Gram Neg Rods Enteric

Front 1

where do these organisms cause disease

Back 1

-GI tract: diarrhea, disentery(bloody, pus in diarrhea), food poisoning, gastritis, peritonitis
-UTI:
-sepsis, meningitis, pneumonia

Front 2

disease typically toxin mediated

Back 2

-endotoxin
-secretory toxins (exotoxin/enterotoxin):
these generally infect small intestine, causes watery diarrhea, nausea, vomiting, little fever or cramps
-invasion of mucosa: invasins
infect large intestine, bloody diarrhea, fever, cramps, leukocytes in stool

Front 3

virulence genes

Back 3

pathogenicity islands-areas on bacterial genomes that contain genetic info that codes for toxins or other pathogenic compounds
-quarum sensing: bacteria communicate and detect when there are lots of the saem bacteria

Front 4

inflammatory & immune components

Back 4

some associated w/ autoimmune disease

Front 5

enteric bacteria diagnosis

Back 5

-history and physical
-specimen staining(gram-, shapes, structures, ie flagella)
-culture:
differential media: changes color depending on the type of bacteria growing
selective media: example: only gram pos can grow on it
-lactose fermentation test: most enterobacteriaceae are lactose + stain purple, salmonella/shigella are lactose neg transluscent
-cyto oxidase: pos or neg determines possession of cyto oxidase system
-biochem and serologic test panels, motility
-nucleic acid detection
-host immune response detection (serum Ab to microbes)

Front 6

enterobacteriaceae family of organisms

Back 6

-facultative anaerobes
-oxidase -
-ferment glucose
-includes E.coli, salmonella, shigella, proteus, yersinia
-some lactose +; other lactose -

Front 7

vibrionaceae

Back 7

-facultative
-curved rods
-oxidase +

Front 8

pseudomonadaceae

Back 8

-aerobes, dont ferment
-oxidase +

Front 9

campylobacteriaceae

Back 9

curved
microaerophilic
oxidase +

Front 10

helicobacter

Back 10

-curved
-microaerophilic
-oxidase +
-urease +

Front 11

E. Coli general features

Back 11

-most abundant facultative normal flora in colon
-diseases: both in and out GI
gastroenteritis-travelers diarrhea
-UTI
-gram - sepsis: endotoin and capsule are important
-meningitis in neonates along w/ strep B and listeria-strains w/K1 capsule
-pneumonia-microaspiration
-intra-abdominal infection: trauma, anatomic disruption, polymicrobic-w/anaerobes

Front 12

E. Coli structure and physiology

Back 12

-gram neg rod
-facultative, glucose fermenter, reduce nitrates to nitrites for energy
-lactose pos, cyt oxidase neg
-serology typing by surface antigens:
O,H,K antigens important, O157 H7

Front 13

macconkey agar

Back 13

-has lactose in it and differentiates lactose + from lactose -
-lactose + turns purple, lactose neg is translusent

Front 14

E. Coli virulence factors

Back 14

-adhesins: pili, O Ag, surface proteins
-capsules K1-antiphagocytic/anti-C'
-endotoxin-LPS
-exotoxins- watery or bloody diarrhea. LT-plasmid coded, stimulates cAMP, ST-stim cGMP
-hemolysins (cytotoxic) and siderophores (Fe scavengers)

Front 15

4 types of E. Coli

Back 15

-enterotoxigenic E. Coli-watery diarrhea
-enteropathogenic E. Coli-watery diarrhea of long duration mostly in infants-developing countries, carries it own receptor, inserts its own receptor into the cell, which allows bacteria to bind infected cell
-enterohemorrhagic E. Coli(O157:H7): bloody diarrhea; hemorrhagic colitis and hemolytic uremic syndrome (HUS)
-enteroinvasive E. Coli: bloody diarrhea

Front 16

differentiating the different types of E. Coli

Back 16

-see table in syllabus:
-site of activity-watery diarrhea is small intestine
-traveler's diarrhea is ETEC
-hemorrhagic EHEC
-EPEC infant and kids
-no fever for ETEC