Bacterial Evolution and Molecular Epidemiology

Maria Miragaia
Investigador Auxiliar
PhD in 2006 in Biology, UNL, ITQB

Phone (+351) 211157790
miragaia@itqb.unl.pt

Research Interests

Coagulase-negative staphylococci (CoNS) have a central role in the human skin flora, constituting one of the first barriers against pathogenic bacteria, such as S. aureus. Also, they are reservoirs of genes for other bacteria, and can cause disease. Hence, the study of CoNS and its interactions with other bacteria are crucial for the understanding of health and disease status. The research interests of the Laboratory of Bacterial Evolution and Molecular Epidemiology are centered on these three aspects of CoNS epidemiology: their role as human pathogens, as reservoirs and players in the evolution of antibiotic resistance and as modulators of colonization with pathogenic bacteria.
We have previously characterized the population structure of some clinically relevant CoNS species (Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus hominis). We are now devoted to identify genetic factors important for the pathogenicity in CoNS, frequently associated to disease.
The beta-lactam resistance determinant (mecA) originated from a native gene in the most primitive Staphylococcus species and is part of a mobile genetic element, SCCmec, but the steps in the evolution from a native gene into a mobile resistance determinant are unclear. One of our research projects focus on the study of the contribution of the different Staphylococcus species to the assembly and evolution of SCCmec.
CoNS species inhabiting the human skin probably act coordinately to protect against infection with pathogenic bacteria. We are interested in understanding the nature of bacterial interactions which contribute to homeostasis in CoNS ecological niches.