Enfamil Newborn formula from shelves as a precaution following the death of little Avery Cornett (pictured) in the southern Missouri town of Lebanon.

The government has not ordered a recall, and the manufacturer said tests showed the batch was negative for the bacteria before it was shipped. Additional tests were under way.

“We decided it was best to remove the product until we learn more,” Wal-Mart spokeswoman Dianna Gee said. “It could be returned to the shelves.”

Customers who bought formula in 12.5-ounce cans with the lot number ZP1K7G have the option of returning them for a refund or exchange, Gee said.

The product is not exclusive to Wal-Mart. The manufacturer, Mead Johnson Nutrition, did not immediately say how widely distributed the formula was among other stores.