Medical Mycology PDF

M e d i c a l Mycology Dr. Noha Mostafa Assistant professor of Medical Microbiology and Immunology Faculty of Medicine Mansoura University  Eukaryotic Title and content layout with list Cell wall: Glucan,...

M e d i c a l Mycology Dr. Noha Mostafa Assistant professor of Medical Microbiology and Immunology Faculty of Medicine Mansoura University  Eukaryotic Title and content layout with list Cell wall: Glucan, Chitin Cell membrane: Sterol present Add your first bullet point here Yeast, Mold, Yeast like and dimorphic Add your second bulletReproduction: point here Sexual and asexual Add your third bullet point here Which of the following is (are) present in the fungal cell wall? a. Glycan b. Peptidoglycan c. Chitin d. a &c e. All of the above  Fungal Metabolism O2 1. Aerobic: All 2. Facultative anaerobes: Some Temperature: Optimum: 25 – 30 ºC (because most fungi are saprophytes which live in the environment) PH: wide range of pH (2 – 9), Generally they prefer acidic media  1. Yeast 2. Yeast-like Shape Unicellular ( rounded or oval ) Budding Budding Fungal classification (daughter remains attached Reproduction to mother  Yeast pseudohyphae) Cryptococcus Candida Example neoformans Dimorphic According to Yeast- fungi morphology like Moulds 3. Moulds (Filamentous fungi): Hyphae may be: septated or non-septated 1. Vegetative Hyphae: penetrate the media 2. Aerial Hyphae: grow above the surface of media & carry spores. 4. Dimorphic fungi: 2 forms: Yeast & Hyphae 1. Hyphae: occur at room temperature 2. Yeast: occur: a. On incubating culture at 37 ºC b. During infection in the body Example: Histoplasma capsulatum  Fungal reproduction A- Sexual reproduction: Involve the union of 2 nuclei or 2 sex cells or 2 sex organs.  B-Asexual reproduction: It is the main method of reproduction.  It includes: Fragmentation of hyphae & each fragment grows into a new individual fungus. Budding of cells, each bud produce new individual (e.g. Candida). Naming of mycosis  A. According to name of the organism: Candidiasis (= Candidiosis): Fungal infection by Candida. Aspergillosis: Fungal infection by Aspergillus. Cryptococcosis: Fungal infection by Cryptococcus. Histoplasmosis: Fungal infection by Histoplasma. B.According to the site of infection: Pulmonary mycosis: Fungal infection of the lung.  Types of human mycosis : 1.Superficial 2. Cutaneous 3. Subcutaneous 4. Systemic 5. Opportunistic Upper most Skin mucosal implantation of Multi organs occur in: horny layer of surfaces, hair spores into wounds affected Immuno- skin and nails compromized host M/T: Ex. ……………… 1. Inhalation of spores 2.Spread of local mycosis Tinea 1. Fungal flora versicolor Dermatophytes Mycetoma --Histoplasma (Candida) Candida 2. Saprophytic: fungi in the environment (Aspergillus) Diagnosis of fungal infections  1. Sample: According to the site of infection * skin, hair & nail samples. 2. Direct Microscopic Preparation: a) Unstained preparation: KOH (10 – 30%). b) Stained preparation: – Lactophenol cotton blue stain. 3. Culture for isolation of fungi: A. Characters: as in fungal metabolism B. Media: 1. Sabouraud`s dextrose agar (SDA) 2. SDA + Chloramphenicol + Cyclohexamide (Actidion) (0.5%) to inhibit saprophytic fungal contaminants growth 3. Blood agar: for fastidious dimorphic fungi SDA + Chloramphenicol + Cyclohexamide can be used to: a. Grow fungi and inhibit bacterial growth b. Grow bacteria and inhibit fungi c. Culture bacteria d. Grow both bacteria and fungi e. Non of the above 4. Woods light: Helps in clinical diagnosis. ultraviolet rays which when come in contact with mycotic areas of skin and hair produce fluorescent colours. 5. Indirect method of diagnosis: a) Serological diagnosis: ELISA. Candidal infection  Source of infection: Endogenous: (autoinfection): Present as normal flora in oral cavity, GIT, female genital tract and skin which is the major source of infection. Exogenous: By sexual intercourse.  Predisposing factors Extreme of age. Immunosuppression: Pregnancy and diabetes. Prolonged use of antibiotics, steroids or immunosuppressive drugs. Traumatic conditions such as catheter.  Causative agents: Candida albicans. Non-albicans Candida:  Clinical manifestations of diseases caused by Candida: A) Mucocutaneous infection: Oral thrush: Vaginitis: B)Cutaneous infections: Skin: Napkin area in baby. Nail: paronychia. Candida can cause which one of the following infections? a. Blood stream infection b. Urinary tract infection c. Mucocutaneous infection d. Endocarditis e. All of the above C)Systemic infections: Urinary tract infection. Endocarditis. Meningitis. Septicemia, fungemia. Laboratory diagnosis of Candidiasis: A. Direct: 1. Microscopic examination: –Unstained preparation (KOH) or stained preparation lactophenol- cotton blue stains. –For detection of yeast cells and pseudohyphae. 2. Culture: –On SDA medium.