MYCOVIRO - CH 60 of book part 1 Flashcards
Produce large, ribbon-like hyphae that contain occasional septa
MUCORALES (ZYGOMYCETES)
- Have sporangia (saclike fruiting structures) that produce sporangiospores and is formed at the tip of a
supporting structure called sporangiophore
MUCORALES (ZYGOMYCETES)
- Sporangiophores are connected to one another by occasionally septate hyphae called stolons, attached
to contact points where root-like structure (rhizoids) may appear and anchor the organism to the agar
surface.
MUCORALES (ZYGOMYCETES)
- Commonly found on decaying vegetable matter or old bread or in soil
MUCORALES (ZYGOMYCETES)
- infection caused by mucorales
Mucormycosis
can lead to vascular invasion and rapidly produce thrombosis and tissue necrosis - perineural invasion can also occur
Mucormycosis
one of the most common presentation of mucormycosis
- rhinocerebral form
infection w/c involves nasal mucosa, palate, sinuses, orbit, face and brain
- rhinocerebral form
stains for mucorales ID
Calcofluor white or KOH
What to observe under microscope for mucorales ID
observe branching, broad-diameter, predominantly nonseptated hyphae
Cultivation: Fluffy, white to gray or brown hyphal growth, resembles cotton candy
mucorales
grows rapidly; covers agar suface within 24 to 96 hours
mucorales
hyphae may lift the lid of agar plate (aka “lid lifter”)
mucorales
may appear to be coarse - dish is filled with loose, grayish hyphae, dotted with brown or black sporangia
mucorales
Mucorales spp
- unbranched sporangiophores; rhizoids appear opposite the point where stolon arises
Rhizopus spp
Mucorales spp
- singularly produced or branched sporangiophores with round sporangium at the tip; no
rhizoids or stolons
Mucor spp.
Mucorales spp
- pyriform sporangia with funnel-shaped area (apophysis)
- rhizoids originate between sporangiophores as with Absidia spp.
Lichtheimia spp.
- infections caused by dermatophytes involving the superficial areas of the body
Dermatomycoses
- most common fungal infections; referred to as tinea (“ringworm”)
Dermatomycoses
- they break down and utilize keratin as nitrogen source
dermatophytes
- usually incapable of penetrating the subcutaneous tissue unless host is immunocompromised (even then, it is rare)
dermatophytes
gross appearance of lesion of which fungus: outer ring of the active progressing infection, with central healing
dermatophytes
stains for dermatophytes (2)
Calcofluor white or KOH
observe what structures for dermatophytes
presence of hyaline septate hyphae and/or arthroconidia
- infected hair shaft may be seen filled with masses of large arthroconidia in chains (endothrix invasion) or may show external masses of spores that ensheath the hair shaft (ectothrix invasion)
dermatophytes/dermatomycoses
used for final ID of dermatophytes
cultivation
what fungal infection reveal hyphae and air spaces within the shaft
T. schoenleinii
initial growth of dermatophytes is often subcultured onto what agars (2) to induce sporulation
cornmeal agar or potato dextrose agar
- most common causes of feet and nails infection
TRICHOPHYTON SPP.
- most are anthrophilic (“human-loving”), few are zoophilic (primarily infecting animals)
TRICHOPHYTON SPP.
- microconidia: smooth, spherical or pyriform or club-shaped (clavate), thin-walled with 3 to 8 septa;
“birds on a fence”
TRICHOPHYTON SPP.
- macroconidia: singly at terminal ends of hyphae or on short conidiophores
TRICHOPHYTON SPP.
rx for trichophyton
- Rx: terbinafine
- colony: flat or heaped-up, white to reddish, cottony or velvet surface; may be fluffy or granular
T. rubrum
- reverse side: cherry red color produced only after 3 to 4 weeks of incubation
T. rubrum
- macroconidia: cigar-shaped or pencil-shaped; sometimes on granular strain
T. rubrum
- urease (-), hair penetration (-)
T. rubrum
- rapidly-growing; most common cause of athlete’s foot
T. mentagrophytes
2 colonial forms of t. rubrum
fluffy or granular
2 colonial forms of t. mentagrophytes
downy and granular variety
what variety of mentagrophytes from tinea pedis
downy
what variety of mentagrophytes from lesions acquired by contact with animals
granular
- colony: white to cream-colored to yellow, red pigmentation (granular colonies)
T. mentagrophytes
- reverse side: rose-brown
T. mentagrophytes
- microconidia: small, spherical in grapelike-clusters; produced by granular colonies
T. mentagrophytes
- macroconidia: thin and smooth-walled, cigar-shaped with 2 to 5 septa; has a definitive narrow
attachment to the base
T. mentagrophytes
- urease (+); penetrates hair
T. mentagrophytes
CA of tinea capitis;
T. tonsurans
produces circular, scaly patches of alopecia (loss of hair); “black dot” ringworm
T. tonsurans
- slow-growing, enhanced by thiamine or inositol in casein agar
T. tonsurans
- colony: buff to brown, wrinkled and suedelike, shows radial folds and craterlike depression in the
center
T. tonsurans
- reverse side: yellowish to reddish brown
T. tonsurans
- microconidia: with flat bases, located on the sides of hyphae; with age becomes swollen and elongated (balloon forms)
T. tonsurans
- chlamydoconidia in old cultures
T. tonsurans
- causes lesions in cattle and in humans on the beard, neck, wrist and back of hand
T. verrucosum
- chain of large spores are seen in short stubs of hair from lesions
T. verrucosum
- slow-growing (14 to 30 days); enhanced at 35C to 37C, enriched with thiamine and inositol
T. verrucosum
- culture medium: 4% casein and 0.5% yeast extract; can hydrolyze casein
T. verrucosum
- colony: small, heaped and folded with aerial mycelium; ranges from gray and waxlike to bright yellow
T. verrucosum
- reverse side: nonpigmented but may be yellow
T. verrucosum
- chlamydoconidia in chains; antler hyphae
T. verrucosum
- macroconidia: “rat tail” or “string bean”; rarely formed
T. verrucosum
causes tinea favosa or favus;
T. schoenleinii
formation of yellowish cup-shaped crusts or scutulae on the scalp, scarring and permanent alopecia
Tinea favosa
- large inverted cones of hyphae, athroconidia at the base of the hair follicle and branching hyphae throughout the hair shaft;
T. schoenleinii
favic chandeliers and chlamydospores
T. schoenleinii
slow-growing organism (30 days or longer)
T. schoenleinii
- colony: white to light gray, waxy surface, irregular border, submerged hyphae that cracks the agar, nonpigmented
T. schoenleinii
- reverse side: tan or nonpigmented
T. schoenleinii
knobby and club-shaped hyphae
T. schoenleinii
- colony: “port wine” in color (purple), heaped up, verrucous, waxy
T. violaceum
- causes infection of scalp and body; endothrix hair invasion, “black dot” type of tinea capitis
T. violaceum
- very slow-growing; enhanced growth with thiamine
T. violaceum
- reverse side: purple or nonpigmented
T. violaceum
no micro and macroconidia
T. violaceum
has swollen hyphae with granules and chlamydoconidia
T. violaceum
- agent of tinea imbricata
T. concentricum
