ABSTRACT
This chapter is concerned with deep fungal infections. Fungi generally reproduce asexually by mitotic spore formation. They exist as yeasts or molds. The dimorphic fungi are yeast-like in tissue, hyphal on artificial media and in the proper natural environment. Those fungi producing invasive destructive disease of deeper body structures are called the "deep fungi"; their diseases, "systemic mycoses". The deep fungi are distinguished from the superficial fungi, which produce trivial or annoying but not life-threatening epidermal infections. The cell wall of fungi is composed of polysaccharides and chitin. Cryptococcus neoformans also contains an outer polysaccharide capsule. Aspergillus species are ubiquitous microorganisms which cause invasive disease primarily in immunosuppressed patients. Species of candida are normal inhabitants of the skin and mucous membranes. Cryptococcus neoformans is widely encountered in the environment and probably commonly produces infection. Paracoccidioides brasiliensis causes a granulomatous disease of skin, mucous membranes, lungs, and reticuloendothelial tissue.
