the fungi Flashcards
list the medically important fungi
- aspergillus spp
- fusarium spp
- agents of mucormycosis
- dimorphic fungi (histo/blastomycosis/coccidioides)
- dermatophytes/superficial mycoses
what are fungi?
EUKARYOTES that grow without roots, stems or leaves
do not have chlorophyll for photosynthesis
reproduce via SPORE formation
rigid cells walls made of chitin, mannan, cellulose (no peptidoglycan)
have nucleus, nuclear membrane, ER, golgi, mitochondria
what is the cell membrane of fungi made of
sterols
antifungal target
what makes up the cell wall of fungi
chitin, mannan, cellulose
what are yeasts
unicellular (ovid or round)
replicate by budding
smooth, bacteria-like colonies
(type of fungus)
what are molds
multiple cells forming microscopic filamentous mycelium
type of fungus
name 2 yeasts
candida
cryptococcus
name 1 mold
aspergillus
name 2 dimorphic species
histoplasmosis
blastomycosis
coccidioimycosis
superficial fungi
dermatophytes: tinea, Malassezia furfur
yeast
systemic/deep fungi
histoplasma
coccidioides
opportunistic fungi
aspergillus
candida
cryptococcus
pneumocystis
list the medically important yeasts
candida
cryptococcus
pneumocystis jirovecii
candida spp
c. albicans = most common
OPPORTUNISTIC
most common fungal pathogen affecting humans
wide range of disease: superficial musculocutaneous disease to invasive (i.e vulvovaginal cadidiasis, oropharyngeal colonization in healthy adults; systemic infections with 30-40% mortality)
management of candida infection
limited by delay in diagnosis
remove IV lines, catheters, foreign bodies if possible
early IV antifungal targeted versus the specific candida
consult ID
what is candidemia
systemic blood infection of candida
very serious MEDICAL EMERGENCY
cryptococcus spp
environmental yeast (bird poop)
inhalation of basidiospores from enviro leads to disease beginning in lungs
hematogenous spread to brain/bone/skin/joints
pathogenic species = C. NEOFORMANS var. neoformans (classic) and var. grubii, as well as C. GATTII (vancouver island)
greater prevalence in immunocompromised patients
CNS and/or pulmonary involvement; morbidity and mortality rates remain high
describe C. gattii infection in an immunocompetent host
results in “walled off” pulmonary disease (“uncommon pneumonia”)
Pneumocystis jirovecii
P. carinii
yeast-like fungus
all mammals harbour at least one species of pneumocystis
reproduce in mammals lung alveoli (reservoir = mammalian host)
environmental reservoir is undetermined
transmitted via AIRBORNE route–> requires short period of exposure and low inoculum
most people are seropositive by 2-4 years old
leading opportunistic infection in AIDS patients–> defining condition–>nonproductive cough, chest tightness, night sweats, low grade fever, tachypnea
aspergillus spp
environmental mold (requires environmental substrate for growth
5-6 are pathogenic
A. fumigatus, A. falvus, A. terreus, A. niger
sinusitis, skin infection are most common
filamentous fungi