Enterobacterales (Exam 3) Flashcards
The order Enterobacteriacae is made up of (gram-positive/gram-negative) (rods/cocci/spirochetes).
gram-negative rods
Enterobacteriacae are oxidase (negative/positive).
negative
What is the classification of Enterobacteriacae in terms of what oxygen conditions they grow best?
facultative anaerobe
All species within Enterobacteriacae ferment _______ while only some ferment _______.
glucose
lactose
Where is the normal location for Enterobacterales?
GI tract
Enterobacterales typically have (systemic/local) effects.
systemic
What is the route of transmission for Enterobacteriaceae?
fecal-oral contamination
What two ways do Enterobacteriaceae have antibiotic resistance?
- ESBL (extended-spectrum beta-lactamases)
- R-factor plasmids
Of the family Enterobacteriaceae, what four genera are commonly isolated from diseases in vet med?
- Escherichia
- Klebsiella
- Salmonella
- Proteus
What diagnostic test is used for Enterobacteriacae?
triple sugar iron agar (TSI)
_______ agar is selective against gram positive bacteria, and therefore used to help identify Enterobacteriacae.
macconkey
Which agar is selective for Salmonella? Which two allow enrichment for Salmonella (growth advantage)?
brilliant green
selenite broth
tetrathionate broth
IMViC tests separate _______ from other fecal source bacteria in water analysis based on metabolic products.
Escherichia coli
What 4 tests does a IMViC include?
- indole
- methyl red
- voges-proskauer
- citrate
List the 4 varying surface antigens of Enterobacteriaceae family.
O, H, K, F
The variations of O, H, K, and F surface antigens on Enterobacteriaceae determine different ________.
serotypes
Match each surface antigen to its description:
- flagella
- capsule
- fimbria/pili
- region 1 of LPS
- H
- K
- F
- O
(T/F) Enterobacteriaceae usually do not cause disease.
True
What kind of diseases are most commonly caused by Enterobacteriaceae?
GI disease
Clinical signs are very similar between genus and species of Enterobacteriaceae unless _______ are present.
exotoxins
What two methods are used to help diagnose Enterobacteriaceae?
- TSI agar
- oxidase test
(T/F) Bacteria of the family Enterobacteriaceae have highly reactive LPS/endotoxin which causes similar disease manifestations.
True
(T/F) There is high variation in surface structures leading to “variants” of Enterobacteriaceae.
True
Which species of Enterobacteriaceae is pathogenic and a significant animal and human health concern due to widespread outbreaks?
Escherichia coli
What 3 species of Enterobacteriaceae are present with fecal contamination of water?
Escherichia
Enterobacter
Klebsiella
All _______ of E. coli worsen infection.
exotoxin / enterotoxin
What are the 2 types of exotoxins of E. coli?
- enterotoxins
- shiga toxins
_______ are secreted by live bacteria into the cell directly or into the circulation.
exotoxins
What do endotoxins, secreted after bacteria die, induce?
systemic inflammatory effect
Which exotoxin of E. coli is cytotoxic, and therefore, has concern for endothelial damage?
shiga toxin
Regarding enterotoxins of E. coli, there are two types: _____ toxin is small peptide which is non-immunogenic while _______ toxin is an AB type protein than is immunogenic.
stable
labile
Grossly, what do shiga toxins cause?
bloody diarrhea
Enterotoxins cause hypersecretion of ________ and _______ in the small intestine.
water
electrolytes
Heat-labile enterotoxins activate ________ which generates ______, causing hypersecretion in the small intestine.
adenylyl cyclase
cAMP
Heat-stabile enterotoxins have two units, STa which activates _______ and hypersecretion, and STb which causes ion imbalance, ________ production, and disruption of barrier function leading to hypersecretion.
guanylyl cyclase
prostaglandins
What do the following tests look for?
Ligated gut loop test
Infant mouse test
Y-1 mouse adrenal cell test
PCR
production of enterotoxin
(T/F) Shiga toxin is an AB toxin and the A domain is the active form.
True
What does STEC stand for?
shiga toxin producing E. coli
