Micro: Quick Facts Flashcards
ferment glucose with acid production
Shigella
E. coli
Salmonella
Gram ( - ) facultative anaerobic rods
Shigella
E. coli
Salmonella
reduce nitrates to nitrite
Shigella
E. coli
Salmonella
oxidase negative
Shigella
E. coli
Salmonella
motile
E. coli
Salmonella
Vibrio
H. pylori
non-motile
Shigella
H antigen
flagella
Shigella, E. coli, Salmonella
O antigen
LPS
Shigella, E. coli, Salmonella, Vibrio cholerae
non-lactose fermenting
Shigella
Salmonella
Daycare centers
Shigella
invade epithelial M cells
Shigella
Salmonella enteritidis and enterica
spread to adjacent cells via membrane bound protrusions
Shigella
formins
cellular actin polymerization proteins needed for membrane bound protrusion
Shigella
reactive arthritis
arthritis, urethritis, conjunctivitis
more common in HLAB27
Shigella, Salmonella enteritidis, Campylobacter jejuni, Yersinia enterocolitica
hemolytic uremic sndrome
microangiopathic hemolytic anemia (SCHISTOCYTES), thrombocytopenia
EHEC: main cause of HUS in kids
Shigella (less common)
AKI with dialysis required in over half of pts
neuro Sx: seizures, somnolence
Shiga toxin
AB toxin
Shigella dysenteriae
E. coli that can’t ferment sorbitol
0157: H7 EHEC
hamburgers
EHEC
contaminated vegetables/milk
EHEC
hemorrhagic colitis
EHEC
Shiga-like toxin
AB toxin
EHEC
PAI
EHEC
Type III secretion system
EHEC
Salmonella enteritidis
H. pylori
Locus of enterocyte effacement (LEE)
EHEC, EPEC 1. PAI 2. type III secretion delivers E. coli receptor to host cell 3. pedestal formation for attachment 4. attaching and effacement lesions responsible for diarrhea
AB toxin
EHEC, Shigella
B: binds toxin to its receptor on cell
A: enters cytosol and cleaves adenine residue from the 28S rRNA of 60S ribosomal subunit, halts protein synthesis and causes death
Sorbitol MacConkey
white: 0157:H7 EHEC
red/pink (ferments sorbitol): other EHEC and E. coli
infectious diarrhea that normally only req. supportive care
EHEC Campylobacter jejuni Yersinia entercolitica Bacillus cereus S. aureus
antidiarrheals CI
EHEC
increase risk of systemic complications
antibiotics CI
EHEC
not beneficial and may induce HUS (Shiga toxin release)
produces H2S
Salmonella
poultry and eggs
Salmonella enteritidis Campylobacter jejuni (chicken)
dairy
Salmonella enteritidis
pet turtles and lizards
Salmonella enteritidis
endovascular infection
Salmonella enteritidis
osteomyelitis
Salmonella enteritidis
predilection for aortic plaques and bone prostheses
Salmonella enteritidis
South-central Asia
Salmonella enterica (typhoid)
Central/South America
Shigella dysenteriae
poor access to sanitation
Salmonella enterica
GI tract perforation
Salmonella enterica
hypertrophy of Peyer’s patches
Salmonella enterica
chronic carriage in biliary tract
Salmonella enterica
area with high rate of fluoroquinolone (ciprofloxacin) resistance
South Asia
rose spots
faint salmon colored macules on trunk/abdomen
Salmonella enterica
hepatosplenomegaly
Salmonella enterica
traveler’s diarrhea
ETEC
EAEC
Campylobacter jejuni
spiral shaped Gram ( - )
Campylobacter jejuni
unpasteurized milk
Campylobacter jejuni
Guillian Barre syndrome
molecular mimicry: Ab to C. jejuni LPS cross react with peripheral and central nervous system gangliosides
Campylobacter jejuni
erythema nodosum
Campylobacter jejuni
Yersinia enterocolitica
Europe
Yersinia enterocolitica
pork
Yersinia enterocolitica
pet feces
Yersinia enterocolitica
raw milk
Yersinia enterocolitica
pseudoappendicitis
Yersinia enterocolitica
pery patch and mesenteric lymph node hyperplasia
Yersinia enterocolitica
pharyngitis
Yersinia enterocolitica
bipolar staining
Yersinia enterocolitica
spore
Clostridium species
Bacillus cereus
extotoxin A (enterotoxin)
Clostridium difficile
- glucosylation of small GTPases
- stimulate monocytes/macrophages to release IL-8: attracts neutrophils; disruption epithelial tight junctions
- disrupts colonic mucosal cell adherence to colonic basement membrane and damages villous tips; inflammation leads to fluid secretion
exotoxin B (cytotoxin)
Clostridium difficile
- glucosylation of small GTPases
- stimulate monocytes/macrophages to release IL-8: attracts neutrophils; disruption epithelial tight junctions
- depolymerization of actin, resulting in loss of cytoskeletal integrity, apoptosis and death of enterocytes
leukocytosis
Clostridium difficile
pseudomembranous colitis
Clostridium difficile
psuedomembranes: adherent layer of inflammatory cells and debris at site of colonic muscle injury
fulminant colitis
Clostridium difficile severe disease (abdominal pain, distention, fever, hypovolemia)
toxic megacolon
Clostridium difficile
colon dilation greater than 7cm with severe systemic toxicity
NAP-1/027
Clostridium difficile
hypervirulent strain: more severe disease, lower cure rate, higher rate of relapse
lacks tcdC
ceftriaxone, cirpo or azithromycin
Shigella Typhoid fever (S. enterica)
NOT ceftriaxone
Campylobacter
Vibrio cholerae (also erythromycin, tetracycline)
fluoroquinolones (cipro)
Salmonella enteritidis
metronidazole
C. diff or botulinum or tetani Bacteroides fragilis (or carbapenams; beta lactam with beta lactamse inhibitor)
vancomycin
C. diff
fidaxomycin
C. diff
fecal transplants
C. diff
heat labile toxin (LT)
ETEC
similar to Cholera toxin
stimulates AC increasing cAMP:
1. secretion of Chloride from intestinal cell
2. inhibition of sodium chloride at the villous tips
water secretion into lumen follows
heat stable toxin (ST)
ETEC
activates enterocyte cGMP
1. chloride secretion from intestinal cells
2. inhibition of sodium chloride absorption at villous tips
water secretion into lumen follows
oxidase positive
Vibrio
saltwater, warm climate
Vibrio
natural and manmade disasters
Vibrio cholerae
Asia, Africa, S. America, Indian subcontinent
Vibrio cholerae
shellfish
Vibrio cholerae
O1 and O139
Vibrio cholerae
responsible for epidemic and pandemic cholera
AB toxin (cholera toxin)
Vibrio cholerae
5 B subunits: binds ganglioside receptor on surface of enterocyte
A subunit: cytosol: catalyzes addition of ADP-ribose to Gs: overproduction of cAMP, PKA: phosphorylates ion transporters in cell membrane: loss of water and ions from cell into lumen
rice water stools
Vibrio cholerae
stools with flecks of mucus, smells fishy
acidosis and hypokalemia
Vibrio cholerae
MacConkey agar
Vibrio cholerae, Shigella, Salmonella: non-lactose fermenting
colorless colonies
E. coli: red/pink
thiosulfate citrate bile sucrose (TCBS) agar
Vibrio cholerae
taurocholate tellurite gelatin agar (TTGA)
Vibrio cholerae
needs aggressive volume repletion
Vibrio cholerae, parahaemolyticus
Japan
Vibrio parahemolyticus
doxycycline
Vibrio parahaemolyticus
Vibrio vulnificus: plus Cefotaxime/Ceftriaxone
bullous skin lesion
Vibrio vulnificus
fried rice
Bacillus cereus
preformed toxin
Bacillus cereus
S. aureus
superantigen
S. aureus
stimulate IL-1/2 release
potato salad
S. aureus
lack SOD and catalase
anaerobes
abscesses
anaerobes
polymicrobial infections
often anaerobes
capsule
bacteroides fragilis
UPEC
E. coli that causes neonatal meningitis
abscesses below the diaphragm
bacteriodes fragilis
lung abscesses
bacteriodes fragilis
Prevotella melaningogenica
pelvic or peri-rectal abscess
bacteriodes fragilis
resistant to penicillin
susceptible to carbapenems, combination beta lactam and beta lactamse inhibitor
Bacteriodes fragilis
disease above the diaphragm
Prevotella melaninogenica
oral/peridontal abscess
Prevotella melaninogenica
chronic otitis, sinusitis
Prevotella melaninogenica
boxcar
C. perfringens
gas gangrene
C. perfringens
psych inpatient facilities outbreaks
C. perfringens
alpha toxin
C. perfringens
AB neurotoxin
C. tetani
- enters NM junction and is transported by motor neurons to ganglia
- binds irreversibly to ganglioside receptors and blocks release of inhibitory NT (glycine and GABA) by cleaving SNARE
trimus
lockjaw
C. tetani
risus sardonicus
grimace
C. tetani
opisthotonos
pronounced arching of back due to spasm of extensor muscles
C. tetani
HTIG
human tetanus immune globulin
neutralizes toxin
C. tetani
home canned foods
C. botulinum
fish
C. botulinum
raw honey
C. botulinum
inhaled spores in carpet
C. botulinum
most potent AB toxin
C. botulinum
8 (A-H) antigenic types
cleave SNARE proteins and prevent release of ACh at NM junction
dysphasia and blurred vision
C. botulinum
symmetric descending flaccid paralysis
C. botulinum
spastic paralysis
C. tetani
floppy baby syndrome
C. botulinum
horse anti-toxin
C. botulinum
for those over 1 year of age
mechanical ventilation
C. botulinum
penicillin
C. botulinum or tetani
metronidazole alternate
VacA
H. pylori
vaculolating cytotoxin
slender, curved G (-) rod
H. pylori
microaerophilic
H. pylori
PAI
H. pylori
encoding type III secretion system
Cag
H. pylori
rearranges cytoskeleton
urease
H. pylori
K antigen
capsule
UPEC
P fimbriae (PAP pili)
UPEC
K1 antigen
capsule
E. coli neonatal meningitis
mucinase
V. cholerae
dissolves glycoprotein covering intestinal wall allowing adherence to cells of brush border
cardiac and renal failure
V. cholerae
wound infections
when might they become severe?
Vibrio parahaemolyticus and vulnificus
liver disease, DM, alcohol, RA, etc.
diarrheal syndrome
Bacillus cereus: diarrheal enterotoxin
abdominal cramps, copious diarrhea 8-16 hours after ingestion, resolves within 24 hrs
vomiting RARE
emetic syndrome
Bacillus cereus: CEREULIDE (emetic toxin): heat stable
abdominal cramps, N/V, diarrhea in some, 1-5 hours of ingestion, resolve in 6-24 hours
most common cause of serious anaerobic infections
Bacteriodes fragilis
need active immunization after recovery
C. tetani
with tetanus toxoid
BIG-IV
human-derived botulism immune globulin for infants less than 1 year of age
C. botulinum
tcdC
negatively regulates transcription and production of A and B toxins in C. difficile
NAP-1/027 does NOT have tcdC: responsible for hyper virulence
red slant/yellow butt
Shigella
glucose fermented, lactose not
red slant/red butt
no fermentation of lactose or glucose
red slant/black butt, Gas
Salmonella
glucose fermented, lactose not
H2 and H2S formed
yellow slant/yellow butt, Gas
E. coli
glucose and lactose fermented, H2 formed