gram + rods Flashcards
Bacillus Anthracis
virulence factors
Anthrax toxin and capsule
3 types of anthracis
pulmonary, cutaneous, GI
Bacillus Anthracis
transmission
Spores are inhaled, injected, or ingested
MC route is cutaneous but can also be GI or inhalation
Spores hide in bristles, wool
NOT transferred from human to human
comet tail appearance
Bacillus Anthracis
what does Bacillus Cereus cause
gastroenteritis/food poisoning
Spores in soil & food; germinate when kept warm (think rice)
Bacillus Cereus
clostridium is aerobic/anaerobic
anaerobic
Tennis racket shaped with terminal spore at end
c tetani
C. Tetani pathogenesis is _____ mediated
Exotoxin
dx C. Tetani
clinical
early clinical findings of C tetani
Early: recent wound, no vaccine, irritability, restlessness, HA, low grade fever
c tetani triad
Triad: lockjaw/trismus, opisthotonos, ascending spasic paralysis
Trismus- contraction of jaw muscles and closed mouth, risus sardonicus (characteristic grimace)
Opisthotonos- arching of back
c tetani trmt
Tetanus toxoid (formaldehyde treated toxin) every 10 yrs- DTaP
Dirty wound and over 5 yrs since last booster? → immunization
Not dirty wound and booster not given in 10 yrs → booster without tetanus Ig/tetanus antitoxin
Passive active immunity
toxoid vaccine?
used when bacterial toxin is main cause of illness. Treat them with formalin (formaldehyde + sterilized H2O) ex: diphtheria and tetanus
Only fatal food poisoning
c botulism
Canned foods, honey, cosmetic use
c botulism
c botulism transmission
Spores from soil contaminate veggies and meats
Spores get into canned foods that we ingest
c botulism paralysis
descending flaccid
c botulism fever?
no
c botulism dx
clinical
2 forms of c botulism
wound and infant
wound botulism?
spores contaminate the wound and make toxins at the site; associated with drug abuse and skin popping in black tar heroin
infant botulism?
organism grows in the gut and makes toxins there (half of cases are these)
where is C. Perfringens in on the body
normal flora of colon and vagina
C. Perfringens 2 types
gas gangrene and food poisoning
Transmission gas gangrene/myonecrosis c perfrinogens
Get in through a traumatic wound: war, automobile, septic abortions
Pathogenesis gas gangrene/myonecrosis c perfrinogens
Alpha toxin/lecithinase causes direct damage to cell membranes and make gas in the tissues
Other toxins cause pore forming necrosis
transmission food poisoning perfrinogens
Ingest heat resistant spores in meat and poultry
Changes intestinal membrane permeability
Fluid and ion loss from superantigen
Pathogenesis food poisoning perfrinogens
Enterotoxin acts in the SI to cause watery diarrhea
Trmt gas gangrene/myonecrosis
atb, surgery
trmt food poisoning
NO ATB, rehydration
Encapsulated with D glutamate
Bacillus Anthracis
bacillus anthrax is motile or nonmotile
nonmotile
edema and lethal factor are part of
bacillus anthrax
edema factor?
adenylate cyclase → inc in cAMP → edema
lethal factor?
activates MAPk → necrosis
protective Ag of balillus anthrax
B subunit
bacillus anthrax is _____ hemolytic
gamma
Bacillus Cereus is aerobic/anaerobic
both
Bacillus Cereus is motile/nonmotile
motile
Enterotoxins
Type 1/emetic:
bacillus cereus
fried rice, potato, pasta, cheese
enterotoxins Type 2 (diarrheal): bacillus cereus
meat, milk, veggies, fish
No spores in smears
bacillus anthrax
Tetanolysin is part of ____ and does this
c tetani; lysis tissue around infection
Tetanus toxin (tetanospasmin)is part of ____ and does this
c tetani; one antigenic form so we can have the toxoid vaccine
“Skin popping” in drug addicts
c tetani and wound botulism
is c tetani transmitted person to person
no
____ and ____ favor spore germination in c tetani
Necrotic tissue and poor blood supply
MC nosocomial (HA) cause of diarrhea
C. Difficile
Leading infectious cause of GI associated deaths in US
C. Difficile
c diff is aerobic or anaerobic
anaerobic
stool toxin levels correlate with disease severity
c diff
what toxins does c diff make
Make toxins A and B
c diff sx
diarrhea → colitis
Pseudomembranous colitis?
yellow plaque like lesions from exotoxin cause enterocytes to die
what disease is pseudomembranous colitis in
c diff
what is c diff resistnt to
Resistant to broad spectrum ATB
where does c diff colonize
LI
when might someone get c diffe
Occurs after long term ATB therapy
human to human transmission in c diff?
yes
Toxin A- enterotoxin
in c diff
Causes inflammation and activates neutrophils
Promotes neutrophil chemotaxis
Toxin B- cytotoxin
in c diff
Need for virulence
10* more potent than toxin A
Also promotes neutrophil chemotaxis (she said this one recruits neutrophils)
Inc risk if you have IL8 gene promoter
c diff
best at protecting against C. Diff
Serum antitoxin antibodies
c diff prevention
No vaccine
Only take ATB when necessary
Control infections by washing hands and such
Probiotics
Club shaped V or L shaped
Corynebacterium Diphtheria and listeria monocytogenes
Corynebacterium Diphtheria is motile or nonmotile
nonmotile
Corynebacterium Diphtheria
transmission
Preventable with DTaP
Humans are only natural host
Airborne from respiratory tract
dx Corynebacterium Diphtheria
Pseudomembrane over tonsils and throat
Fever, ST, cervical adenopathy
Corynebacterium Diphtheria
complications
Airway obstruction
Myocarditis
Nerve weakness or paralysis
Corynebacterium Diphtheria
toxins
Diphtheria toxin with A (alpha) domain and B (binding) domain
Corynebacterium Diphtheria
host response
Local inflammation in the throat- pseudomembrane
Ab that neutralizes exotoxin activity
Botox is exotoxin
A
Absorbed in the gut and carried by blood to peripheral nerve synapses where it blocks the release of ACh
c botulism
Polypeptide encoded by lysogenic phage
c botulism
8 immunologic toxins (only 2 in tetanus)- MC are A, B, E
c botulism
what doess Listeria Monocytogenes
cause
Cause meningitis, sepsis, and gastroenteritis
Listeria Monocytogenes
is ____ hemolysis
Beta
“Cold enhancement”
Listeria Monocytogenes
Listeria Monocytogenes is motile/nonmotile
motile- flagella cause tumbling mvmt
Infection during pregnancy can be a big issue
Listeria Monocytogenes
Febrile gastroenteritis is caused by ______ in Listeria Monocytogenes
contaminated dairy products, undercooked meats, and ready to eat foods
Listeria Monocytogenes
transmission
In animals, plants, soil
Fecal oral
Bacteria colonize GI and GU which can cross the placenta during pregnancy
Bacteremia can occur
internalin, listeriolysin, and ActA protein are in _____
Listeria Monocytogenes
internalin?
surface protein that allows adhesin and invasion
listeriolysin?
listeria gets in cell and destroys phagolysosome; cell mediated suppression predisposes someone to get Listeria
ActA protein?
actin rocket allow listeria to shoot around the cell
“Gram variable”- gram + cell wall but wall is so thin
Gardnerella Vaginalis
Older organisms lose purple color
Gardnerella Vaginalis
MC vaginal infection of sexually active women
Gardnerella Vaginalis
Gardnerella Vaginalis causes this
bacterial vaginosis
Causes fishy odor and white/gray vaginal discharge
bacterial vaginosis
inflammatory changes in bacterial vaginosis?
no
Gardnerella Vaginalis is NOT transmitted by
sexual activity
Dysbiosis
lactobacillus on normal vaginal flora are replaced by Gardnerella
Gardnerella Vaginalis dx
Clue cells- covered with bacteria
+ Whiff test- treating discharge with 10% KOH causes fishy odor
Vaginal discharge has pH over 4.5
Gardnerella Vaginalis trmt
Metronidazole
Don’t treat sexual partners
No vaccine
Have good GU hygiene, use latex condoms, limit sexual partners