The effects of dopamine at physiological concentration on the growth and biofilm formation of Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli

Iron is an essential macronutrient for almost all living organisms, including pathogenic bacteria. Pathogenic bacteria have developed iron acquisition mechanisms due to the low bioavailability of iron inside the host. One of them is ability to utilize dopamine as a xenosiderophore. In this study we investigated the effects of dopamine at physiological concentrations (0.1–2 μM) on the growth and biofilm formation of bacteria grown in iron-limited and iron-enriched media. The significant growth enhancement was observed in Staphylococcus aureus USA300 grown in iron-enriched media. Dopamine at the concentration of 1 μM increased biofilm formation in S. aureus USA300, Staphylococcus epidermidis O47, and Escherichia coli K12 in both iron-limited and iron-enriched media after 3 days of incubation. These findings provide an insight into the effects of dopamine on bacteria at the physiological concentrations.