3. Mycology
Greek – mukes – fungus
Candida was described early as 1839
But fungi were not studied till recently
because most infections are mild
After bacterial infection control
developed, fungal infections became
more common
Fungi cause serious infections in
immunosupressed and those on
steroid treatment
11. Superficial mycoses
Affect skin, hair, nails and mucous
membranes
Include
Candidosis
Pityriasis versicolor
Tinea
Pedra
dermatophytosis
12. Candidosis
Usually superficial – infect skin, nails
and mucous membranes
Systemic infection in
immunosupressed
Yeast and hyphae – dimorphic fungus
19. Pityriasis versicolor
Areas of depigmentation or
hyperpigmentation on skin of trunk,
abdomen and upper limbs
Diagnosis by skin scrapings – yeasts
seen
20.
21. Tinea nigra
Infection of palms
Black or brownish lesions
Hyphae and budding yeasts on smear
Cultured on SDA, green to black
colonies
27. Dermatophytosis
Skin, hair and nails
a/k/a tinea or ring worm
About 40 of them are known
Classified on the basis of type of
colony on SDA and spores they
produce
38. Mycetoma
Infection of subcutaneous tissue of
foot
Reported from Madurai – a/k/a
madura foot
Multiple sinuses are seen in foot
discharging pus onto surface
Pus contains ‘sulfur granules’ which
are colonies of fungi
44. SPOROTRICHOSIS
Fungus found on thorns
Infection seen in gardeners
Nodules are seen in skin, along
lymphatics and lymphnodes
Upper limb
Caused by fungus Sporothrix
schenckii
51. Systemic mycoses
Affect multiple body systems, usually spread through
blood stream
Two groups
True pathogens – cause disease in healthy
• Histoplasma
• Blastomyces
• P. marneffei
Oppurtunistic pathogens – cause disease in
immunosupressed
• Candida
• Aspergillus
• Zygomycetes
Other
• Cryptococcus neoformans
53. Fungus is inhaled
Can cause pneumonia, meningitis,
skin ulcers etc.
Diagnosis by demonstration of
capsulated budding yeast in
CSF/sample
India ink is used to demostrate
capsule
56. Histoplasma
Grows as mold in nature, yeast in
tissues
Most common in USA
In India found in west bengal
Found in bird feces
Inhaled – lung infection, may spread