Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
98 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
what are the 3 groups of fungi?
|
yeast
mold mushrooms (but we don't care) |
|
|
|
which mold makes aflatoxin?
|
aspergillus flavus
|
|
|
|
who are the most likely pts for opportunistic mycoses?
|
immunosuppressed
(cancer, transplant, AIDS, autoimmune, DM, long-term hospital) |
|
|
|
what are the specific risk factors for mycoses?
|
inappropriate use of broad spectrum antibiotics
radiation chemo corticosteroids surgery catheterization |
|
|
|
what fungus is the most important one in medicine/dentistry?
|
candida
what are some features? |
normal flora, colonize soon after birth
held in check by natural defenses may become opportunistic |
|
|
what is thermal dimorphic conversion?
|
yeast at 37° (body)
mold at 25° (lab) |
|
|
|
what is the fungus if you see yeast w/in a macrophage?
|
histoplasma capsulatum
|
|
|
|
if you see "encapsulated yeast" what is it?
|
cryptococcus
|
|
|
|
what is a germ tube?
what is it for? |
elongated appendage growing from yeast cell
adherence penetration (proteases) |
|
|
|
what are hyphae?
|
long strand or filament of cells
|
|
|
|
which fungus has septate hyphae?
which 2 have nonseptate? |
sepatate - aspergillus
nonseptate - mucor & rhizopus |
|
|
|
which 2 fungi are assoc w/ DM?
|
rhizopus
mucor |
|
|
|
what does mycelium refer to?
|
mat of hyphae
|
|
|
|
what is a spoangiospore?
conidium? sporangiophore? conidiophore? |
sporangiospore = w/in sporangium (produced w/in the sac)
conidium = from conidiophore - open & not enclosed in sac sporangiophore = stalk that bears sporangium conidiophore = hypha branch that bears conidia |
|
|
|
arthroconidia
blastoconidia chlamydoconidium |
arthro = hypha fragmenting
blasto = by budding chlamydo = swollen hypha; linked to survival in adverse environment |
|
|
|
microconidium - what is 1 example?
macroconidium - what is 1 example? |
micro = unicellular –– trichophyton
macro = multicellular –– microsporum |
|
|
|
what are the 4 types of mycoses?
examples (i.e. the ones Dr Jensen pointed out)? |
systemic (=endemic) –– cocci
subcutaneous –– sporotrichosis & mycetoma dermato- (=superficial) –– thrush & dermatophytes opportunistic –– candidiasis & cryptococcus |
|
|
|
are toxogenic virulence factors assoc. w/ mycosis?
|
no
(e.g. no exotoxins or endotoxins) |
|
|
|
what are the virulence attributes of candida?
|
•biofilms (adherence)
•germ tubes & hyphae for tissue invasion •extracellular enzymes to break down tissue |
|
|
|
lab id considerations
are most fungi aerobes or anaerobes? mold vs. yeast - which grows rapidly? which takes weeks to mature? what do lab workers need to be careful about? |
aerobes
yeast grows rapidly mold may take weeks to mature avoid inhaling spores |
|
|
|
what are 2 common media for ID of fungi?
|
sabouraud agar (SDA)
potato dextrose agar (PDA) |
|
|
|
what 4 things do antifungals target?
which one is most commonly targeted? |
•cytoplasmic membrane sterols (most common = -azole)
•cell wall components •NA & protein synthesis •mitotic spindle formation |
|
|
|
pathogenesis of superficial candidiasis:
who gets mucosal infections? who gets skin infections? what does candidal paronychia refer to? what do you see w/ systemic? |
mucosal - immunosuppressed, contraceptives, antibiotic use
skin - elderly & obese candidal paronychia = inflammation around nails systemic - respiratory, UTI, candidemia |
|
|
|
what is a "true pathogen"?
|
causes disease in healthy host, more severe disease in immune compromised host
|
|
|
|
what pts are susceptible to opportunistic mycoses?
|
immunosuppressed
smoking pregnancy age diabetes |
|
|
|
which fungi cause opportunistic mycoses?
|
ANY fungus found in nature may give rise to opportunistic mycoses!
we learned about candidiasis, cryptococcosis, aspergillosis, PCP |
|
|
|
what are the 3 most common candida infections?
|
c. albicans / c. dubliniensis
c. tropicalis why is it important to distinguish b/w albicans & dubliniensis? |
need to know for treatment – dubliniensis is more resistant to azoles
|
|
|
which candida is most resistant to azoles?
|
c. glabrata
what else is special about glabrata? |
it is the only species that forms ONLY yeast cells (no 2° structures)
|
|
|
which 2 candida species form germ tubes?
|
albicans & dubliniensis
|
|
|
|
how are pseudohyphae produced?
|
produced when budding cells fail to detach from each other
|
|
|
|
why is sputum not useful for candida diagnosis?
|
candida is NORMAL FLORA
|
|
|
|
why is chromagar useful for diagnosis of candida?
what other media are used? |
each species will grow as a differently colored colony. it is selective & differential
SDA, PDA, routine bacteriological media |
|
|
|
which sugar is the most cariogenic? why?
|
sucrose
it's a substrate for lactic acid fermentation used by s. mutans ⇒ glucan ⇒ adherence |
|
|
|
what are the 4 factors in development of caries?
|
plaque microorganisms
host factors (teeth, saliva, hygiene) time diet (carbs as substrate) |
|
|
|
which yeast prefers CSF?
|
cryptococcus neoformans
what is the resultant disease? |
meningoencephalitis (fever, HA, stiff neck, ∆ mental status) = fatal
|
|
|
why is cryptococcus gattii scary?
|
it is an emerging infection that affects immunocompetent
where is it found? |
pacific NW
|
|
|
what medium differentiates b/w cryptococcus gattii & neoformans in the lab?
|
use CGB medium
(canavanine glycine bromothymol blue) what should you see? |
gattii ⇒ color ∆ to blue
neoformans ⇒ color stays yellow |
|
|
what happens w/ inhlation of aspergillus?
how about ingestion? |
inhale ⇒ severe allergic reaction
ingest ⇒ mycotoxicosis, hepatocellular & colon carcinomas |
|
|
|
what are the infective & replicative forms of pneumocystis jiroveci?
|
infective = cysts
replicative = trophozoite |
|
|
|
what does a + test result mean for pnyeumocystis?
|
+ results ≠ definitive dx
b/c ~20% of population carries |
|
|
|
what fungus is erythema nodosum assoc. with?
|
coccidioides
is it good or bad? |
good prognosis
means the pt's CMI is working |
|
|
what stain is used w/ cocci?
|
PAS
|
|
|
|
name the region for the following:
coccidioides histoplasmosis blastomyces paracoccidioides brasiliensis |
cocci = SW
histo = Ohio & Mississippi river valley blastomyces = Ohio & Mississippi river valley p. brasil = Andes mountains |
|
|
|
which fungus has a "broad-based" bud?
|
blastomyces dermititidis
|
|
|
|
what is the role of each of the following, with respect to dental caries?
actinomyces viscosus veillonella s. mutans lactobacillus spp. |
actinomyces viscosus = implicated in root surface caries
veillonella = ANTIcariogenic s. mutans = initiaition of caries lactobacillus spp. = progression of caries |
|
|
|
what is a the virulence factor given for s. mutans?
|
glucosyltransferase
what does it do? |
sucrose ⇒ glucan ⇒ adhere to tooth surface
|
|
|
what shift in bacteria occurs w/ periodontal disease?
|
increase # of gram – bacteria
also more anaerobic b/c pockets create a good environment for them |
|
|
|
which oral cavity bug is black pigmented?
|
porphyromonas gingivalis
what disease is it assoc. with? |
chronic periodontitis
|
|
|
which 2 bugs are assoc. w/ aggressive periodontitis?
|
capnocytophaga spp.
aggregatiobacter acinomycetemcomitans who gets aggressive periodontitis? |
it's rare
young patients F>M Asian, West Africans assoc. w/ immune deficiencies familial clusters |
|
|
how are caries diagnosed?
|
by a dentist. here is what they look for:
visual - white spot on enamel (early), fissure lesions (often brown), root lesions (leathery), cavitation quantitative light-induced fluorescence tactile - probe for texture |
|
|
|
how does fluoride help your teeth?
|
makes minerals less soluble in acid
promotes remineralization messes w/ bacterial membrane permeability & metabolism what happens w/ too much fluoride while teeth are developing? |
fluorosis
staining/damage to enamel that is permanent |
|
|
what are the symptoms/characteristics of ANUG?
what is NOT seen? |
red, inflammed, shiny, bleeding, uncerating gingiva
pseudomembrane halitosis metallic taste pain NO lymph nodes, fever, malaise what are the 3 components of dx of ANUG? |
fusobacteria
spirochetes leukocytes |
|
|
what is noma?
|
extremely severe form of ANUG
what pts get it? |
young kids <10yo in developing nations
seen w/ malnourishment & recent infection (viral or TB) |
|
|
what are the 4 dentoalveolar infections?
|
•dentoalveolar abscess
•ludwig's angina •periodontal abscess •cervicofacial actinomycosis |
|
|
|
what are the most common causes of dentoalveolar abscesses?
|
prevotella
porphyromonas fusobacterium what is the tx? |
drain pus & remove source of infections
antibiotics if fever present |
|
|
what are the causes of ludwig's angina?
|
it's polymicrobial:
prevotella porphyromonas fusobacterium anaerobic streptococci what is a unique feature (vs. caries and all that other junk)? |
PAIN
|
|
|
what disease has gritty pus?
|
cervicofacial actinomycosis
what is the ds assoc with? what is the treatment? |
assoc w/ trauma or invasive oral procedures
tx: surgical drainage, long-term penicillin |
|
|
what is a herpetic whitlow?
|
finger lesion seen w/ 1° herpes infection
|
|
|
|
what bug forms "molar tooth colonies" on BAP at 37°?
what is the micro morphology? |
actinomyces israelii - gram + branched bacilli
what is the ds it is assoc with? |
cervicofacial actinomycosis
|
|
|
what are the % + serum for HSV 1 & 2?
what is the significance? |
~80% + for HSV1
~20% + for HSV2 serology isn't useful for dx |
|
|
|
what 3 things are in the HSV envelope?
|
attachment proteins
fusion proteins structural proteins |
|
|
|
where do latent HSV infections occur?
|
persist in neurons
esp. trigeminal ganglion |
|
|
|
what is seen w/ HHV3?
|
VZV reactivation
sharp line of demarcation, esp midline |
|
|
|
what 4 clinical diseases did we learn for coxsackie A?
|
•herpangina (vesicular, ulcerated lesions around soft palate/uvula)
•hand-foot-and-mouth ds (vesicular lesions) •aseptic meningitis •gastroenteritis what are the characteristics of this virus? |
enterovirus
+ssRNA small, no envelope icosahedral capsid |
|
|
what is the epidemiology of coxsackie A?
|
summer
kids poor sanitation & crowding humans only fecal-oral route |
|
|
|
what are the 3 vaccines for rotavirus & what are their characteristics?
|
•rotashield - live attenuated
from rhesus monkey removed from market due to intussusception •rotarix - live attenuated monovalent GI strain 2 doses over 2 months •rotateq - live attenuated 5 reassorted viruses (human, bovine) G1-4 & L1A 3 doses (2,4,6mo) |
|
|
|
who is susceptible to rotavirus?
what season? size of inoculum? |
kids <2yo
winter (spreads from W→E of US, from Oct→April) small inoculum |
|
|
|
what bug is enterotoxin NSP4 associated with?
what does it do? |
rotavirus
enterotoxin NSP4 mobilizes Ca2+ from ER → enterocyte loses H2O & electrolytes |
|
|
|
what are the characteristics of rotavirus?
|
dsRNA in a non-enveloped icosahedral capsid
segmented genome (11) 6 structural, 5 non-structural proteins |
|
|
|
what are the 4 parts of the 2 receptor model of rotavirus?
|
1 - virion binds at cell surface receptor
2 - NSP4 produced in cell released into lumen 3 - NSP4 binds at separate specific receptors on adjacent cell 4 - stimulate secretory pathways |
|
|
|
what triad is seen w/ rotavirus?
how long does it last? |
triad = fever, vomiting, watery diarrhea
lasts 5-7d |
|
|
|
what is special about the capsid of enteric adenoviruses?
what serotypes did we discuss? |
acid resistant capsid
serotypes 40 & 41 |
|
|
|
what is seen clinically w/ enteric adenoviruses? how long does it last?
|
5-12d
diarrhea, fever, vomiting who gets infected? |
infants
|
|
|
what are the features of caliciviruses?
|
non-enveloped ssRNA
sapporovirus noroviruses what ages get infected? what causes the infection? |
kids & adults
seafood & shellfish |
|
|
what are the features of astroviruses?
|
ssRNA
star-shape on capsid what is the epidemiology? |
sporadic - no particular season
epidemics in young kids, peds ward, day care, nursing homes |
|
|
what biochem test is used to identify virbrio?
|
oxidase: vibrio is +
|
|
|
|
what are the 2 serotypes of cholera?
|
O1
O139 after infection with O1, is pt immune to O139? |
no, O139 can still cause disease
|
|
|
what is the best way to prevent cholera?
|
proper sewage control - infection occurs when it gets into drinking water
|
|
|
|
what is cholera cultured on? why?
|
TCBS
(thiosulfate citrate bile salt sucrose) provides them w/ a high pH environment, favoring vibrios over everything else bile salts kill off any non-GI bugs |
|
|
|
where do vibrio parahaemolyticus infections originate?
|
raw/undercooked shellfish
what are the symptoms? |
2-3d watery diarrhea, vomiting, HA, chills, low-grade fever
|
|
|
what bug is assoc. w/ washer woman's hands?
|
cholera
what blood type is most susceptible? |
O
|
|
|
what does the cholera A-B exotoxin do?
|
↑cAMP ⇒ hypersecretion of H2O
|
|
|
|
what is the result of the rice water stools seen w/ cholera?
|
severe dehydration
hypovolemic shock metabolic acidosis death |
|
|
|
which bug is assoc. w/ oysters?
|
vibrio vulnificus
what 3 types of infections are seen? |
1 - wound
2 - sepsis (pt has underlying liver problem) 3 - acute self-limiting diarrhea ALL go with oysters |
|
|
how does shiga toxin act?
|
disrupts protein synthesis
cleaves 28S rRNA of 60s subunit endothelial damage may activate macrophage apoptosis |
|
|
|
what would be seen in a microscopic exam of feces in a shigella case?
sigmoidoscopic exam? |
feces - PMNs & RBCs
sigmoid colon - shigellosis diffuse involvement of mucosa, multiple shallow ulcers amoeba - focal pattern of ulcers |
|
|
|
what is the most important prevention for shigella?
|
hand washing
|
|
|
|
how infectious is shigella?
salmonella? |
shigella is highly infectious - 200 can cause ds
salmonella is less infectious - need a high dose |
|
|
|
what differentiates shigella & salmonella from e. coli?
|
shigella and salmonella are lactose NON-fermenting
|
|
|
|
what are the sx of shigella?
|
range from moderate diarrhea to severe dysentery
initial sx: fever, cramps, vomting, watery diarrhea progression to dysentery is classic |
|
|
|
what is reiter's syndrome?
|
complication of shigella
non-specific acute inflammatory arthritis strong assoc. w/ HLA-B27 |
|
|
|
what are the 4 types of salmonella infections?
|
1 - gastroenteritis - 12-48hr incubation, sudden onset, fever, chills, cramps, diarrhea, vomiting; 2-3d duration
2 - bacteremia or septicemia w/o GI sx 3 - enteric fever 4 - carrier state |
|
|
|
what is the source of salmonella?
why is incidence increasing? |
food (animal origin) & water
changes in food processing changing consumer preferences changes in animal husbandry |
|
|
|
which cells do shigella & salmonella infect?
|
shigella - M cells, via O Ag-induced endocytosis
salmonella - M & epithelial cells |
|
|
|
what is the function of phoPQ-controlled genes?
|
allow for salmonella's intra-phagocyte survival
|
|
|
|
what lab feature identifies s. typhimurium?
|
produces H2S
black color |
|
|
|
what is seen in fecal matter w/ salmonella?
|
leukocytes present
macrophages > PMNs |
|
|
|
what 4 things are necessary for salmonella prevention?
|
clean
separate cook refrigerate |
|
