Ecotin is a peculiar serine proteinase (enzyme) inhibitor protein isolated from E. coli decades ago. Its homologs were found in several pathogenic microbe species including the Pseudomonas aeruginosa (responsible for a vast of clinical infections) or the infamous Yersinia pestis (causative agent of the bubonic pleague (Black Death)).

Ecotin is capable of inhibiting enzmes with markedly different specificities and functions, including the three main pancreatic enzymes (bearing the protein digesting function in the mid gut) and many enzymes associated with immune response.

Many research groups have shown that ecotin is virulence factor of several pathogenic species: the microbes devoid of ecotin are incapable of establishing a population within the host.

One of my aims is to elucidate how the ecotin protects these microbes. So far, I have shown that one function of ecotin might be the inhibition of the complement system, a first line defense against invading pathogens. This novel finding sheds light on another function of ecotin, furthermore, some previous results (found in literature) may need re-interpretation in light of this result.