Mycology and Virology Past Paper PDF

MICRO2 | Mycology and Virology BACHELOR OF SCIENCE IN MEDICAL LABORATORY SCIENCE 3 - 2 MIDTERMS: LESSON 5: Agents of Subcutaneous Mycoses SUBCUTANEOUS MYCOSES  Affect subcutaneous tissue  Usually result of traumatic implantation of forei...

MICRO2 | Mycology and Virology BACHELOR OF SCIENCE IN MEDICAL LABORATORY SCIENCE 3 - 2 MIDTERMS: LESSON 5: Agents of Subcutaneous Mycoses SUBCUTANEOUS MYCOSES  Affect subcutaneous tissue  Usually result of traumatic implantation of foreign objects into the deep layers of the skin, permitting fungus to gain entry into the host. Any thorn or contaminated objects with the different fungal found in the soul or decaying of organic matter, that would be the entrance of subcutaneous mycoses in to the host o Causative agents—organisms typically found in soil or decaying vegetation  Infections may be grouped by either the  These are the different manifestations of o disease processes they cause chromoblastomycosis o causative agents involved  LETTER A, lower leg. It is a lesion and it has been  Coccidioidomycosis, the most fatal of all the fungal occurring in the past 3 months. This is a lesion of infections, this is common some parts of the US, in chromoblastomycosis Arizona, California, desert areas  LETTER B, knee. There are confluent nodular lesions. CHROMOBLASTOMYCOSIS  LETTER C, tumor like lesion like a cauliflower  Also known as verrucous dermatitidis and  LETTER D, cicatrisation lesion with verruca showing chromomycosis serpiginous and verrucous contours o Nodules become ulcerated and crusted  LETTER E, hyperkertotic, highly keratinzed verrucous  Chronic infection acquired by traumatic inoculation lesion into skin and subcutaneous tissue. After the traumatic  LETTER F, thigh. Purplish soft-flat lesion. introduction the symptoms would not develop LABORATORY DIAGNOSIS instantly, it would take months to years before you  10-40% KOH have the symptoms  Direct mycological examination o Develops over months to years  Histopathology  Cauliflower or tumor-like lesions revealing sclerotic o The presence of muriform cells, this is your bodies and resembling copper pennies sclerotic bodies, it is a confirmatory diagnosis  Cladophialophora spp., Fonsecaea monophora, F. o Fungal elements are most commonly found within pedrosoi and Phialophora verrucosa these agents are dermal macrophage and mainly consists of phaeoids or dematiaceous, it means to say they are sclerotic bodies that are usually 5-12 dark in color micrometers in diameter  Dematiaceous molds o Moderate to slow growth o Velvety to wooly, gray-brown to black due to the presence of melanin in their cell wall o Differentiate by characteristic structures AGENTS OF CHROMOBLASTOMYCOSIS  Cladophialophora o These are the characteristic of muriform cells, o Septate hyphae occur in tissue thick walled and can appear singly or in  Phialophora multiple clusters o Sclerotic bodies and septate hyphae are found o This is a skin biopsy, we have here in subcutaneous tissue hyperkeratosis and pseudoepitheliomatous o Hyphae may be found in joints hyperplasia, the stain used is Hematoxylin-Eosin.  Fonsecaea o Within the dermis, we can see inflammatory cells. o Sclerotic bodies are observed in subcutaneous We have macrophages and lymphocytes as tissue well as plasma cells and neutrophils o Septate hyphae are observed in brain and in o In the arrow, there are brownish color, these are lung tissue the sclerotic bodies.  Immunodiagnosis | CALINDAS, TRISHA FELICITTY S.  Conidia Conidiophore o ELISA, you have to detect the presence of antigens from the agents of chromoblastomycosis o Immunodiffusion  LETTER A, you have to scrape the black dot where it is being pointed. The black dot shows you muriform cells without germination  LETTER B, without germination  LETTER C, with germination  Phialophora verrucosa, colony using Malt Extract  Germination will result in the formation of filaments Agar after 3-4 weeks of contribution at 30 degrees  We can also have a biopsy aside from the black dot celcius. Conidiophores are conidogenous cells scrape. We can perform H&E staining, it would phaeoid, flask shapes and the presence of colorettes. showcase hyperkeratosis and The conidium are oval in shape, single-celled. pseudoepitheliomatous hyperplasia because of the  Fonsecaea pedrosoi, colony using Malt Extract Agar presence of macrophages, giant cells, plasma cells, after 3-4 weeks of contribution at 30 degrees and neutrophils that would contribute to hyperplasia celcius. The conidiophore, sympodial and angular.  LETTER E, violet part is the muriform cells and they They are single-celled. The conidia, there is a are found in the Langerhan cells of your tissue primary and secondary. They are closely similar to Cladophialophora spp., the only difference is that MICROSCOPIC MORPHOLOGY OF FUNGI CAUSING there is more erected and more branching single- CHROMOBLASTOMYCOSIS celled blastoconidium in Cladophialophora spp. it is similar to Rhinocladiella spp. however, there are longer conidiophore, also it is erect and they are also sympodial, however there is a longer conidiophore.  Cladophilophora carrionii, erected conidiophore, single-celled but are branching.  Rhinocladiella aquaspersa, the conidiophore is also erect, they are dark and have conidia. Only found on the upper portion near the tip. The conidoa are elliptical, single-celled, and sympodially arranged. CONIDIA OF PHIALOPHOTA VERSUS CLADOPHIALOPHORA | CALINDAS, TRISHA FELICITTY S.  ADDITIONAL PICTURES  LETTER A, Phialophora  The individual condium could measure 3-5 by 1.5- 3.5 micrometers and they are aggregated and clustered and apices of the phialide.  While the conidia of Cladophialophora, specifically Cladosporum carrionii, the precence of lemoniform to fusiform. They are smooth and slightly verrucous and could be pale olivaceous. PHIALOPHORA VERRUCOSA  LETTER A, flask-shaped  LETTER B, colorette  LETTER C, conidia EUMYCOTIC MYCETOMAS  Uncommon in the United States  Subcutaneous and cutaneous tissue infection o Swelling and exudates (fluids produced from infections) draining to skin surface  Found mostly in tropical and subtropical regions  Infections occur in those who have outdoor occupations  Chronic granulomatous infection usually involving the lower extremities  Dissemination may occur, but it is rare  Most common: o Pseudallescheria boydii (teleomorph) sexual  Cleistotheicia | CALINDAS, TRISHA FELICITTY S.  o Scedosporium boydii (anamorph) asexual  It is your sexual, an individual cleistothecia that have  Single oval conidia ascospores. o Fusarium (Acremonium) falciforme  Mucoid clusters of single or two-celled, PHAEOHYPHOMYCOSIS slightly curved conida borne from phialides  Infections from brownish yeast-like cells, at the tips of long, unbranched, multiseptate pseudohyphae, or hyphae conidiophores  Subcutaneous, localized or systemic infection o Madurella spp.  Cladiophialophora bantiana, Rhinocladiella machenziei,  Produce conidia from the tips of phialides, Verruconic gallopava, Exophiala, Alternaria, but many remain sterile Exsorohilum, Bipolaris, and Culvularia spp. DESCRIPTION OF GRANULES AGENTS OF PHAEOHYPHOMYCOSIS  Alternaria- fluffy and gray to gray-brown or gray- green  Bipolaris- gray-green to dark-brown colonies  Curvularia- similar to Alternaria  Exophiala jeanselmei- gray-green to dark-brown colonies  E. dermatitidis- gray-green to dark-brown colonies  Exserohilum- gray-green to dark-brown ACTINOMYCOTIC MYCETOMA DEMATIACEOUS GENERA INCITING SUBCUTANEOUS PHAEOHYPHOMYCOSIS SCEDOSPORIUM BOYDII ALTERNARIA  Golden-brown hyphae  Large brown conidia resembling a drumstick  Horizontal and longitudinal septa  You could see single, oval conidium CLEISTOTHECIA CONTANING ASCOSPORES  Looks like a drum stick and then it has a horizontal as well as longitudinal septa. It is alternating from dark to light. | CALINDAS, TRISHA FELICITTY S. ADDITIONAL PICTURES ADDITIONAL PICTURE CURVULARIA  Geniculate conidiophores  Conidia o Golden brown o Multi-celled o Curved o Swollen central cell BIPOLARIS  Bent conidiophores  Oblong conidia arranged sympodially  Hilum protruding slightly  Germ tubes at one or both ends  This is a distinguishing characteristic, the swollen central cell, making it like twisted curved conidia ADDITIONAL PICTURES  So bent at sharp angles are called geniculate  They have melanin, so it is brown in color | CALINDAS, TRISHA FELICITTY S.  EXOPHIALA  Exophiala jeanselmei o Slow grower o Shiny brown colonies o Velvety with age o Elongated conidiophore with tapered tip o Uses potassium nitrate o Grows only at 37°C ADDITIONAL PICTURES  Exophiala dermatitidis o Slow grower o Shiny black colonies o Velvety with age o Elongated tubular annellophores o Does not uses potassium nitrate o Grows at 37°C and 40°C to 42°C CONIDIA OF EXOPHIALA SPP. ADDITIONAL PICTURES  Born at the tips of annelide CONIDIA OF EXOPHIALA DERMATITIDIS | CALINDAS, TRISHA FELICITTY S. DIRECT DETECTION o Yeast  Microscopic preparation of tissue during surgery or  2 to 4 μm in diameter; oval or elliptical in autopsy shape, often in a single bud  Calcofluor white or fluorescent microscopy  Cigar-shaped forms measuring to 3 to 10  Fontana-Masson stain μm o Useful to detect melanization that may appear YEAST AND MOLD PHASES OF S. SCHENCKII as a hyaline mold  Mycetoma or Phaeophomycosis o Microscopic granules from lesions o Pigmented hyphae using hematoxylin-eosin or unstained histopathologic sections o Methenamine silver stain or Fontana-Masson stain NUCLEIC-ACID DETECTION  Polymerase Chain Reaction o Normally sterile body fluids  Nucleic acid based sequencing o Ribosomal genes  High-Resolution multi-gene typing systems o Epidemiologic purposes  Cigar-shaped yeast cell CULTIVATION  May represent pathogens, more frequently transient microbiota, inhaled spores or contaminants  Cultured from sterile body sites are significant  Interpretation should be in conjunction with direct detection methods  We cannot use contaminated sampled, in which there are high numbers of indigenous microflora ANTIFUNGAL SUSCEPTIBILITIES  Susceptibilities are known for most relevant species  Interpretative breakpoints have not been established  Amphotericin B and Azoles are generally effective  Arranged as flowers or rosettes, mold form SPOROTHRIX SPP. / “ROSE GARDENER’S” DISEASE SPOROTHRIX SCHENCKII SPECIES COMPLEX  Most common presentation  Causative agent of Rose Gardener’s Disease o Lymphocutaneous sporotrichosis o Nodular and ulcerative lesions  Worldwide distribution o Found in soil and decaying vegetative matter  Particularly plants, wood splinters, and rosebush thorns  Colonies o Gray-white but may turn buff, brown, or brown- black as it matures  Microscopically o Mold  It was first observed from people handling rose  Delicate hyaline, septate hyphae plants  Oval, smooth conidia 2 to 4 μm in diameter supported by a delicate hairlike conidiophore  Arranged laterally along hyphae or in daisy-like clusters | CALINDAS, TRISHA FELICITTY S. ADDITIONAL PICTURES ENTOMOPHTHORALES AND BASIDIOBOLALES  Basidiobolus ranarum  Conidiobolus spp.  Present in soil, decaying vegetable materials, and animal feces  Occur predominantly in immunocompetent individuals DISEASE  Basiodobolomycosis o Subcutaneous tissue of arms, legs, buttocks, trunk, perineum, face, or neck o Woody, hard, painless nodule  Conidiobolus spp. o Infect tissue around nose and on the face o Inhalation of spores or following trauma LABORATORY DIAGNOSIS RHINOSPORIDIUM SEEBERI  Mesomycetozoea protistal eukaryote  Direct detection methods o Morphologically similar to Coccidiodes o Splendore-Hoeppli phenomenon  Organism is found in aquatic environments and  PCR for Basidiobolus entomophthoromycosis resistant spores are present in terrestrial  Culture environments  Route of transmission is unknown o Likely by exposure to spores through breaks in the skin or mucous membranes  Infection results in formation of painless polyps on the mucosa of the nose, eye, larynx, genitalia, and rectum  Rhinosporidiosis o Greater than 300 μm spherical sporangia with endospores and negative culture  Tissue biopsies are the preferred method for diagnosis  Wet mount from polyps demonstrating sporangia and endospores are often present  This is the Splendore-Hoeppli phenomenon TREATMENT OF PARAFUNGALS  The organisms are resistant to antifungals  R. seeberi o Surgical removal of infected tissue and polyps is required LACAZIA LOBOI  Lobomycosis o Rare granulomatous zoonotic fungal infection o Leprosy-like lesions and nodules  Organisms found in soil, on vegetation, and in aquatic animals  Transmission results from traumatic injury or from contaminated water  Asteroid bodies, an in vivo formation of intensely o Dolphin to human and human-to-human eosinophilic material, which is activated due to transmission has been reported allergic reactions. Immune complexes that would try  Diagnosis is by microscopic morphology to surround your fungal elements o Yeast-like cells in chains, connected by tubules IDENTIFICATION  Basidobolus ranarum o Colonies appear slightly yellow with radial folds | CALINDAS, TRISHA FELICITTY S.  o No aerial hyphae present  Conidobolus spp. o Primary conidiophores have swollen apices with o Fast growing fungus globose spores o Produces hyaline, radially folded colonies o Secondary conidia appear pyriform with a o Initially appear waxy and become powdery knob-like adhesive tip o Primary conidia are spherical and have prominent papilla o Zygospores are absent when grown on potato dextrose agar  With a satellite colony  Like villain or like projections  Germinating conidia with zygospores  Colonies showing satellite from forcibly discharged conidia  Swollen sporophore | CALINDAS, TRISHA FELICITTY S.