Enterobacteriaceae Flashcards
1
Q
What are the major pathogens of enterobacteriaceae?
A
- E. coli
- Salmonella
- Shigella
- Yersinia
- Klebsiella
- Proteus
- Enterobacter
- Citrobacter
2
Q
enterobacteriaceae are gram ______ with what shape?
A
gram negative rods
3
Q
Do enterobacteriaceae form spores?
A
No they are non-spore forming
4
Q
Enterobacteriaceae are ______ fermenting?
A
glucose
5
Q
Enterobacteriaceae are ______ (areobes or anaerobes)
A
They are facultative anaerobes
6
Q
What types of bacterial enterobacteriaceae are there?
A
normal flora, opportunistic and obligate pathogens.
7
Q
How is control of enterobacteriaceae controlled in relation to public health
A
- water and food safety
-fecal oral transmission common
trash disposal like rodents and vector control
8
Q
How are most Enterobacteriaceae cultured?
A
Most grown on common lab media, A variety of differential and selective media; Macconkey agar, Eosin-Methylene Blue agar, Salmonella-Shiegella agar
9
Q
Sereotyping of Enterobacteriaceae is on the basis of what?
A
O, H K antigens which are also respectively LPS, flagella and capsule.
10
Q
E.coli is a common ____ inhabitant
A
GI
11
Q
E. coli was originally isolated as ______ and renamed as E. coli
A
Bacillus coli communis by Escherich
12
Q
Normal flora E. coli is associated with what?
A
- intestinal disorders (diarrhea),
- urinary tract infections (UTI- most common cause of cystitis)
- Wound infections
- neonatal meningitis
13
Q
How many strains of E. coli are sequenced?
A
61 strains
14
Q
What are the Diarrhea strains of E. coli
A
ETEC EPEC EHEC EIEC EAggEC
15
Q
Strains of E.coli differ in _____ properties these differences are also known as what?
A
virulence properties the differences are known as virotyping.
16
Q
What does ETEC stand for?
A
EnteroToxigenic E. Coli
17
Q
What does EPEC stand for?
A
EnteroPathogenic E. coli
18
Q
What does EHEC stand for?
A
EnteroHemorragic E. coli
19
Q
What does EIEC stand for?
A
EnteroInvasive E. coli
20
Q
What does EAggEC stand for?
A
EnteroAggregative E. Coli
21
Q
What does UPEC stand for?
A
UroPathogenic E. Coli
22
Q
What does E. coli K1 strains cause?
A
neonatal meningitis
23
Q
What strains of E.coli cause Gastroenteritis?
A
ETEC EPEC EHEC EIEC EAggEC
24
Q
what is the genomics for K-12 E. coli strain
A
the commensal strain (MG1655) 4.64 Mb
25
what is the E.coli strain genomics for K-1
nenoatal meningitis strain (UMN 026) 5.36 Mb
26
What is the UTI strain of E.coli?
(IAI39) 5.13
27
What is the genomics for the E.coli strain HUS, hemolytic uremic syndrome
(O104:H4 str. 2011C-3493) 5.44 Mb
28
What is the genomic E. coli strain of EHEC?
E. coli O157:H7
29
Enterohemorrhagic E. coli (EHEC) has how many cases and death per year in the USA?
73,000 cases and 60 deaths per year in the USA
30
How is Enterohemorrhagic E. coli caused?
By the consumption of ground beef and food contaminated with cattle feces.
31
Enterohemorrhagic E.coli contains a shiga-like toxin on lysogenic phage with can do what?
the shiga toxin can move to the kidneys and cause hemolytic uremic syndrome
32
What is hemolytic uremic syndrome (HUS)?
characterized by hemolytic anemia (anemia caused by destruction of RBC), acute kidney failure (uremia) and low platelet count
33
Enterohemorrhagic E.coli (EHEC) colonization is aided by what?
Bacteroides thetaiotaomicron (normal flora)
34
Bacteroides theraiotamicron does what?
aids in EHEC colonization; cleaves fucose from host lycans (mucin); fucose triggers virulence in EHEC>
35
In Enterohemorrhagic E. coli (EHEC) colonization what happens at the tissue surface?
Epinephrine and norepinephrine from tissue activate type III secretion, toxin introduced to intestinal epithelial cells- bloody diarrhea (dysentery).
36
Cattle can be a natural reservoir of ______
Enterohemorrhagic E.coli (EHEC)
37
What are the symptoms of Enterohemorrhagic E. coli (EHEC)?
Abdominal cramps
bloody diarrhea
little or no fever
38
What is the main toxin of Enterohemorrhagic E.coli (EHEC)?
Shiga toxin (A-B5 toxin) which is similar to the main toxin from shigella dysteriae (shiga toxin). The shiga toxin (A-B toxin) binds to globotriaosylceramide-3 (Gb3) (found in colon. G3b is also found in renal glomeruli.
39
Many virulence genes encoded on pathogenicity island 1 in Enterhemorrhagic E. coli is also called what?
Locus of Enterocyte Effacement (LEE)
40
Antibiotic treatment of Enterohemorrhagic E. coli can do what?
cause risk of hemolytic uremic syndrome
41
HUS stands for what and is it life threatening?
Hemolytic uremic syndrome (HUS), potentially life-threatening complications.
42
What type of secretion is used for Enterhemorrhagic E. coli virulences?
Type 3 secretion.
43
Stx (shiga toxin) acts against what? which does what?
acts against host 28S rRNA which inhibits protein synthesis.
44
what is the diagnostic of Enterhemorrhagic E.coli?
Detection of toxin in stool/culture
45
what is the infectious dose of Enterhemorrhagic E. coli?
estimated as 10^-100 CFU
46
IS Enterhemorrhagic E. coli acid resistant?
yes
47
Enterohemorrhagic E. coli (EHEC) does what to lesions?
attaches and effaces.
48
Enterohemorrhagic E.coli has genes for acid resistance with are ____ regulated ______
quorum regualted (sdiA) luxR homolog- E.coli lack lux so need Acyl-homoserine lactones (AHLS) from other bacteria.
49
Ethanolamine is also a signal molecule receptor for ____ which responds to _____ stimulating ____?
ethanolamine (qsec) also responds to host epineprine which stimulates stx and lee gene.
50
Entertoxigenic E. coli (ETEC) causes what?
Traveller's diarrhea
51
Does Entertoxigenic E. coli (ETEC) cause damage to intestinal cells like EHEC does?
No apparaant damage
52
Toxins of Enterotoxigenic E. coli causes what?
- diarrhea similar to cholera but less severe
- Vomiting
- cramps
- fever
53
Enterotoxigenic E. colie (ETEC) is a major cause of child death where?
third world countries.
54
Enterotoxigenic E.coli (ETEC) causes an increase in levels of what?
cAMP or cGMP
55
Enterotoxigenic E. coli (ETEC) has heat stable and labile toxins which does what?
stimulated hyper secretion of fluids and electrolytes.
56
Enteroaggregative E. coli (EAEC) has similar symptoms as _____ except _____
similar symptoms as ETEC except has more persistne diarrhea, Mucoid stool.
57
Enteroaggregative E. coli (EAEC) infections are usually what?
self-limiting and responsive to oral rehydration therapy.
58
How is Enteroaggregative E. colie (EAEC) diagnoses?
HEp-2 cell-adherence assay
59
What are the virulence factors for Enteroaggregative E.coli (EAEC)?
-Aggregative adherence fimbriae (AFF I)
-aggR
-fimbriae (pili)
-enterotoxins
dispersin
protease
-siderophores
-several other factors
60
The virulence factoe Aggregative adherence fimbriae (AFFI) for Enteroaggregative E.coli (EAEC) is what?
cause E. coli to clump together on the surface of intestinal cells.
61
The virulence factor aggr in EAEC is what?
master regulator of pathogenicity island
62
The virulence factor dispersin in EAEC is what?
spread across the EAEC mucosa
63
The virulence factor protease in EAEC is what?
involved in mucin degradation
64
Enteropathogenic E. coli (EPEC) causes what symptoms?
Pediatric diarrhea (watery)
65
How is Enteropathogenic E.coli (EPEC) transmitted?
person to person
66
How is Enterpathogenic E. coli (EPEC) 's adherence?
its patchy
67
What in Enteropathogenic E.coli (EPEC) causes attachment and effacing?
Actin rearrangement
68
What are the virulence factors of Enteropathogenic E. coli (EPEC)?
- actin rearrangement
- Pathogenicity island (locus of enterocyte effacement (lee))
- bundle forming pili
- cytolethal distending toxin and cytotoxic necrotizing factors.
69
Enteroinvasive E. coli (EIEC) has what symptoms which are similar to what?
watery diarrhea which may lead to Dysentry (scant blood); similar symbtoms to Shigella infection
70
How is Enteroinvasive E. coli transmitted?
Cell to Cell spread by actin tail
71
How is the virulence genes in Enteroinvasive E. coli (EIEC) and shigella carried?
by plasmid
72
Uropathogenic E. coli (UPEC) causes a majority ______% of what?
More than 80% of uncomplicated cystitis
73
What is cystitis?
lower urinary tract infection refering to the inflammation of the bladder specifically the wall of the bladder.
74
Uropathogenic E.coli (EPEC) causes what?
- Urethritis (urethra)
- but more commonly cystitis (bladder)
- also Pyelonephritis (kidney) which is the most serious
75
What is urethritis?
inflammation of the urethra
76
What is Pyelonephritis?
Inflammation of the kidneys due to bacteria infection
77
Uropathogenic E. coli (UPEC) is mostly in what group of people?
young girls 20-40
78
Cranberry juice is effective for what?
Preventing UTI's.
79
Antibiotics are given in the case of Uropathogenic E.coli (EPEC) when?
After in vitro susceptibility test.
80
Uropathogenic E.coli (UPEC) is generally what?
an ascending UTI
81
Uropathogenic E.coli (UPEC) need what for colonization of the urinary tract?
Motility and adhesion; witching mechanism is not fully understood however
82
THe virulence factors associated with uropathogenic E.coli (UPEC) include what?
- adherence
- motility
- metal acquisition (Fe, Zn)
- toxin production (hemolysin)
- immune evasion
83
Pili (fimbriae) can influence what in Uropathogenic E.coli (UPEC)?
influence tissue tropism
84
What different types of pili (fimbriae) do uropathogenic E. coli (UPEC) have?
Type 1
p fimbriae
and S fimbrae
85
Type 1 pili fimbrae in UPEC is what?
mannose sensitive and commonly found in most strains
86
the p fimbrae in UPEC is what?
associated with pap gene; is the pyelonephritis associated pili; binds sugar same as human blood group. P- can undergo antigenic variation.
87
the S. fimbrae in UPEC is what?
mannose resistant.
88
Proteus is found where?
GI tract
89
Proteus is a common cause of what?
complicated cystitis and other urinary tract infections (UTIs)
90
What is the major virulence factor of Proteus?
Urease
91
The pili of proteus can what?
undergo antigenic variation
92
How can the cells of proteus change?
from normal morphology to very elongated cells with many flagella.
93
What is involved in the grup behavior of proteus?
signaling
94
What is a common feature of growth of proteus in agar?
swarming
95
A proteus swarm colony from a spot less than 10 raised to the 4 bacteria can cover ___ diameter in apetri dish in about ____ at 32 degrees Celsius
9 cm diameter petri dish in about 12-16 hours at 32 degrees celsius.
96
what is the equation for urease?
NH2CONH2 --->2NH3 + CO2
97
What is the equation for Struvites?
NH2MgPO4
98
Proteus can block what? how?
urinary catheters via biofilms
99
Normal urine pH is what? Struvite needs a pH of what?
Normal pH is slightly acid at ~ a pH of 5.8 While Struvite needs a pH more than 7 often even a pH of 8 or 9.
100
Proteus biofilm growth can create what? enhancing what?
create microenvironments and enhance mineral formation
101
What is a typical difference between Uropathogenic E.coli (EPEC) UTI and a Proteus (p. miriabilis) UTI?
UPEC typically causes an uncomplicated UTI and proteus's bacteria like P . mirabillis typically causes complicated UTIS.
102
Estimated mortality of infected neonates with E.coli meningitis?
40%
