As federal officials attempt to determine the source of a bacterium which killed a ten-day old newborn last week, several retailers have joined Wal-Mart in recalling a batch of powdered formula which the child consumed – and which the manufacturer assured Sunday is safe.

Retailers including Kroger, Safeway, Supervalu and Walgreen said Friday they have removed 12.5 ounce cans of Enfamil Newborn formula with the lot number ZP1K7G from their stores as federal officials investigate.

The manufacturer, Mead Johnson Nutrition, said Sunday it has retested the formula and said it can say “with confidence” that the product is safe, after not not detecting the presence of the Cronobacter bacterium.

The Glenview, Ill.-based company said the “highly unusual retesting” took place due to “continuing misinformation and confusion in the marketplace.” It says it tested samples similar to those being tested by public health officials, following the same methodology. It said it also gave shared its results with officials.

The Centers for Disease Control and Prevention and U.S. Food and Drug Administration are assisting into the probe.

Avery Cornett, of Lebanon, Missouri died last Sunday after contracting the infection. The parents said they had purchased the formula at a Wal-Mart in Lebanon, according to the L.A. Times.