Mycology

Mycology is a small topic in microbiology where questions appears less in pg entrance but still we need to know it and learn about it in safe side... so here is a ppt with detailed explanation and images

1. MYCOLOGY -DR.AKIF A.B

2. Mnemonic : ZAB Z- Zygospores ( Phycomycetes ) A- Ascospores ( aspergillus ) B- Basidiospores (Cryptococcus) SEXUAL SPORES Ascospores Basidiospores

3. Methanamine silver BEST FUNGAL STAIN Mucicarmine stain and Alcian stain is used for Cryptococcus

4. Gomori methenamine silver stain - used to stain for fungi and for  Pneumocystis jiroveci ( carinii ) . The cell walls of these organisms are stained, so the organisms are outlined by the brown to black stain. There is a tendency for this stain to produce a lot of artefact from background staining, so it is essential to be sure of the morphology of the organism being sought.

5. GMS stain for Pneumocystis carinii

6. GMS stain for Coccidoides immitis .

7. GMS stain for  Cryptococcus neoformans

8. His = Histoplasma Pistol = Penicillium Shoots = Sporothrix Bullets & = Blastomyces Cartridge = Coccidiodes / Paracocci DIMORPHIC FUNGI - These can exist in 2 forms At 25* C = Mould At 37*C = Yeast - Sporothrix is Subcutaneous Dimorphic fungi whereas rest are systemic fungi

9. Gel immunodiffusion precipitin test Antigens are detected using specific antibodies - Detects mould form of dimorphic fungi EXO ANTIGEN TEST

10. YEAST LIKE FUNGUS Candida forms pseudohyphae apart from existing as Unicellular cells. Pseudohyphae

11. YEAST Cryptococcus Saccharomyces - Multiply by budding

12. clumps of intertwined branching hyphae M – Mucor A - Aspergillus R - Rhizopus D – Dermatophytes MOULDS: (MYCELIA)

13. MUCOR

14. RHIZOPUS

15. ASPERGILLUS

16. Fungi without identifiable sexual stage e.g : most medically important fungi DEUTEROMYCOTA (FUNGI IMPERFECTI)

17. Produced by fragmentation of hyphae . E.g : Coccidiodes , Paracoccidiodes ARTHROSPORES

18. MC media used for culture of fungi Antibiotics incorporated are : Cycloheximide , Chloramphenicol Gentamycin SABOURAUD’S DEXTROSE AGAR

19. Cutaneous T cell lymphoma MYCOSIS FUNGOIDES

20. C.neoformans : Soil with pigeon droppings C.gatti : Eucalyptus tree ( Gumtree ) CD4<200 MC cause of meningitis in HIV/AIDS Encapsulated budding yeast Causes Buschke disease MC form : Pulmonary Cryptococcus Confirmatory test : Latex agglutination test for polysaccharide antigen - Stains: 1) Mucicarmine stain 2) Alcian stain 3) Indian Ink stain : - ve stain i.e it stains background rather than organism - In HIV with CNS involvement : Induction : Amphotericin B +/- Flucytosine Maintenance : Fluconazole CRYPTOCOCCUS

21. The cytoplasm of the cells lining this are pink with the mucicarmine stain, indicative of mucin production. MUCICARMINE STAIN

22. INDIAN INK STAIN

23. Hortae ( Exophilia ) wernickii Painless, non scaly patches present on Palms and soles. TINEA NIGRA

24. White Piedra Black Piedra Trichosporon Beigelii ( Bhijli i.e current is white when sparks) Piedrae hortae Loosely attached to hair shaft (white hairs are loosely attached to scalp) Tightly attached to hair shaft Arthrospores Ascospores

25. - malassezia furfur ( Pityrosporum orbiculare ) Infects Stratum corneum Microscopy : Sphaggetti and meat ball appearance SDA culture : Fried egg appearance Wood lamps : Golden yellow fluorescence TINEA (PITYRIASIS) VERSICOLOR

26. TINEA (PITYRIASIS) VERSICOLOR

27. Microscopy : Sphaggetti and meat ball appearance TINEA (PITYRIASIS) VERSICOLOR

28. TINEA (PITYRIASIS) VERSICOLOR Wood lamps : Golden yellow fluorescence

29. DERMATOPHYTES - Tinea /Ringworm MC superficial mycosis MC type : Anthrophilic (Humans)

30. DERMATOPHYTES Microsporon Trichophyton Epidermophyton Infects Skin,Hair Skin,hair and Nail Skin, Nail Microconidia Rare Abundant absent Macroconidia Spindle shaped Pencil shape Club / clavate /paddle shaped

31. ZOOPHILIC DERMATOPHYTES T.equinum T.verrucosum M.canis M.equinum

32. TINEA CAPITIS - M.canis - T.tonsurans Seen on scalp Commonly in Children

33. Tinea corporis Tinea cruris Tinea pedis body ringworm Groin or jock itch athlete foot M.Canis T.mentagraphytes T.Rubrum T.Mentagraphytes E.floccosum T.Rubrum T.Mentagraphytes E.floccosum

34. TINEA PEDIS

35. TINEA CORPORIS

36. TINEA CRURIS

37. FAVUS -form of T.capitis -caused by T.schoenlenii

38. DERMATOPHYTID or ID REACTION -Hypersensitivity reaction to Dermatophyte antigens - Secondary lesion appears distal to primary lesion.

39. . MYCETOMA Eumycetoma Actinomycetoma Fungus –(40%) Bacteria – (60%) Single mass with well defined margins, Serous, black in colour , Osteosclerotic Multiple, ill defined margins, osteolytic,Purulet , White/Red Black granules : Madurella MC: Nocardia > Actinomadura madurae > Streptomyces : white granules White granules: Pseudoallescheria , Aspergillus fusarium Actinomadura pelletieri : Pink to Red granules Triad : Subcutaneous swelling + Discharging sinuses + Granules in sinuses Granules contains Silver Mycetoma - Histology Showing Splendore Hoeppli Phenomenon

40. MYCETOMA

41. MYCETOMA Mycetoma - Histology Showing Splendore Hoeppli Phenomenon

42. Similar to mycetoma but is caused by : Staphylococci Streptococci Pseudomonas E.coli BOTRYOMYCOSIS

43. Sclerotic / Medlar bodies (copper pennies) : Brown septate bodies forming pus Subcutaneous fungal infection - Darkly pigmented fungi CHROMOBLASTOMYCOSIS

44. MC in Tamil Nadu/A.P/KERELA/Orissa HPE : Polyp reveals spherules (Large sporangia containing numerous endospores ) MC site : Nasal cavity - Source : Stagnant water RHINOSPORIDIOSIS

45. MC fungal infection in Humans both in HIV & non HIV pt. MC :Candida albicans (Thick wall terminal chlamydospore on corn meal agar) Sugar assimilation/fermentation test : Used for species other than Candida albicans C.glabrata : Only species which doesn’t produce Pseudohyphae C.kefyr ( Pseudotropicalis ) :Used as standard strain for antifungal drug susceptibility testing CANDIDA Pseudohyphae

46. PSEUDOHYPHAE TRUE HYPHAE Constricted septa No constriction Origin of branch is constricted and septate No septum Grows by budding Atypical elongation

47. GERM TUBE TEST (REYNAULD’S BRAUDE PHENOMENON) - Differentiates hyphae with pseudohyphae - Serum at 37*C – True hyphae is formed CANDIDA

48. MC cause of Paranasal sinus mycosis MC form = Pulmonary aspergillosis : seen in prior lung disease Narrowed septate hyaline hyphae with long conidiophores with terminal vesicles Invades pulmonary cavities - Fungal balls In immunocompromised : Invades blood vessel – causes Thrombosis Treatment : Invasive aspergillosis : Voriconazole ABPA : Itraconazole Single aspergilloma : Surgery Chronic pulmonary aspergillosis : Itraconazole / Voriconazole ASPERGILLUS

49. A.FUMIGATUS - Pulmonary and allergic

50. A.FLAVUS Skin - Ocular infections Mnemonic : flame is seen by eyes and it burns skin

51. A.NIGER Otitis externa Mnemonic: Nigear : ear otitis

52. Caused by Rhizopus / Absidia / mucor Aseptate hyphae Sexual spores : Zygospores Asexually by : Sporangiospores MC form : Rhinocerebral mucormycosis ( Presnts as orbital cellulitis,Proptosis and vision loss) >Pulmonary mucormycosis - Vascular invasion is very common : Mucormycosis > Aspergillus - MC site of invasion ; Brain MUCORMYCOSIS/ ZYGOMYCOSIS/PHYCOMYCOSIS

53. MUCOR

54. Non cultivable fungus Environment : Cyst form Humans : Trophozoite and cyst form Methenamine silver : Cyst appears black coloured Pink pong balls against black background Best sample : Bronchoalveolar lavage Cyst inhaled – enters lung –FORMS TROPHOZOITES –Plasma cell infiltrates –Frothy exudates filling the alveoli B/L Perihilar exudates - Treatment ; Immunocompetent : Cotrimoxazole * 14days Immunocompromised : Cotrimoxazole * 21days PNEUMOCYSTIS CARINII

55. Methenamine silver : Cyst appears black coloured Pink pong balls against black background PNEUMOCYSTIS CARINII

56. Rose gardener’s disease Thorn of rose plant injury Painless nodulo -ulcerative lesion Spreads along Lymphatics R/F : Bare foot At 37*C : cigar shape asteroid bodies -25*C : MOULDS Best test : Culture Portal of entry : Skin - DOC : Itraconazole SPOROTHRIX cigar shape asteroid bodies

57. B - Blastomycosis P - Penicillium marnefii Cuff - Coccidiodomycosis Humerus - Histoplasmosis GRANULOMA FORMING FUNGI

58. Hyaline thin septate hyphae Conidia arranged in brush border appearance At 37*C : Yeast cells : Oval or elliptical with central septation - At 25*C : Brick red pigment mould PENICILLIUM MARNEFII Brush Border Appearance

59. Gilchrist disease North American blastomycosis HPE: Figure of 8 appearance (8-15MICRON) : B looks like 8 MC form :Pulmonary >skin Route : RespiratoryRoute Doesnt involve git DOC : Amphotericin B BLASTOMYCOSIS

60. Primarily infects Reticuloendothelial system 25*C : Tuberculate macronidia and thin micronidia 37*C : tiny oval yeast cell (2-4micron) with narrow based budding Intracellular single budding yeast cells in tissue Survives Within macrophage Reservoir : Soil with bat or chicken faeces HISTOPLASMOSIS

61. Valley/ California fever Inhalation of arthrospores causes disease MC form : Pulmonary Barrel shape arthrospores Mostly Seen in Desert areas. Hence k/a Desert Rheumatism - DOC : Itraconazole COCCIDIODOMYCOSIS Barrel shape arthrospores

62. -South American blastomycosis HPE : Mickey mouse appearance/ pilot wheel appearance Arthrospores DOC : Itraconazole PARACOCCIDIODOMYCOSIS

63. MC cause of Meningitis in AIDS : Cryptococcal MC cause of Seizure in AIDS pt. : Toxoplasmosis

64. ANTI FUNGAL DRUGS -DR.AKIF A.B

65. STRUCTURE OF FUNGUS -2 layered structure made of cell wall and cell membrane. Cell wall Cell membrane Made up of Chitins,Protein and beta glucans Ergosterol Contains beta glucan synthase that synthesise beta glucans for cell wall Squalene Levonosterol Ergosterol Squalene epoxide 14-Alpha sterol demethylase

66. STRUCTURE OF FUNGUS Amphotericin B Squalene Levonosterol Ergosterol Squalene epoxide 14-Alpha sterol demethylase Azoles Echinocandins Terbinafine

67. AMPHOTERICIN B - Amphipathic drug i.e it has both lipid and water soluble side -water soluble side binds with ergosterol and forms pore in fungus -Pores let water to accumulate inside cell and leads to lysis . - Poor oral absorption and hence given i.v along with 5%Dextrose as carrier . Amphotericin B

68. AMPHOTERICIN B DOC Systemic fungal infections Mucormycosis Kala azar Cryptococcal meningitis

69. AMPHOTERICIN B SIDE EFFECTS Nephrotoxic : To prevent patient is preloaded with 1-2L of Normal saline -To prevent nephrotoxicity Amphotericin is combined with liposomes,Lipid or colloid. 2) Hypokalemia 3) Hypomagnesemia 4) Anemia 5) Thrombocytopenia

70. FLUCYTOSINE It is a Prodrug of anticancer drug 5-FU It is given along with Amphotericin B for Induction therapy in Cryptococcal Meningitis It is given maximum for a duration of 2weeks because of risk of bone marrow suppresion and colitis

71. Treatment of Cryptococcal meningitis Induction : Amphotericin B + Flucytosine (Only for 2weeks) Maintenance : Azoles CRYPTOCOCCAL MENINGITIS

72. AZOLES -Inhibits synthesis of ergosterol by inhibiting 14 alpha sterol demethylase Fluconazole -DOC for Candidiasis and coccidiomeningitis Itraconazole -DOC for Endemic mycoses -Antifungal of choice for Allergic bronchopulmonary Aspergillosis Voriconazole -DOC for invasive Aspergillosis Ketoconazole -Inhibits Steroid synthesis and is hence used in Cushings Sx

73. Squalene Levonosterol Ergosterol Squalene epoxide 14-Alpha sterol demethylase Azoles AZOLES

74. AZOLES S/E DRUG SIDE EFFECTS Fluconazole - Hepatotoxic Itraconazole Hepatotoxic , CHF, Hypokalemia Voriconazole Hepatotoxic , QT prolongation Ketoconazole Anti androgenic action and causes Gynecomastia

75. ECHINOCANDINS Inhibits beta glucan synthase and hence breaks cell wall causing fungicidal effect -Poor oral absorption and hence given i.v . - Caspafungin - micafungin Echinocandins

76. TERBINAFINE - Inhibits ergosterol synthesis by inhibiting Squalene epoxidase Given orally and it accumulates in Skin, Nail and fats. Hence, It is DOC for Dermatophtosis . - S/E : Steven Johnson Sx and hepatotoxicity

77. Squalene Levonosterol Ergosterol Squalene epoxide 14-Alpha sterol demethylase TERBINAFINE

78. GRISEOFULVIN - S tabilises Microtubules of Fungi and hence has fungistatic effect Given orally and accumulates in S.corneum and hence is used in Dermatophytosis . DOC for treatment of Tinea Capitis in children S/E : Hepatotoxicity , Neutropenia , Neurological

79. TOPICAL ANTIFUNGALS B = Butenafine H = Halprogin U = Undencyclenic acid T = Terbinafine A =Azoles N = Nystatin , Naftifine

80. RECENT ADVANCES Isuvaconazole : Used for Mucormycosis and Aspergillosis Efinaconazole : used for Fungal toe nail infection