Basic Bacteriology II Flashcards
obligate intracellular
rickettsia
chlamydia
coxiella
facultative intracellular
salmonella neisseria brucella mycobacterium listeria franscisella legionella yersinia pestis
encapsulated bacteria
strep pneumo h. flu type B neisseria meningitidis E. coli salmonella klebsiella pneumonia group B strep
anti-phagocytic virulence factor
-opsonized and cleared by spleen
asplenic patient
need to vaccinate - strep pneumo, h. flu, neisseria meningitidis
cannot opsonize and clear encapsulated bacteria
vaccines to asplenic patient
pneumovax - PCV and PPSV
h. flu type B - conjugate vac
meningococcal vaccine - conjugate vac
urease positive organisms
cryptococcus h. pylori proteus ureaplasma nocardia klebsiella staph epidermidis staph saprophyticus
catalase positive organisms
nocardia pseudomonas listeria aspergillus candida E. coli staph serratia
bacteria form yellow sulfur granules
actinomyces israelii
-filaments of bacteria
bacteria form yellow pigment
staph aureus - gold
bacteria form blue-green pigment
pseudomonas aeruginosa
bacteria produce red pigment
serratia marcescens
protein A
bind Fc region IgG - prevent opsonin and phago
staph aureus
IgA protease
to colonize resp tract
strep pneumo
h. flu type B
neisseria
M protein
group A strep - prevent phago
molecular mimicry - autoimmunity in rheumatic fever
type III secretion system
injectisome aka
needle like appendage - delivery of toxins from gram - to host
pseudomonas, salmonella, shigella, e. coli
exotoxin
secreted from cell polypeptide gene in plasmid or bacteriophage high toxicity vaccines are toxoids
ex/ tetanus, botulism, diptheria
endotoxin
outer cell membrane gram - bacteria LPS genes in bacterial chromsome low toxicity induce TNF, IL1, IL6 no vaccines available
ex. meningococcemia - sepsis gram - rods
cornybacterium diptheria exotoxin
diptheria toxin
-inactivate EF-2
pharyngitis with pseudomonas in throat and severe lymphadenopathy - bull neck
pseudomonas aeruginosa exotoxin
exotoxin A
-inactivate EF-2
host cell death
shigella exotoxin
shigella toxin (ST)
inactivate 60S ribosome - remove adenine from rRNA
GI mucosa damage - dysentery
enhanced cytokine release - HUS
EHEC exotoxin
shiga-like toxin (SLT)
inactivate 60S ribosome - remove adenine from rRNA
cytokine release > HUS (prototype O157:H7)
does not invade host cells
ETEC exotoxin
heat-labile - activate adenylate cyclase (cAMP)
- increased cAMP
- increased Cl secretion and H2O efflux
- watery diarrhea
heat-stabile - activate guanylate cyclase (cGMP)
- increased cGMP
- decreased reabsorption NaCl and H2O
- watery diarrhea
heat labile vs. heat stabile toxin
both exotoxin from ETEC
- heat-labile - adenylate cyclase - cAMP - Cl
- heat stabile - guanylate cyclase - cGMP - NaCl
bacillus anthracis exotoxin
edema toxin
- mimic adenylate cyclase - increased cAMP
- edematous border of black eschar in cutaneous anthrax
vibrio cholera exotoxin
cholera toxin
overactive adenylate cyclase - increased cAMP release
- permanent activated Gs
- increased Cl secretion and H2O efflux
rice water diarrhea
bordetella pertussis exotoxin
pertussis toxin
- overactive adenylate cyclase - increased cAMP
- disabling Gi
whooping cough
bordetella pertussis
clostridium tetani exotoxin
tetanospasmin
-cleave SNARE - for NT release via vesicle fusion
prevent release of GABA and glycine (inhibitory)
- NT from renshaw cells in spinal cord
- spasticity, risus sardonicus, lockjaw
clostridium botulinum exotoxin
botulinum toxin
-cleave SNARE - for NT release via vesicle fusion
flaccid paralysis, floppy baby
-toxin prevent stimulatory ACh signals at NMJ
exotoxin ADP ribosylating A-B toxin
B - binding - to host cell surface receptor - allows endocytosis
A - active component - attaches ADP ribosyl to disrupt host cell proteins
clostridium perringes exotoxin
alpha toxin
phospholipase - degrades tissue and cell membranes
degrades phospholipids - myonecrosis (gas gangrene) and hemolysis (double zone on blood agar)
strep pyogenes exotoxin
streptolysin O
protein - degrade cell membranes
lyses RBCs - contribute to beta-hemolysis
Abs - ASO - diagnosis of rheumatic fever
diagnose strep pyogenes
ASO titer - antibody to streptolysin O
staph aureus and toxic shock exotoxin
TSST-1
-superantigen
bind MHC II and TCR - outside of Ag binding site
- overwhelming release of IL1, IL2, IFN-gamma, TNF-a
- shock
toxic shock syndrome
staph aureus exotoxins
TSST-1 - toxic shock syndrome
exfoliative toxin - scalded skin syndrome
enterotoxin - food poisoning
strep pyogenes exotoxin
exotoin A
-superantigen
bind MHC II and TCR - outside of Ag binding site
- overwhelming release of IL1, IL2, IFN-gamma, TNF-a
- shock
can also cause toxic shock syndrome
LPS
in outer membrane of gram negative bacteria
-lipid A
activate macros - IL1, TNFa, nitric oxide
activate complement - C3a, C5a
activate tissue factor - coag cascade > DIC
transformation
take up naked DNA from environment
strep pneumo, h flu type B, neisseria
conjugation
sex pilus on F+ contacts F- bacteria
single strand of plasmid DNA transferred across conjugal bridge
high frequency recombination
Hfr
F + plasmid - incorporated into bacterial DNA
-replication of incorporated plasmid DNA
transposition
segment of DNA - excision and reintegration from one location of DNA to plasmid and vice versa
vanA
vanco resistant enterococcus > staph aureus
transfer of plasmid genetics
transduction generalized
lytic phage infect bacteria - cleave bacterial DNA
-parts of bacterial DNA into viral capsid
phage then infects another bacterial cell
packaging event
transduction specialized
lysogenic phage infect bacteria
- viral DIA into bacterial chromosome
- phage DNA excised - flanking bacterial genes excised with it
- DNA packed into phage viral capsid
excision event
