Fungal Pathogensis
.... Endogenous infections, such as Canida albicans and Candida glabrata are normal flora of man. Subcutaneous infections are due to trauma or implantation of a foreign object. If they are disseminated, they can cause systemic disease. The redox potential of host differs. Most fungi are saprophytes. Enzymatic pathways function more efficiently at redox potential of dead substrates. There are also physiological barriers to fungal growth in humans. Most fungi growth is inhibited at 37 degrees Celsius. The host also has defense mechanisms. The main fungi cause disease primarily as an opportunistic pathogen. The fungi circumvent barriers by growing at 37 degrees Celsius by being thermally dimorphic or multi morphic. Also, change in growth at 37 degrees Celsius alters gene expression. The alternate form of fungi is associated with changes in enzymatic activity. The virulence factor of fungi has a variety of definitions. It ranges from the ability to grow at 37 degrees Celsius to the secretion of necrotizing toxin. The most common element is that the factors promote fungal colonization in hosts. The adherence to host is the ability of yeast or hypal cells to bind to host cells. Crytococcus neoformans produce a capsule that aids in resisting pathogens. Modulation of host community is also involved. Mechanisms that damage host are mycotoxins, mutagenic, carcinogenic or neurotoxic. Destructive enzymes make a phospholipose that produce a sheer growth of hypal forms. Crytococcus neoformans is an opportunistic and primary pathogen. t is acquired via inhalation. A ubiquitous organism is isolated predominately from soil or debris and then contaminated with bird droppings. Dehydrated blastopores are aerosolized. It utilizes catecholamines to deposit melanin in cell walls. Even if the cell dies, the melanin somehow manages to survive. Crytococcus neoformans is considered to be pathogenic when it is introduced into animals or man. It is melanized in soil and acquires a defens...