Kroger has recalled its Basil Pesto Bowtie Salad and Smoked Mozzarella Penne Salad sold across several states in the US following a supplier alert over possible Listeria monocytogenes contamination.

The recall came as US authorities launched a wider investigation into a multistate Listeria monocytogenes outbreak linked to prepared meals.

The probe is being conducted by the Food & Drug Administration (FDA), the Department of Agriculture Food Safety and Inspection Service (USDA FSIS), and the Centers for Disease Control and Prevention (CDC).

Listeria monocytogenes can cause severe or fatal infections in young children, older adults, and individuals with weakened immune systems, and may lead to miscarriages or stillbirths in pregnant women.

During this outbreak, 20 infections have been reported across 15 states, resulting in 19 hospitalisations and four deaths.

One infection involved a pregnant woman and led to a foetal loss.

Fresh Creative Foods informed Kroger that the pasta used in the recalled salads may have been contaminated.

The pasta ingredient was produced by Nate’s Fine Foods in Roseville, California, which had earlier recalled certain lots of pre-cooked pasta, including fettuccine, linguine, and farfalle (bowtie), after a Listeria test returned positive.

Kroger received its first notice on 26 September about the affected bowtie pasta and a second alert on 1 October regarding penne pasta and additional production dates.

The affected items were sold in deli full-service and self-service sections at 1,860 stores under banners including Kroger, Baker’s, City Market, Dillons, Fred Meyer, Fry’s, Gerbes, King Soopers, Payless, Ralphs, and Smith’s.

The company has removed the products from sale and activated its customer recall notification system, which alerts buyers through receipts and email messages.

No illnesses or injuries directly linked to the recalled salads have been reported so far, according to Kroger.

Customers who purchased the recalled salads are advised not to consume them and to return the products to the store for a full refund or replacement.