Morphofunctional characterization and antibacterial activity of haemocytes from Octopus vulgaris.

In this study we have focused the attention on the morphological and functional characterization of the haemocytes from Octopus vulgaris as the first responsible of the innate immunity. Three major haemocytes types were identified by light microscopy based on nucleus/cytoplasm ratio and the presence or absence of cytoplasm granules: haemoblast-like cells, hyalinocytes and granulocytes. The presence of three haemocyte populations was also confirmed by flow cytometry. A cytochemical characterization shows their different activities responsible of the humoral response. Using plate radial diffusion method we demonstrated the bactericidal activity of haemocytes in the presence of different bacteria strains. In order to investigate the presence of soluble biotic compounds responsible of the antibacterial activity, using disc diffusion method and the minimum inhibitory concentration, we have also tested the methanolic acid extract from these cells. Our results pave the way for the development of potent antibacterial drugs that could lead to many applications.