Shared Flashcard Set

Details

Intro
ex3 - micro
22
Medical
Professional
09/27/2011

Additional Medical Flashcards

 


 

Cards

Term
some fxns of bacterial growth that make them difficult to access with drugs
Definition

they can grow in large aggregates, like a big mass

 

can have thick cell walls made of peptidoglycan

Term
why is hyphae?
Definition
the mold form of fungi
Term
advantage of bacteria's ribosome?
Definition
it's 70S which is distinct from human, therefore, specific ribsome targetting therapies will be specific to the bacteria
Term
a major acid-fast bacteria of concern?
Definition
mycobac TB
Term
major shape clue dx of s. pneumoniae?
Definition
the diploccus shape
Term
what shape are vibrio bacteria?
Definition
curved rods
Term
what is a characterisic of all bacillus and clostridium members?
Definition

they are all spore forming

 

spores are very hard to destroy

Term
explain the cell wall
Definition

it is what gets gram stained.  a positive result has a 3D cell wall that is very thicl and heavily crosslinked.  negative is 2D and is sandwiched by 2 lipid bilayers.

 

the key to killing the bacteria is using B-lactam (penecillin, cephalosporin) to interrupt the crosslinking of the bacterial wall.  This will create permeability

Term
why gram neg cells stain negative.
Definition
because the decolorization washes away lipids and the GM- bacs are covered by a second lipid bilayer
Term
how endotoxin works
Definition

GM- bacteria have a complex on their wall that includes Lipid A.  This can get hydrolyzed or release when they die

 

this lipid is pyrogenic and causes fever -> shock -> multiple organ failure -> disseminated intravascular coagulation (blood clotting) -> death

Term
use of fimbria and pilli?
Definition

they have adhesive properties

 

because the fimbria of e. coli are specific to the epithelium of the urethra, and because of the proximity of the anus to it, UTI are often started this way

Term
bacterial capsule defense mechanisms
Definition

can prevent drying, therefore the can live outside of the cells for an extended time

 

they can protect the cell against antimicrobial agents/phagocytosis (the #1 reason they are so dangerous)

 

an aside - they are immuno and antigenic so they are useful in subtyping bacteria

 

vaccines have been made available because they are specific to the antigens on the polysaccharide capsule and make OPSONIZING ABs of several dangerous bacteria making them more likely to be phagocytosed

 

Mycolic acids are long hydrocarbon chains and when capsules are made up of these, they're practically wax (they acid fast stain)

Term
antibiotics targeting bacterial ribosome protein synthesis?
Definition
aminoglycosides, tetracyclines, macrolides
Term
antibiotic targets of bacterial DNA synthesis?
Definition
quinolones, ciprofloxacin, sulfonamides, trimethoprim
Term
what is a risk factor for developing a fungal infection?
Definition
even though they're rare, the use of immunosupressants can increase the risk
Term
an important distinction between hyphae?
Definition

coenocystic (hollow and multinucleated)

 

septate (individual cells separated by cell wall)

Term

Mycelia: 

Definition
masses of intertwining hyphae with or without branching.
Term

Conidia: 

Definition

Hyphae growing above a surface may produce conidia (asexual reproductive elements often referred to as spores).


airborne spread

Term

properties of Entamoebahistolytica

Definition
vProperties:  2 stages:
vAmeboid or trophozoite (motile, actively feeding stage):  In lesions and diarrheal stools.
vCyst (nonmotile, quiescent infective stage):
v
Term
what is a nucleocapsid? what shapes can it be?
Definition
it is when the protein capside and nucleic acid combine.  the shapes can be icosahedral and helical
Term
what implications does having a lipid envelope have on a virus?
Definition
it can make it suspectible to detergents, drying, heat, or other chemical treatments
Term
what is a provirus
Definition
a viral chromosome that has been constructed by creating cDNA from viral RNA using reverse transcriptase which is then transported to the nucleus.  the cDNA will contain many errors as reverse transcriptase does not contain proof reading abilties
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