Opportunistic Infections Flashcards
cryptococcus
fungi that can cause meningitis
What do you use to stain cryptococcus? What does it show?
use India Ink stain
will show “halo” due to cyptococcus capsule
What does opening pressure of LP tell you?
that there is a pathogenic infection
What is normal WBC count of CSF?
normal is 0
What is another buzz word for cryptococcus?
budding yeast
If you have lymphopenia what are you suspectible to
fungal and viral infections
If you have neutropenia what are you suspectible to
bacterial infections
How is cryptococcus transmitted?
normally found in soil / nature
transmitted through inhalation
Where is cryptococcus tropic to?
the CNS
What is the treatment for cryptococcus?
amphoterine B + flucytosine
then, follow up with fluconazole
How does amphoterine B works?
disrupts the cell membrane
2 virulence factors of cryptococcus
1) thick capsule that prevents phagocytosis
2) melanin in cell wall that acts as armor
What type of virus is Hep B?
dsDNA virus with envelope
What are the 3 types of antigens we test for with HepB?
surface
E
core
How is HBV transmitted?
through blood + vertical transmission + sexual contact
What does Aspergillus most commonly infect?
the lungs
What are the 2 paths of HBV infection?
1) clear infection (over 90% of people)
2) chronic infection
What is a hallmark of chronic HBV infection?
HbsAG is positive with antibodies
HbeAG is negative
cccDNA
covalently closed DNA
even if you clear HBV, the DNA can still persist as cccDNA fragments in hepatocytes
this makes reactivation of HBV possible
Is there a cure for Hep B?
no
What are the 5 most common types of herpes viruses?
HSV (herpes)
CMV
EBV (mono)
VZV (chicken pox)
HHV-8 or KSHV
What does HHV-8 / KSHV cause?
Kaposi sarcoma
remember this is an AIDS-defining illness
What are all herpes viruses?
dsDNA
What is a hallmark that rash is caused by VZV?
dermatomal, burning rash
disseminated Zooster
like shingles but is more widepread
also reactivated VZV
Abnormalities in opsonization and reticuloendothelial system (RES) are associated with what type of opportunistic infection?
encapsulated organisms (SHIN)
Granulocyte or neutrophil abnormalities are associated with what type of opportunistic infection?
catalase-positive organisms
Give 2 diseases that represent abnormalities in opsonization and RES?
lupus
asplenia
B-lymphocytes abnormalities are associated with what type of opportunistic infection?
encapsulated organisms
B-lymphocytes produce what?
IgG and IgA
remember that B-cells produce antibodies
T-lymphocyte abnormalities are associated with what type of opportunistic infection?
fungi and yeasts, parasites, viruses, and mycobacterium
T-lymphocyte abnormalities include ….
HIV/AIDS
immunocompromised states (chemotherapy, transplant, etc)
List 4 ways fungi are different than bacteria
1) Nuclear membrane
2) more than one chromosome
3) mitochondria + ER
4) cell wall is made up of mannans, glucan and chitin
What are most fungi?
obligate aerobes
Do fungi or bacteria have sterols in their membrane?
only fungi
3 examples of blood borne pathogens
hep C
hep B
HIV
examples of yeast
candida and cryptococcus
features of yeast
round
reproduce by asexual budding
can produce pseudohyphae (two elongated yeast together which look like they are hyphenated but not!)
example of a mold
Aspergillus
Another name for molds
filamentous fungi
features of molds
branching structure
multicellular forms composed of tubular structures called hyphae
features of dimorphic fungi
can grow in either yeast or mycelium form
thermally dimorphic fungi
grow in mold form at normal temperatures, but when incubated they convert to yeast-like forms
