Functional Characterization of Ascorbate Peroxidase from Leishmania major

Abstract

Parasites are organisms that live on other living organisms (hosts), such as animals and plants. Infections of humans caused by parasites are numerous and range from relatively innocuous to fatal. Despite advances in modern medicine parasitic diseases still constitute major human health problems throughout the world and thus have made parasite research extremely challenging. Medical parasitology traditionally has included the study of three major groups of pathogens: parasitic protozoa, parasitic helminths (worms), and those of arthropods. Protozoan parasites are unicellular organisms that cause a wide variety of diseases like malaria, trypanosomiasis, toxoplasmosis and leishmaniasis. Since the parasites generally reside within the blood or internal organs of the host, they have logistical problems in terms of infecting a new host. To overcome this, vector transmission is the strategy used by protozoan parasites (Fig. 1). This strategy involves a hematophogous (i.e., blood feeding) arthropod serving as an intermediary between successive vertebrate hosts. Table 1 lists several human diseases that are caused by parasitic protozoa and the corresponding arthropod vectors that transmits them. Figure 1: Phlebotomine sandfly. Leishmania uses the sandfly as a vector