opportunistic fungal infections Flashcards
where is candida albicans found ?
found in the normal oral , gut, vaginal flora
what is the most common contaminant of sputum culture ?
candida
when candida dissementes what can it cause ?
endocardiditis
candidiemia
what are the 2 unique shapes associated with candida ?
pseudo hyphae
and budding yeast at 20 C
germ tubes at 37 C
what type of patients are more likely to suffer from disseminated candidiasis ?
neutropenic patients who are undergoing chemo
ICU patients
central line patients
TPN
IV drug users
what is the germ tube test ?
to identify candida , the yeast that grows hyphae will grow out
both hyphae and yeast on one slide ?
most likely looking at candida
what are the causes of oral thrush ?
inhaled steroid in an asthma patient
patient that is sexually active and now has thrush ?
should probably think of HIV
what are the causes of candidal over growth in the eosphagus ?
eosphagitis usually happens in HIV patients
showing a white pseudomembrane on EGD
what is the presentation of vulvovaginitis ?
itching
discharge
cottage cheese like discharge
what is the classic patient associated with vulvovaginitis ?
a patient that has just taken an antibiotic
what is the presentation of diaper rash caused by candidia ?
beefy red plaques with satellite papules
when can candida cause endocarditis ?
an immunocompromised patient who is an IV drug user
what is the treatment for each of the following :
vaginal disease / diaper rash
oral thrush
esophagitis
candidemia/endocaritis
vaginal disease / diaper rash : topical azole
oral thrush : nystatin swish and swallow, fluconazole
esophagitis : flucanozole
candidemia/endocaritis : capsofungin or amophecetrin B
what is the treatment for resistant cases of esophagitis ?
voriconazole
capsofungin
what is chronic mucocutaneous candidiasis and what is the probelm ?
mutation in the AIRE gene
T cells fail to react to the candida antigen
presents as a baby with recurrent candida infection - diaper rash , recurrent thrush
what is the main immune defense for mucosal defense ?
T cells
what are the most important cells for systemic defense ?
neutrophils , thats why cancer patients are at a higher risk for candidemia
do CMC patients get candidemia ?
no
what is the most common patient associated with aspergillus ?
must be immunocompromised
high dose chemo pts
stem cell trasnplant
what type of infections are people with chronic granulomatous disease at a higher risk for ?
catalase positive organsisms
what fungus is cigar shaped ?
the one that causes rose gardeners disease
sporothrix schenckii
what are the catalase positive organisms ?
notoriously big bubbles HASSLE
nocardia
burkh
bordatella
h pylori
aspergillus
serratia
staph
listeria
e coli
what are the lab and morphological features of aspergillus ?
catalase psoitive
monomorphic fungi
forms branching septate hyphae v shaped branches with visible septae
the tips grow spores
what are the diseases associated with aspergillus ?
aspergillosis
allergic bronchopulmonary aspergillosis
aspergilloma
hepatocellular carcinoma
what is the classic case associated with aspergillosis ?
severe lung disease
neutropenic patient
fever cough \pleuritic chest pain
hemoptysis
can dissement to any organ
what are the treatments for aspergillosis ?
caspofungin
amphotericin B
voriconazole
what ABPA, and who does it affect ?
hypersensitivty reaction to aspergillus
happens in asthma or CF patients
what are the findings associated with lymph tissue in patients who have ABPA ?
increase in Th2 CD4 cells
which then stimulated the formation of IL 4 and IL 5
which allow for the recruitment of eosinophilia
allows for IgE antibody production
what is the classic case of ABPA ?
asthma of CF patients
recurrent cough
brownish mucus plugs hemoptysis
peripheral blood eosinophilia
high IgE levels
hos is the diagnosis of ABPA made and what is the treatment ?
skin testing
treatment is steroids
what is an aspergilloma and where does it grow ?
fungus ball
grows in pre formed cavities especially after TB infections
what is the toxin cause by aspergillus and where is it found ?
aflatoxin caused by peanuts and soybeans
locally grown food
what is the main disease associated with cryptococcus neoformans ?
meningitis in immunocompromised patients
where is cryptococcus neoformans usually found ?
found in the soil and in pigeon droppings
what is the structure of cryptococcus neoformans ?
never see hyphae
only a yeast
very thick capsule
how is cryptococcus neoformans cultured and what is the staining used for it?
cultured on sabourauds agar
india ink is used and shows halos
what test is used for the identification of cryptococus neoformans ?
latex agglutination test
what is the appearance of cryptococcus neoformans once it reaches the brain ?
soap bubbles appearance
what is the risk associated with LP in cryptococcal meningitis ?
higher risk f brain herniation due to high ICP
what is the difference in presentation between bacterial meningitis and cryptococcal meningitis ?
bacterial meningitis shows symptoms almost immediatley whilst cryptococcal is indolent and happens over weeks
what is the treatment for cryptococcal meningitis ?
intra thecal therapy is used and amphocetrin b along with flucytoseine
what is the cause of mucormycosis ?
rhixopus sp
mucor sp
what type of patients are at a higher risk of mucormycosis and why ?
DKA patients , who have a medium that is high in glucose and ketoacidosis
which is idel for the enzyme ketone reductase
what is specific about the septae hyphae of aspergillus ?
acute angle branching of hyphae at 45 degrees
DKA with severe sinusitis, fever headache and eye pain ?
think of mucromycosis
how is a diagnosis of mucormycosis made ?
mucosal biopsy
how do ypu differentiate between aspergillus and mucromycosis ?
mucromycosis - broad hyphae , with irregular branching , no septations
aspergillus - narrow hyphae , v shaped branching , many septations
what is the classic scenario associated with PCP ?
diffuse interstitial ppneumonia that happens with immunocompromised ptients especially HIV patients
what does the chest x ray show in PCP ?
bilateral interstitial infiltrates
how is PCP diagnosed ?
sputum sample , BAL biopsy
cannot be cultured
sent for staining
silver stain used
first line treatment for PCP ?
TMP SMX
dapsone
pentamidine
what is the prophylaxis of PCP ?
TMP-SMX when CD4 cells are below 200 cells
