[21, 22] This leads to haematogenous dissemination of the organism to target organs, while ischaemic necrosis

of the infected tissue can prevent leucocyte and antifungal agent penetration to the foci of infection.[23] R. oryzae was used as a model system in understanding the basis of fungal pathogenicity. Sequencing the genome of a pathogenic R. oryzae strain there was evidence that the entire genome had been duplicated and retained two copies of three extremely sophisticated systems involved in energy generation and utilisation. This gene duplication has led to the development of gene families related to fungal virulence, fungal cell wall synthesis enzymes and signal transduction, which may contribute to the invasive nature of R. oryzae.[24] The important clinical observations that patients with diabetic ketoacidosis as well as patients receiving dialysis and selleck treated with iron chelator deferoxamine are characteristically susceptible to mucormycosis highlights the central role of host iron in the pathogenesis mTOR inhibitor of mucormycosis.[23] As proof of principle in vitro studies have shown that Rhizopus spp. can accumulate many-fold greater amounts of iron supplied by deferoxamine than A. fumigatus.[25] Deferoxamine per se is not the pathogenetic factor for infection but Rhizopus spp.

utilise deferoxamine as a siderophore to supply previously unavailable iron to the fungus.[26] However, not all Mucorales have the same susceptibility to iron chelators.[19] Host defences are modulated by a number of factors as evidenced from in vitro and preclinical data but only

from few case reports.[27] Such factors are cytokines and pharmacological agents including certain antifungal drugs. We will herein review relevant in vitro and in vivo studies and scant clinical data. An overview of immune response and its regulations against Mucorales is shown in Fig. 1. Adjunctive cytokine Selleck Lonafarnib treatment for patients with mucormycosis has long ago attracted scientific interest as a means to improve outcome through neutrophil recovery and restoration of host immune responses. Cytokines studied so far include the hematopoietic growth factors, granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF), as well as IFN-γ. These cytokines have been shown to stimulate proliferation and differentiation of myeloid progenitor cells to neutrophils (G-CSF, GM-CSF) or monocytes and eosinophils (GM-CSF), to up-regulate chemotaxis, phagocytosis and respiratory burst of phagocytic cells (neutrophils, monocytes, macrophages) (G-CSF, GM-CSF, IFN-γ) and to regulate/enhance protective T-helper type 1 (Th1) responses (IFN-γ).