Mycology revision notes
18 likes4,325 views
The document provides an extensive overview of mycology, detailing fungal characteristics, culturing methods, staining techniques, and classification of fungi based on morphology and reproduction. It discusses various fungal infections, including superficial, subcutaneous, and systemic mycoses, as well as the causative organisms and appropriate treatment options. The document also covers specific conditions such as dermatophytosis, tinea, and sporotrichosis, along with relevant laboratory diagnosis methods.
Mycology revision notes
- 1. Mycology
- 2. Fungi • Non motile eukaryotic • Lack chlorophyll /don’t require aerobic environment • Rigid cell wall made of chitin (polymer of N – acetyl glucosamine ) mannan & polysaccharides
- 5. Culture • Sabarouds dextrose agar • Czapek dox media • Corn seed agar
- 6. Culture • Cultured in Sabourauds agar • rhizopus / rhinosporidium cannot be cultivated • Malasseziz furfur difficult to cultivate
- 7. Sabouraud’s Dextrose Agar • Most common medium used for culture of fungi is Sabouraud’s Dextrose Agar • (Antibiotics incorporated are Cycloheximide, Chloramphenicol, Gentamicin); pH = 6.8 to 7.0. • Other media commonly used for growing fungi are yeast extract phosphate agar and BHI agar to demonstrate yeast form at 37 * c, Potato dextrose agar, corn meal agar, blood agar.
- 8. STAINING USED FOR FUNGI • KOH wet mount preparation • Gram staining for candida gram positive • Calcoflour white • Methenamine silver stain • PAS • Lactophenol cotton blue
- 13. • Gomori’s methenamine silver stain is the best fungal stain. It only stains fungi. • Mucicarmine and Alcian stain are used to stain the capsule of Cryptococcus neoformans in tissues.
- 15. • Masson Fontana stains melanin brown in fungal cell walls. • Gomori methanamine silver stains all fungal cell walls brownish black and is the most sensitive stain for fungal cell walls. • H&E stains some fungal cells purple. • Mayer’s mucicarmine stains cryptococcal cells burgundy red. • PAS stains all fungal cell walls red. PAS also stains some microsporidia, Tropheryma whipplei, and many polysaccharide containing structures within the tissue
- 17. Morphological classification • Yeasts • Yeast like • Molds • Dimorphic fungi
- 18. Yeast • Reproduce asexually by budding or fission • Round or oval unicellular algae • Form moist or mucoid colonies • Eg : Cryptococcus neoformans / saccharomyces cerevisiae
- 20. Yeast like • Formation of pseudohyphae (chains of elongated cells having constriction at the septa) • Eg : candida albicans
- 21. Molds • Produce branching filaments called hyphae • Septate or • Aspergillus /pencillium/fusarium/malssezia • aseptate (coenocytic) • Mucor /rhizopus & other fungi • Tangled mass of hyaphae mycelium • Part of mycelium above culture medium aerial • Part of mycelium below culture medium vegetative • Aspergillus/pencillium/ mucor /dematophytes
- 23. Dimorphic fungi • Yeast form in body and in culture media at 37 *c • Mold form in vitro at 25 * c • Histoplasma,blastomyces Sporothrix, coccidiodes, paracoccidiodes, pencillium marneffi • His blasted sports car party pen Most fungi causing sytemic infectionsdimorphic
- 27. Classification of spore Sexual spore • Zygospore • Ascospore • Basidiospore Asexual spore • Blastospore • Budding yeast cell , candida sps • Arthrospore • Mold form of • Chlamydospore • Candida albicans • Sporangiospores • rhizopus mucor • Microconidia • Single celled • Macroconidia • Multicellular • microsporum
- 28. Sexual spores formed by meosis • Zygospore • By conjugation of 2 fungi • Ascospore • In sac like structure called ascus • Basidiospore • Sexual spores formed on basidium
- 29. Asexual spores formed by budding fission or mitosis • Blastospore • As a result of Budding yeast cell , candida sps • Arthrospore • Fragmentation of hyphae • Mold form of Coccidioides, Paracoccidioides • Chlamydospore • Large with double refractile wall produced from hyphal cell • Candida albicans • Sporangiospores • Asexual sporesformed inside sporangium • rhizopus mucor • Conidia produced exogenously on hyphae Microconidia Single celled Macroconidia Multicellular microsporum
- 31. Systemic classification of fungi • Phycomycetes • Nonseptate hyphae and form endogenous asexual spores (sporangiospores ) contained with in swollen sac called sporangia • Also produces sexual spores (oospores ) in some and zygospores in some • Ascomycetes • Ascospores • Basidiomycets • basidiospores • Detromycets or fungi imperfecta • Sexual phase not identified • All most al fungi of medical importance
- 32. Anamorph • Imperfect/ asexual stage of fungi Telomorph • Perfect / sexual stage of fungi
- 33. Fungal infections • Superficial mycoses • Subcutaneous mycoses • Systemic mycoses • Opportunistic mycoses • Miscellaneous • Otomycosis / keratomycosis
- 34. Superficial mycoses • Dermatophytosis • Infection of skin ,hair & nails • Piedra • Tinea nigra
- 35. Piedra • Fungal infection of hair • With firm irregular nodules along hair shaft • Trichophyton nodes on hair • May be • Black piedrae hortae • White trichospron
- 36. Black piedra piedaia hortae • Discrete black gritty hard nodules on hair of scalp • 10% KOH • Of crushed nodule • Dark septate hyphae with club shaped asci each containing 2-8 ascospores • Unique among pathogenic fungi as it produces spores in parasitic phase
- 37. White piedratrichosporon beigelii • Soft mucilaginous grayish nodules on hair of genital area/ beard /moustache • Hair breaks at the point of infection laving distal end swollen • 10% KOH • Mycelia which break in to arthrospores
- 38. Tinea nigra • Hortaea wernecki (exophiala wernecki ) • pigment producing fungus • 10% KOH • Septate branching hyphae and budding yeast cels • In SDA dark pigmented colonies • Asymptomatic brown or black patch on palms and soles • Rx • Keratolytics • 2% salicylic acid
- 40. Dermatophytosis • Superficial fungal infn of keratinised tissue (skin ,hair and nails) • 3 genera based on macroconidia • Trichophyton ( skin + hair + nails) all three • Microsporum (hair and skin) • Epidermophyton (skin + nails)
- 42. trichophyton
- 43. Microsporum
- 44. Epidermophyton
- 45. • Macroscopically, the colonies of Epidermophyton have a yellowish appearance (KHAKI Colored Growth). • This dermatophyte invades skin and nails but never hair. On microscopic examination, clavate or paddle-shaped macroconidia are evident, with rounded ends and smooth walls. Microconidia are absent.
- 48. In lesions •Form hyphae & •Arthrospores In culture •Form sepate hyphae •Asexual rproductive structure micro & macroconidia
- 51. Dermatophytoses Common causative organism Tinea capitis Microsporum Trichophyton most species Favus T schoenlenii T violaceum M gypseum Tinea barbae T rubrum T mentagrophytes T veruccosum Tinea imbricate T concentricum Tinea crura E flocossum T rubrum T pedis T rubrum E floccosum Ectothrix hair Microsproum sps T rubrum MTr Endothrix T violaceum T tonsurans T shoenleni (TVS)
- 53. Tinea pedis /athlete’s foot • MC type of tinea • MC cause is T.rubrum • Indterdigital type and involves the 4th web space MC • Mocassin type involves the soles
- 54. Tinea capitis • Hair and scalp easily pluckable hairs • caused by T. tonsurans ( in usa ), t.violaceum (IN INDIA) ,microsporum canis • Bright green colour on woods lamp • Rx • Griesofulvin
- 55. • M. canis is a dermatophyte that infects skin and hair but rarely nails. When hair is infected with this organism, it will fluoresce. Microscopic examination of this organism demonstrates rough-walled macroconidia of 8 to 15 cells
- 56. • Non inflammatory • 1). Scaly grey patch (ectothrix), itchy area of alopecia, single or multiple patches • Arthroconidia appears appears as sheath on the surface • Microsporum canis • 2). Black dot (endothrix) variety - caused by T. violaceum, T.tonsurans • Arthrospore formn occur with in shaft
- 57. • Inflammatory • 1). Kerion (boggy swelling) caused by T. mentagrophytes, M.canis • Boggy swelling of scalp • Multiple sinuses discharging pus • Easily pluckable hair • Rx greisofulvin • 2). Favus - caused by T. Schoenleinii • In kasmir • With scutulus (dense crust)
- 58. Tinea corporis • Affects glabrous or non hairy skin • All dermatophytes (E,M & T) tinea corporis • Mainly T. rubrum • Central clearing Central clearing: Tinea corporis Central crusting: Leishmaniasis
- 59. Tinea cruris • Dhobi’s itch / jock itch • Infection of perineum, groin, perianal area, pubic area • Mainly T. rubrum
- 60. Tinea manuum • Scaling in creases • T. rubrum is the main cause
- 61. Tinea unguium • Infection of nail plate or nail bed by T. rubrum • Distal end onycholysis , • Sub ungal tan crumbly debris • Subungal hyperkeratosis • Bownish discolouration due to colonisation by aspergillosis • Rx • Itraconazole and terbinafine
- 62. Tinea imbricate • T concentricum • Related to steroid use • Concentric lesion
- 64. Pityriasis versicolour /tinea versicolour Pityriasis means scaling Most common type of superficial mycosis • Caused by malassezia furfur (hyphal form) and malssezia globose • Yeast form pityriasis orbiculare • Groups of macules which are hyperpigmented in whites / hypopigmented in dark skinned races, are seen over chest ,shoulder and back light brown macules with furfuraceous (rice powder) scaling
- 65. Pityriasis versicolor • c/c superficial infn of stratum corneum • White to brown colured lesions covered with scales • Caused by lipophilic fungus malassezia furfur • Tinea versicolor (pityriasis versicolor) is not a dermatomycotic condition but, rather, a superficial mycosis now thought to be caused by M. furfur. The disorder is characterized by chronic but asymptomatic scaling on the trunk, arms, or other parts of the body.
- 66. chest ,shoulder and back light brown macules with furfuraceous (rice powder) scaling
- 67. Pityriasis versicolor • coup d'ongle sign • Stroke of nailloosening of scales • Yellow / golden fluorescence under wood's lamp • KOH smear show characteristic • "Sphaghetti & Meatball" appearance • Cigar butt hyphae • Round spores
- 68. Lab diagnosis of PV • Direct examination • 10% KOH mount preparations • Budding yeast cells + short curved hyphae (banana & grapes / spaghetti & meatball appearance) • Culture • SDA with olive oil (lipophilic fungi ) • Yield creamy colonies in 5-7 days
- 69. "Sphaghetti & Meatball" appearance
- 70. • Treatment of Tinea versicolor • a. Systemic azoles (ketoconazole 400mg stat, fluconazole 400 mg stat or itraconazole 200 mg daily for 5 days ) provide a convenient therapeutic option. • b. Topical antifungals are also effective; • Azoles (clotrimazole, econazole, miconazole, ketoconazole shampoo ), • selenium sulphide 2.5% • sodium thiosulfate, • Whitefield’s ointment (3% salicylic acid + 6% Benzoic acid)
- 71. Tinea incognito • Extensive ringworm with an atypical appearance d/t inappropriate use of topical corticosteroids
- 72. id reaction • Allergic reaction to circulating dermatophytes Ag • Released by dying fungi during antifungal Rx • Characterised by skin vesicle formation distant from primary site • Sterile vesicle
- 76. Subcutaneous mycoses • Mycetoma • c/c granulomatous infection • Infection following traumatic inoculation • Triad of symptoms • Tumefaction of affected tissue • Draining sinus tracts • Grains or sulphur granules (microcolonies of fungi)
- 77. mycetoma • 3 types • Eumycetoma (more prevalent in N india ) • Madurella mycetomatis causes eumycetoma, as it is a fungus. • Actinomycetoma (in s india ) • actinomycetes of the genera Nocardia, Nocardiopsis, Streptomyces, and Actinomadura • Botryomycosis • Botryomycosis is similar to mycetoma but is caused by bacteria like Staphylococcus, Streptococci, Pseudomonas and Escherichia colli. • Actinomadura madurae,>>> second most common cause is Madurella mycetomatis.
- 79. Thin filament <1um Broader 4-5um Treated by sulphonamides Treated by amputation
- 82. Mycetoma /Madurai foot • First described in Madurai • c/c course Painless massive swelling with intermittent discharge of pus • In farmers • Pain d /t secondary bacterial invasion or bone invasion
- 83. Lab studies • Direct microscopy • Of serosanguinous discharge • Actinomycotic granules • Very finr filaments • Fungal grains • Short hyphae / branched filaments • DNA sequencing • X ray • Multiole lytic lesions or cavities • Cortical thinning d/t compression from outside • Osteoporosis in severe cases
- 84. • MRI • Soft tissue & bone invasion • DOT IN CIRCLE SIGN in soft tissue in MRI
- 88. Eumycetoma produces black or white granules
- 90. • Rx • Actinomycetomas respond to rx better than eumycetoma • Eumycetoma is resistant amputation • Rx for 1-2 years • Trimethoprim –sulfamethoxazole • Dapsone • Amikacin • Minocycline • Rifmpicin in reistant cases
- 93. Sporotrichosis aka rose gardeners ds • Occupational hazard in rose gardeners • caused by sporothrix schenckii (dimorphic fungi) • The organism often is found on thorns of rosebushes. • lymphocutaneous sporotrichosis, • Commonest • begins at the site of inoculation, usually on an extremity or the face. • Ulceration is common, and new lesions appear along paths of lymphatic channels. • Fixed cutaneous /mucocutaneous /disseminated/pulmonary • primarily in bones and joints. • There is no evidence to suggest that any portal of entry besides skin is important
- 94. Cigar shaped yeast form in sporothrix
- 97. Lab diagnosis • Sporotrichosis is characterized by cigar shaped budding cells by eosinophilic spicules, called asteroid bodies.
- 98. Splendore-Hoeppli Sporotrichosis • Splendore-Hoeppli or Asteroid phenomenon: • Abscess containing brightly eosinophilic, pseudomycotic structures composed of necrotic debris and immunoglobulin in starburst pattern • central basophilic yeast cell with eosinophilic (immune complex deposition) material radiating from it
- 99. • Culture • Flower like / rosette pattern of conidiophores • Rx • Cutaneous • KI • ITRACONAZOLE
- 100. Chromoblastomycosis • Mc form of chromomycosis • c/c localized infection of skin and sc tissue • Irregular rough cauliflower like lesions involving lower leg & feet • Caused by phaeoid (dematiaceous fungi)/pigmented • Fonsecaea pedrosol (mc) • Cladosporium carrionii (mc) • Phialophora veruccosa • Rhinocladiella aquaspersa • following the traumatic implantation of these fungi • Present as sclerotic bodies in lesion • aka Copper pennies bodies/ medlar bodies • Dark brown subglobose multicellular structure sclerotic bodies
- 103. sclerotic bodies (also called as copper penny, Medlar bodies & muriform cells) • Sclerotic bodies are planate dividing yeast cells. • Dark brown subglobose multicellular structure
- 104. • Lab diagnosis • Muriform bodies are characteristic tissue form of all causative organism • Fontana masson • Dematiaceous nature of fungi
- 105. • Rx • Liquid N2 therapy laser/heat photocoagulation • Amhotericin B thiobendazole 5 Flu orocytosine
- 107. phaeohyphomycosis • Fungus in the tissue is present in the form of darkly pigmented septate hyphae nd not as thick walled cluster of cells allergic fungal sinusitis • Commonly caused by exogenous dematiaceous fungi • Wangiella • Exophiala
- 110. Rhinosporidiosis • c/c granulomatous d/s of mucus memb • Bleeds on touch • nasal cavity • Conjunctiva • Rhinosporidium seeberi • Pedunculated nasal masses • obstruction • foul odor • epistaxis • young males of India
- 111. Sporangiaendospore
- 112. • Rx • Surgical excision • Dapsone for recurrence
- 113. Systemic mycoses
- 114. Histoplasmosis / darlings ds • Dimorphic fungus Histoplasma capsulatum • Grows in soil enriched with N2 • Excreta of bats & birds • Common in Africa & America • Infects RE system • Intracellular unicellular org in macrophages • infectious form microconidia • By inhalation • Multiplies inside alveolar macrophages
- 115. Intracellular unicellular org in macrophages
- 116. Inhalation of spores
- 117. Dimorfic fungi Histoplasma capsulatum • Misnomer not encapsulated • Cf • Asymptomatic • Clinical types • a/c pulmonary or c/c pulmonary • Cutaneous / subcutaneous/ mucocutaneous / disseminated
- 118. Histoplasma causes military calcification
- 119. • Biopsy of bone marrow /cutaneous or mucosal lesions • Geimsa/wright/ calcoflour white • Intracellular budding yeast cells intracellular macrophages • Culture • SDA at 25 *c • Septate branching hyphae with 2 types of asexual spores • Large tuberculate macroconidia • Smooth walled microconidia • Brain heart infusion at 37 * c yeast form • Histoplasmin skin test
- 120. Blastomycosis • Gilchrists ds / chicagos ds common in north America • North American blastomycosis • Dimorphic fungus blastomyces dermatidis • Natural habitat soil • Infn is due to inhalation of spores • CF • Cutaneous • Pulmonary / disseminated
- 121. Pyogranulomatous systemic fungal infection of lungs disseminated to extra pulmonary sites like skin bones & genitourinary system
- 122. Lab diagnosis • Pus from abscess sputum tissue • Direct microscopic examination • Methenamine silver /H & E staining • Thick walled spherical yeast cells • Single bud with broad base of attachement • On PAS staining • Splendore hoepelli phenomenon
- 123. • Culture • SDA @ 25 *C • Septate branching hyphae with smooth walled spherical or pyriform microconidia on short terminal branch • Brain heart infusion at 37 * c yeast form • Blastomycin skin test
- 124. DOC in blastomycosis • Amphotericin B
- 125. PARACOCCIDIOIDOMYCOSIS • South American blstomycosis / lutz mycosis • Dimorphic fungus Paracoccidioides brasiliensis • Due to inhalation of spores • CF • Acute / subacute (juvenile) • Chronic (adult) • Primary pulmonary infection that spreads haematogenously to mucosa of nose , mouth GI tract , skin lymphatics c/c granulomatous reaction
- 126. Lab diagnosis • Specimen • Pus from abscess /sputum/ biopsy from lesions • Direct microscopic exmn • Yeast cell with multiple buds ( mariners wheel /mickey mouse appearance/pilot wheel appearance)
- 127. • Culture • SDA @ 25 *C • Septate branching hyphae with chlamydospores /microconidia and arthrospores • Brain heart infusion at 37 * c yeast form • paracoccidioidomysin skin test
- 129. Coccidiodomycosis • Dimorphic fungus coccidiodes immitis • Inhalation of arthroconidia • CF • Primary pulmonary type • Influenza like illness • females develop delayed type hypersensitivity reaction reaction after 1- 2 weeks san joaquin valley fever /desert rheumatism • Primary cutaneous /scrofuloderma type • Enlargement of cervical LN • Disseminated type (osteoarticular lesions/CNS involvement)
- 132. • Specimen • Pus frm abcess sputum • DOUBLY REFRACTILE THICK WALLED SPHERULE CONTAINING ENDOSPORES • Culture • SDA @ 25 *C • Septate branching hyphae with chlamydospores /microconidia and arthrospores • yeast form DIFFICULT TO BE ACHIEVED • coccidioidomysin skin test
- 133. • . C. immitis is a dimorphic fungus endemic in some regions of the south western United States and in Latin America. • In tissue, the organism exists as a spherule filled with endospores. • When grown on solid media, the organism produces barrel-shaped arthroconidia, which stain with lactophenol cotton blue..
- 135. • CANDIDA YEAST LIKE FUNGUS
- 136. Candidiasis • Commonest mycoses involving skin & its appendages ,mucosa and internal organs • Mc fungal infection in immunocompetent host • Caused by yeast like fungus candida albicans (80-90%) • Germ tube positive • Occur as normal flora of skin/mucusmemb/GIT endogenous infection • Predisposing factors • DM HIV neutropenia malignancy
- 137. • CF • Mucocutaneous • oral thrush >>>Vulvovaginitis/ /esophagitis /balanitis/conjunctivitis/keraritis • Skin & nail infection • Intertriginous areas • Skin axilla sub-mammary folds • Systemic • UTI/ pulmonary /meningitis/ endocarditis
- 139. • While C. albicans is most commonly isolated, other species such as C. tropicalis and Torulopsis glabrata are also seen. • The yeasts may be identified biochemically, but C. albicans is distinctive in that it produces germ tubes and chlamydospores.
- 140. Reynold Braude phenomenon • Germ tube formation is seen • C. albicans • C. tropicalis. • C. dubliniensis. • If a few colonies of Candida albicans are inoculated in serum, the yeast cells start to form elongations called germ tubes within 2 hours, when kept at 37C.
- 141. Enzymes by candida help in pathogenesis • Secrete aspartyl proteinase • Phospholipase @ tip help in inasiveness
- 142. • Candida Gram positive • Budding yeast cells • Pseudohyphae
- 143. • Terminal Chlamydospore on corn meal agar
- 144. • Grow well on blood agar & SDA 25 * c – 37 *c
- 145. • Rx • Cutaneous • Topical ketoconazole /miconazole • Nystatin • Systemic • Amphotericin B • Fluconazole • Itraconazole
- 146. • C. dubliniensis. • Seen in HIV patients • Resistance to fluconazole • Dark green on chrome agar • Germ tube +
- 147. Cryptococcus • Cryptococcus neoformans • Encapsulated • Prominent polysaccharide capsule • Capsular halo india ink preparn • Antiphagocytic and poorly immunogenic • true yeast • ONLY PATHOGENIC YEAST • Multiply by budding Blastospore + • 5 serotypes A, B ,C ,D , • Infn acquired through inhalation of yeast cells • From pigeon droppings A & D • FROM EUCALYPTUS TREE B • From lungs yeast can metastases to any organ of body
- 148. Cryptococcus • Urease + • Based on biochemical properties 3 varieties • C. neofromans var neofromans (D) • In pigeon droppings • C. neofromans var gatti (B,C) • In eucalyptus trees • C. neofromans var gubrii (D) • In pigeon droppings
- 149. • Cryptococcosis • European blastomycosis • TORULOSIS • Most common SYSYTEMIC or invasive fungal ds in HIV infected person (CD4<200)
- 150. • Pulmonary • CNS meningitis (MC) • Intracranial space occupying lesion cryptococcoma • In basal ganglia / head of caudate nucleus • Cutaneous(molluscum like lesion) / osseous/visceral
- 152. Lab diagnosis • Specimen CSF or tissue specimens • To demonstrate capsule Negative staining • NIGROSIN / india ink • Culture • SDA • bird seed agar (STAIBS MEDIUM) • Antigen detection • CRAg cryptococcal Ag detection test in blood & CSF
- 153. Cryptococcus • Rx • AMB • Flucytosine • Fluconazole aintenance therapy
- 154. Aspergillus • 4 species • A fumigatus (commonest cause of invasive aspergillosis) seen in DM • A niger • A terries only invasive ds • A flavus YELLOW COLOUR AFLATOXIN • Infn acquired by inhalation of mycelia or conidia • Predisposing factors • Immunosuppresion • Neutropenia • Bone marrow transplantation • AIDS
- 155. Aspergillus • Acute /narrow angle septa (45*) • Septate hyphae • Septate hyphae with a/c angle branching • Penetrate vessels • Eosinophilia • fRuting bodies with conidia
- 156. • A fumigatus (commonest) • Invasive aspergillosis • Pulmonary aspergillosis • keratomycosis • A niger • Otomycosis most commonest ds caused vy aspergillus • A terries only invasive ds • A flavus • Aflatoxicosis hepatotoxin
- 157. Clinical froms • Allergic broncho pulmonary aspergillosis (ABPA) • Type 1 hypersensitivity • Aspergilloma (fungus ball) • Invasive aspergillosis (angioinvasive) • Paranasal granuloma
- 159. Aspergilloma • A fumigatus (MC) >> a niger (in DM) • Fungus colonizes a tubercular cavity • Fungal ball is a compact mass of mycelia surrounded by fibrous wall
- 160. Invasive aspergillosis • Mc cause A fumigatus • In immunocompromised host • Invades blood vessel disseminate to various organs
- 161. Lab diagnosis • Specimen sputum / transbronchial biopsy • Direct microscopic examination • Hyaline septate hyphae dichotomous branching at acute angle • Culture SDA @ 25 * c
- 162. • European blastomycosis Cryptococcus • N American blastomycosis blastomycosis • S American blastomycosis paracoccidiomycosis
- 163. Zygomycosis or mucormycosis • Fungi of class zygomycetes • Rhizpous or mucor or absidia • These fungi form aseptate or coenocytic hyphae. • They reproduce sexually by zygospore formation • They reproduce asexually by sporangiospore formation. • Predisposing factors • Leukemia/lymphoma/metabolic acidosis/DM
- 164. RHIZOPUS RHIZOIDS ARISE OPPOSITE SPORANGIOPHORE IN RHIZOPUS ABSIDIA RHIZOIDS ARISE IN TERNODAL
- 165. RHIZOPUS
- 166. MUCOR NO RHIZOIDS
- 167. MUCOR
- 168. CF • Rhinocerebral • Serious fuminating infection / angioinvasive /thrombosis/ischemic necrosis of tissues • Pulmonary / gastrointestinal/disseminated/ dermal/ sc
- 169. • Specimen tissue biopsy • Staining • H& E best • Aseptate hyphae irregular branching of hyphae at OBTUSE angle • Culture • SDA @37*c • Dense hairy colony with aseptate hyphae sporangiophore and sporangiospores
- 170. Miscellaneous
- 171. Pencilliosis • Only dimorphic is P marneffi • Causes infn in AIDS pts • Animal reservoir Chinese bamboo rats • Infn acquird by respiratory tract • infects RE sustem
- 172. Dimorphic fungi
- 173. CF • Tuberculosis like illness • Fever • Weight loss • Anemiainvolvement of liver spleen lungs
- 174. • Histology • Ellipsoid yeast cells • Divided by transverse septations (fission) • Stained by PAS /methenamine silver • SDA @ 25 *c • Brush like arrangement of conidia • Produce brick red coloured diffusible pigment
- 175. pneumocystosis • Interstitial plasma cell pneumonia • Opportunistic infn in AIDS • Greater similarity to fungi than protozoa • Hence better classified as fungus • Features in favour of fungi • 16s RNA /attacked by chitinase /lack of intracellular or sexul stage typical of sporozoa/stained with fungal stains • Features in favour of protozoa • 5S RNA/lacks ergosterol/responds better to anti protozoal Rx
- 176. • Morphological forms • Trophozoites, sporozoites and cyst • Trophozoites • Pleomorhic • Fill alveoli of lung • Cysts • Most commonly observed • Oval thick walled • Containing up to 8 sporozoites • Attaches to type I pneumocyte and destroys it • Sporozoites
- 177. CF • Fever with non productive cough • Hypoxia cyanosis progressive dyspnea • Alveolar or interstitial infiltrates • Involves whole of lungs initialy beginning in hilus • CXR perihilar haziness with diffuse mottling • Nosocomial spread • Premature infants/debilitated/malnourished/congenital immunodeficiency
- 178. Lab diagnosis • Specimen BAL lung biopsy sputum • Direct microscopic exmn • Flurescent Ab technique • Cysts • Methenamine silver black • Toluidine blue O red purple • Cresyl etch violet • Sporozoite • Geimsa staining • Basophilic cytoplasm and red purple nucleus
- 179. • Pneumocystis does not respond to antifungals. It is treated by cotrimoxazole.
- 180. Keratomycosis • Invasive fungal infn of cornea • Following trauma • Common agents • A fumigatus ***> flavus/niger/fusarium • Curvularia /candida/ pencillium/alternaria • Diag : Microscopic examn & cuture
- 181. Mycotoxicosis • Illness or death of man or domestic animal caused by food contaminated with mycotoxins • Aflatoxin produced by aspergillus flavus
- 182. Mycetismus • d/t consumption of fleshy fungi • Ergot poisoning d/t consumption of bread made of rye contaminated with claviceps (st anthonys fire/ st vitus dance)
- 185. Muscarinic symptoms
- 186. Psilocybe
- 188. Amanita phalloides massive hepatic necrosis
- 191. Maltese crosses • Babesia microti in PBS • Tetrad forms in RBC’s which represent budding merozoites • Cryptococcus neofromans in polarised light • Paracoccidiosis • Malassezia Cryptococcus neofromans in polarised light
- 192. Otomycosis • fungal otitis externa (9- 10% cases of otitis externa) • hot and humid dimate • aspergillus (A. niger> A. fungatus) 80% • candida is the next most frequently isolated fungus. • Other more rare fungal pathogens include Phycomycetes/Rhizopus/Actinomyces/Penicillium
- 193. • It also occurs in patients using topical antibiotics for treatment of otitis externa or middle ear suppuration. • • Clinical feature: • - Intense itching/ discomfort/ discharge with musty odor. • • On examination: • - A niger appears as black-headed filamentous growth. • - A fumigatus: as pale blue or green growth • - Candida: as white / creamy deposit.