What is the most common bacterium responsible for mastitis associated with breastfeeding?

Staphylococcus aureus is indeed the most common bacterium associated with mastitis in breastfeeding women. This organism often colonizes the skin and can enter the breast tissue through cracks or fissures in the nipples, leading to infection. Mastitis typically presents with symptoms like breast tenderness, swelling, and sometimes fever, and it commonly affects women in the early weeks of breastfeeding.

Staphylococcus aureus is known for its ability to cause various infections and is particularly adept at forming abscesses, which can occur in cases of mastitis. Treatment usually involves antibiotics, and when necessary, drainage of any formed abscesses.

In contrast, other bacteria such as Listeria monocytogenes, Escherichia coli, and Streptococcus pyogenes are not commonly implicated in breastfeeding mastitis. Listeria is more associated with foodborne illness and can affect pregnant women but is not a typical cause of mastitis. Escherichia coli is primarily a gut bacterium and less so in skin-related infections. Streptococcus pyogenes can cause infections but is less frequently implicated than Staphylococcus in this particular context.