Fungal diseases Flashcards
Fungi
Fungi are chemotrophs and make use of saprophytic or parasitic mode of nutrition they secrete enzymes that break down a range of complex organic substrate into nutrients which they then absorb generally fungi a beneficial to humans and essential and recycling organic matter in the environment humans have is fungi for thousands of years in the production of food some fungi have been exploited in used in the production of antibiotics and other drugs as pathogens they have a significant influence on the agricultural industry with a result in which crop losses every year
Fungal species are spread over four phyla
Chytridiomycota
Zygomycota
Ascomycota
Basiodiomycota
The study of fungi is called___ and infections caused by fungi are called _____
Mycology
Mycoses
Fungi grow in two main forms
Unicellular yeast or multicellular moulds
Characteristics of fungi
Eukaryotic with at least one membrane-bound nucleus contain membrane-bound organelles similar to plant cells they possess a thick cell wall which in fungi takes the form of polysaccharide chains as well as Chitunn and glycoproteins
Infectious by pathogenic fungi can be classified as
Superficial mycoses
cutaneous mycoses subcutaneous mycoses systemic mycoses opportunistic mycoses
Diagnosis and treatment of fungal disease
Requires a combination of clinical observations and laboratory techniques in the laboratory specimens are generally studied by microscopic examination or culturing most my cases are difficult to treat as they are eukaryotes and many agents that are toxic to fungi also toxic to animals in this way they are and like bacteria which have very different gene products and biochemical pathways that can be targeted without resulting in toxicity to the host there are however a number of drugs that target fungi they are in perfect in that they often have severe side-effects and a narrow antifungal spectrum or poor penetration of human tissues the development of drug resistance is also
Candida
Form part of the normal skin gastrointestinal and mucous membrane flora
most candida species grow as yeasts and can form pseudohyphae
c albicans is dimorphic and can also form true hyphae on agar candida species form soft cream coloured colonies.
Superficial candida infections
Superficial cutaneous or muscle candidiasis can occur when there is damage to the skin or epithelium and the numbers of candida increase
Examples of superficial candida infections
Thrush
gastro intestinal candidiasis vulvovaginitis
Risk factors that contribute to the development of superficial mycoses
Diabetes reduced immunity treatment with antibiotics or corticosteroids and trauma
Systemic candida infections
Occurs when candida enter the bloodstream candida area is often nosocomial in origin and can be acquired from surgery or catheters in healthy individuals the infection is usually short-lived and the yeast is eliminated by the immune system
In immunocompromised individuals most serious illness may result in clothing
Kidney infections bone and joint infections skin lesions central nervous system candidiasis cardiac candidiasis disseminated candidiasis
