Dormant bacteria within biofilms contribute to biofilm heterogeneity. Consequently, physiological
heterogeneity of biofilms may influence host immune response and tolerance to antibiotics. Recently, we
described an in vitro model to modulate dormancy in S. epidermidis biofilms. Here, we present a study based
on immunoproteomics, where we compared the reactive profile of S. epidermidis biofilm proteins with
prevented and induced dormancy, to human sera. A total of 19 immunoreactive proteins were identified by
MALDI-TOF/TOF. Most of these proteins present molecular functions, such as catalytic activity and ion
binding. CodY and GpmA proteins were more reactive to sera when biofilm dormancy was induced, while
FtnA and ClpP were more reactive when dormancy was prevented. This is the first work identifying protein
immunoreactivity differences between bacterial biofilms with induced or prevented dormancy. Considering
the importance of dormancy within biofilms, further studies on these proteins may provide insights into the
mechanisms related to dormancy and help improving current understanding on how dormancy affects the
host immune response
