Updated

U.S. federal health investigators have cleared an infant formula of suspected bacterial contamination that last week prompted retailers to pull a batch of the product from their shelves.

In a joint statement late Friday, the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) said tests of factory-sealed containers of the formula, made by Mead Johnson Nutrition Co., showed no contamination.

"Based on test results to date, there is no need for a recall of infant formula, and parents may continue to use powdered infant formula, following the manufacturer's directions on the printed label," the agencies said.

Earlier this week a baby tested positive for bacteria that killed a newborn in Missouri and prompted several major retailers to pull Mead's Enfamil Premium Newborn baby formula from their store shelves.

The infant from Oklahoma was recovering after testing positive for the Cronobacter sakazakii bacteria.

The baby's illness was the third Cronobacter-linked case in recent weeks, with another child from Illinois recovering after becoming sickened by the bacteria.

"CDC laboratory tests of samples provided by the Missouri Department of Health and Senior Services found Cronobacter bacteria in an opened container of infant formula, an opened bottle of nursery water and prepared infant formula. It is unclear how the contamination occurred," the agencies said of the tests conducted after the death of Missouri baby, Avery Cornett.

"The FDA has inspected the facilities that manufactured the infant formula and the nursery water that tested positive for Cronobacter bacteria. Those manufacturers have programs that test their products before they are distributed.

"The lots in question were tested and found negative for Cronobacter. There is currently no evidence to conclude that the infant formula or nursery water was contaminated during manufacturing or shipping."

Mead Johnson Nutrition Co., which produces Enfamil, said on Sunday that its own tests of its Enfamil Premium Newborn infant formula found no trace of the bacteria tied to the death of the Missouri baby.