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56 Cards in this Set
- Front
- Back
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what type of bugs have a periplasm & why is it important
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g(-), its the location of b-lactamase
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endotoxin/LPS is found in what type of bugs
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g(-)
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5 bacteria that secrete enterotoxin
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vibrio cholera
ETEC staph aureus salmonella & shigella |
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teichoic acid is found in which bugs
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g(+)
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bugs that don't gram stain
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treponema, too thin
rickettsia, intracellular mycobacteria, high lipid content mycoplasma, no cell wall legionella, intracellular chlamydia, intracellular & lacks muramic acid |
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stain for treponemes
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darkfield microscopy & fluorescent Ab staining
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stain for legionella
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silver
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giemsa stain
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borrelia
plasmodium trypanosomes chlamydia |
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PAS stain
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stains glycogen & mucopolysacchrides
used to Dx whipple's dx bc it stains tropheryme whippelii |
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ziehl-neelsen stain
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acid fast organisms
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india ink
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cryptococcus neoformans
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silver stain
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fungi & legionella
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H. influenza culture
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chocolate agar w. factors V & X
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N. gonorrhea culture
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thayer-martin agar
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b. pertussis culture
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bordet gengou (potato) agar
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M. tuberculosis culture
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lowenstein jensen agar
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m. pneumonia culture
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eaton's agar
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lactose fermenting enterics culture
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macconkey's agar
e. coli also grows on eosin-methylene blue |
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legionella culture
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charcoal yeast extract agar buffered w. cysteine
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fungi culture
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sabouraud's agar
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quellong rxn & associated bugs (some killers have nice shiny bodies)
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capsule swelling in encapsulated bugs
strep pneumonia klebsiella h. influenza b neisseria meningitis salmonella group b strep |
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SHiN bugs & 3 special characteristics
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strep pneumoia
h. influenza b neisseria meningitis make IgA protease cause meningitis undergo transformation |
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obligated anaerobes (can't breath air)
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clostridium
bacteroides actinomyces |
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why are aminoglycosides ineffective against obligated anaerobes
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bc these drugs require O2 to enter the bacterial cell
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obligated intracellular bugs (really cold)
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rickettsia
chlamydia can't make their own atp |
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some nasty bugs may live facultatively
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salmonella
neisseria brucella mycobacterium listeria francisella legionella |
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function of capsule
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antiphagocytic virulence factor
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urease positive bugs
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proteus
klebsiella h. pylori ureaplasma |
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actinomyces pigment
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yellow sulfur granules composed of a mass of filaments & formed in pus
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s. aureus pigment
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yellow
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pseudomonas aeruginosa pigment
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blue green
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serratia marcescens pigment
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red
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3 bacterial virulence factors
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protein a = s. aureus, binds Fc region to prevent opsonization & phagocytosis
IgA protease = SHiN, cleaves IgA so they can colonize respiratory mucosa m-protein = group a strep, helps prevent phagocytosis |
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is endotoxin secreted? exotoxin?
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endo no
exo yes |
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location for endotoxin & exotoxin coding
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endo = bacterial chromosome
exo = plasmid or bacteriophage |
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toxicity of endo & exo toxin
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endo = low
exo = high |
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antigenicity of endo & exo toxin
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endo = poor
exo = high titer ab called antitoxins |
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clinical effects & MOA of endotoxin
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fever & shock via TNF & IL1
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11 bugs making exotoxin & the type
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superantigens:
s. aureus s. pyogenes ADP ribosylating AB toxins: c. diphtheriae vibrio cholerae e. coli pertussis other: c. perfringens c. tetani c. botulinum anthrax shigella s. pyogens |
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4 cAMP inducers & how
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vibrio cholera, permanently activates Gs
pertussis permanently disables Gi e. coli, ADP ribosylation (v. cholera also) anthrax, edema factor a bacterial adenylate cyclase |
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superantigens
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bind directly to MHC 2 & TCR simultaneously, activating large number of t-cells to stimulate IFN-gamma & IL2 release
TSST1 of s. aureus erythrogenic toxin of s. pyogens |
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ADP ribosylating AB toxins
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interfere w. host cell function
B = binds receptor on host cell surface enabling endocytosis A = attaches ADP-ribosyl to host cell protein, altering protein function c. diphtheriae v. cholerae e. coli pertussis |
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effect of c. diphtheriae toxin
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inactivates elongation factor 2, which can be lethal bc it effects heart & nerve cells
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effect of v. cholerae toxin
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ADP ribosylation of Gs stimulates adenyly cyclase causing increased pumping of Cl- into gut & decreased Na absorption so H2O moves into the gut lumen causing voluminous rice water diarrhea
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effect of ETEC toxin
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heat labile toxin stimulates adenylate cyclase
heat stable toxin stimulates guanylate cyclase both cause watery diarrhea |
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effect of pertussis toxin
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inhibitiong of Gi alpha protein causes whooping cough
inhibition of chemokine receptor causes lymphocytosis |
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effect of c. perfringens toxin
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alpha toxin, a lecithinase that acts as a phospholipase to cleave cell membranes causing gas gangrene & a double zone of hemolysis on blood agar
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effect of c. tetani toxin
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blocks release of GABA & glycine causing spastic paralysis
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effect of botulinum toxin
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blocks release of Ach causing floppy paralysis
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effect of shiga toxin
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cleaves host rRNA & enhances cytokine release causing HUS
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8 toxins released by s. aureus & their effects
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alpha = hemolysis
beta = sphingomyelinase proteins A, B & C of gamma toxin = A+B is hemolysis B + C is leukocidin hemolysin = hemolysis leukocidin = leukocyte destruction enterotoxin A-E = vomiting & diarrhea shortly after ingesting preformed toxin TSST1 = toxic shock syndrome via cytokine release epidermolytic/exfoliative = scalded skin syndrome from epithelial cell lysis |
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3 toxins released by s. pyogens & their effects
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streptolysin o = hemolysis, oxygen liable
streptolysin s = hemolysis, oxygen stable erythrogenic/pyrogenic toxin = skin rash & fever of scarlet fever |
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3 spore forming bugs & 3 characteristics they share
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coxiella burnetti
bacillus species clostridum perfringens & botulinum contain dipicolinic acid no metabolic activity very resistant to destruction, need to autoclave them |
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antibiotic resistance genes are carried on what
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plasmid
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toxins encoded on lysogenic phages (a, b, c, d, e)
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shiga like toxin
botulinum cholera diphtheria erythogenic toxin of s. pyogens |
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3 acute phase cytokines
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IL1
IL6 TNF |
