MYCO Flashcards
(Chytrids)
Chytridiomycota
(Yeast and Sac fungi)
. Ascomycota
bread molds)
Zygomycota
FUNGAL FORMS
- Yeasts
- Molds
- Mushrooms
(club fungi)
Basidiomycota
The study of fungi that impacts human health
MEDICAL MYCOLOGY
Fungal infection involving only the skin and/or Hair
SUPERFICIAL
– A chronic,
superficial fungal disease of the skin characterized by well
demarcated white, pink, fawn, or brownish scaly lesions.
. Pityriasis versicolor/ Tinea Versicolor –
- Lacks immune response from host
- No living tissue invaded
- Asymptomatic
- SUPERFICIAL
. Pityriasis versicolor/ Tinea Versicolor Etiological Agent-
Malassezia species
Characterized by appearance, primarily on
palms of the hand and occasionally the plantar and the other
surfaces of the skin as brown to black non-scaly macules
b. Tinea nigra
White Piedra Etiologic Agent-
Trichosporon spp.
b. Tinea nigra Etiologic Agent-
Hortaea werneckii (Exophiala
werneckii, Phaeoannellomyces werneckii,
Cladosporum werneckii
Fungal infection of the hair shaft with soft
greyish nodules
White Piedra
d. Black Piedra Etiologic Agent-
Piedraia hortaea
chronic localized disease of the skin
and subcutaneous tissues, characterized by crusted, warty
lesions usually involving the limbs.
Chromoblastomycosis
hard black nodules on the shafts of the
scalps, beard, and pubic hair/ - does not penetrate hair follicle, scalp hair are rough and
sandy
d. Black Piedra
. Sporotrichosis caused by?
Sporothrix schenckii
- fungal infection involving only the skin, hair and nails - pathological changes and inflammatory response occur in
the host. - Symptomatic
CUTANEOUS
Manifestations: Ulcer discharging viscous, purulent fluid with
varying size granules
mycetoma
Rose gardener’s disease
. Sporotrichosis-
- chronic, slowly progressive granulomatous
infection. - Infection in subcutaneous or skin tissue -
Maduramycosis or Madura Foot
a. Mycetoma-
also called Tinea or Ringworm - Disease of the nails, hair, and skin caused by
filamentous fungi called Dermatophytes
a. Dermatophytosis –
Chronic, localized infections of the skin and subcutaneous
tissue following traumatic implantation of causative agent - Agents of subcutaneous mycoses usually inhabit the soil - caused by fungi with saprophytic existence in nature.
SUBCUTANEOUS
Chronic subcutaneous lesions - Does NOT produce sclerotic bodies
Phaeohyphomycosis-
Chromoblastomycosis etiologic agents
Cladophialophora carrionii,
Fonsecaea species complex Phialophora verrucosa
- Subcutaneous noduloulcerative lesions
. Sporotrichosis-
hronic subepidermal infection - Characterized by Keloidalm Verrucois, Nodular
lesions
e. Lobomycosis-
e. Lobomycosis causative agent
Lacazia loboi
an intracellular mycotic infection of the
reticuloendothelial system
Histoplasmosis
Fungal infections that invade the deep organs
- SYSTEMIC
- Predominantly affect people with immunocompromising
conditions, however, some mycoses known as the endemic
mycoses can cause disease in healthy individuals.
- SYSTEMIC
two types of systemic infection
dimorphic, oppurtunistic
a. Blastomycosis
Clinical Manifestations-
o Pulmonary Blastomycosis
o Cutaneous Blastomycosis
o Osteoarticular Blastomycosis
. Blastomycosis EA?
Blastomycoses dermatitidis
initially a respiratory infection that
mat progress to a chronic pulmonary condition to a systemic
disease involving meninges, bones, joints, and subcutaneous
and cutaneous tissues.
Coccidioidomycosis
Coccidioidomycosis EA?
: Coccidioides immitis
Histoplasmosis- most common variant
Var. capsulatum
Histoplasmosis Lymphangitis
in horse
Var. Farciminosum-
Histoplasmosis african type
Var. Duboisii-
. Paracoccidioidomycosis
Clinical Manifestations:
o Pulmonary Paracoccidioidomycosis
o Mucocutaneous Paracoccidioidomycosis
o Lymphonodular Paracoccidioidomycosis
o Disseminated Paracoccidioidomycosis
Paracoccidioidomycosis EA?
Paracoccidioides brasiliensis
Geographic Distribution: South America and Central
America
Paracoccidioidomycosis
Talaromyces marneffei infection EA?
: Talaromyces marneffei
Talaromyces marneffei infection
Clinical Manifestions:
Normal immunity:
Disseminated or Focal (Mimics
TB)
Talaromyces marneffei infection
Clinical Manifestions:
Immunosupressed:
Disseminated (Mimics
Cryptococcosis/ Histoplasmosis)
- Fungal elements appear as gram-positive or gram-
negative.
Gram Stain
– Differential staining technique based
on bacterial cell wall structure
Gram Stain
breaks down the proteinaceous components of
the host cells without altering the structure of the
fungal elements that are present
KOH
o Can be helpful in revealing fungal elements
in wet mounts when examined under a
fluorescence microscope
KOH with Calcfluor White
is a
compound that stain the fungal cell wall
calcofluor white
- AB test
- Immunodiffusion
- Radioallergosorbent Test (RAST)
negative stain
o Used for Cerebrospinal Fluid
India Ink-
The polysaccharide capsule of cryptococcus
spp exclude the ink particles giving a “clear
halo: around the organism
India Ink-
- AG test
- Latex Agglutination - Radioimmunoassay
Eukaryotic unicellular fungi
Reproduces by budding
Moist to waxy colonies
Round to oval
Elongate or irregular in shape
YEAST
Yeast cell membrane
D Ergosterol
YEAST cell wall
Chitin also L-glucans and Mannans
- Primary Isolation Medium for Yeasts - Acidic pH 5.0 - High concentration of suga
a. Sabouraud Dextrose Agar
SDA with chloramphenicol and cycloheximide - Selective medium for isolation of fungi
. Mycosel Agar
test to determine if isolated colony is
bacteria or yeast
a. Wet Mount
- used to differentiate Candida albicans and
Candida dubliniensis from other yeast
b. Germ tube
- Corn meal with tween 80 agar test - For distinguishing various species of Candida and
other yeasts
. Dalmau Plate Method
The basic structural unit of mold is?
Hypha
mold Divided into cells by the development of
Cross-walls
(septa)
mold observe growth in?
Mycosel agar
mold reproduce by?
conidia
Lactophenol Cotton Blue (LPCB) Mount: – kills any live microorganisms
Phenol –
Disadvantage:
o Only superficial structures of fungi tent to
stick to the tape
o Rarely used technique because of
inconvenience
. Scotch Tape Method/ cellophane tape method
lactophenol Cotton Blue (LPCB) Mount: Preserves fungal structures
. Lactic Acid
Advantage
o Compared to tease mount technique,
morphology appears intact
- Scotch Tape Method/ cellophane tape method
lactophenol Cotton Blue (LPCB) Mount: Stain the Chitin present in the fungal cell wall
Cotton blue
- Disadvantage: morphology is not intace
- Tease Mount Technique
holoblastic or enteroblastic)
Conidium wall
(clamps, spiral, favic, chandelier)
Hyphal Structure (
CONIDIODENOUS CELLS TYPES OF CONIDIOGENOUS
CELLS
- Annelids
- Phialide
- Thallic Conidiogenesis
(ascomata, Ascospores,
sporangiospores)
Sexual structures
• Classic pigment & morphology, but not necessarily the best primary growth or sporulation.
• Poor recovery of dermatophytes and other groups of organisms.
Sabouraud’s Dextrose
Agar (SDA)
- Enhances reproductive structures production
• Enhances colony color
Potato Dextrose or
Flakes Agar (PDA/PFA)
• Enhances growth of dimorphic fungi
Brain Heart Infusion Agar
Contains both CHLORAMPHENICOL (inhibits bacterial growth) and CYCLOHEXIMIDE (inhibits saprobic fungi and some opportunists and true pathogens)
Mycosel Agar
• Partially differential and selective for dermatophytes.
* With antibiotics to inhibit bacteria
• With cycloheximide to inhibit most non-dermatophytes
* With indicator to demonstrate increase in pH = consistent with dermatophyte growth.
Dermatophyte Test Medium