Enterobacteriaceae Flashcards
(98 cards)
1
Q
E.coli : LF/NLF, VP, CIT
A
- LF
- VP NEG
- CIT NEG
2
Q
MACpp NLF
- PDA POS
- H2S POS
A
Proteus
3
Q
MACpp: LF or pale LF or NLF
- VP NEG
- Citrate POS
A
Citrobacter species
4
Q
this toxin is associated with bloody diarrhea
A
SHIGA
5
Q
Usually NOT part of healthy human’s flora; found in water, soil, food
A
Serratia
6
Q
What is prodigiosin
A
Red/pink/orange non-diffusible pigment found in Serratia
7
Q
What is biochemically unique about Serratia (aside from pigment)
A
Produces 3 hydrolytic enzymes
- lipase
- gelatinase
- DNase
8
Q
Serology (O/H/K) is used to confirm what?
A
- Biochemical ID of Salmonella, Shigella (polyvalent O for Salmonella)
- Pathogenic serotypes (monovalent for E. coli O:157)
9
Q
How is Group D Shigella (S. sonnei) differentiated from the other 3 groups?
A
Delayed LF on MAC
10
Q
Proteus, Providencia and Morganella are intrinsically resistant to tetracycline, _______ and colistin
A
NITROFURANTOIN
11
Q
Category A abx
A
- Ampicillin
- 1st gen cefazolin
- Gentamicin
- Tobramycin
12
Q
an acronym for those Enterobacteriaceae that are intrinsically resistant to certain B-lactam drugs (but not the 3rd generation cephalosporins)
A
SPICE
13
Q
MACpp: domed LF
- VP POS
- Citrate POS
A
Klebsiella or Enterobacter
14
Q
K1 antigen is the main virulence factor in ______
A
MNEC
15
Q
abbr. - in this test, FeCl3 is added and a green complex forms in a positive test
A
PDA
16
Q
if this is added to a truly negative nitrate test which is colourless after Nit A and B, a red colour will appear
A
ZINC
17
Q
2 organisms that can cause complicated UTI in the elderly?
A
Proteus, Enterobacter
18
Q
How is Group D Shigella (S. sonnei) differentiated from the other 3?
A
Delayed LF on MAC
19
Q
Where are each of these antigens found on the cell: O, H, K
A
O - outer membrane
H - flagella
K - capsule
20
Q
“currant jelly-like” sputum can result when colonization of this species of Klebsiella progresses to destructive disease in debilitated patients
A
PNEUMONIAE
21
Q
There is no documented intrinsic resistance to the _________ in Proteus mirabilis
A
Beta-lactams
22
Q
All Enterobacteriaceae except Plesiomonas are negative for this test
A
OXIDASE
23
Q
Purpose of selenite enrichment broth?
A
Enhance growth of Salmonella and Shigella while inhibiting normal flora
24
Q
2 words - when Salmonella Typhi sequesters here patients can “shed” the organism and can infect others while they themselves are asymptomatic
A
BILIARY TREE
25
Proteus is associated with alkaline encrusted cystitis, scarring and kidney stones because of hyper-production of this enzyme.
UREASE
26
What/which org(s) have intrinsic resistance against all of: tetra, nitro, colistin?
Proteus, Providencia, Morganella
27
Cronobacter sakazakii and Pantoea agglomerans were at one time included in this genus
ENTEROBACTER
28
Klebsiella pneumoniae is intrinsically resistant to this antibiotic as well as ticarcillin
AMPICILLIN
29
abbr. - organisms that lack permease but produce B-galactosidase will be NLF on MAC at 16-18 hrs., but POS in this test
ONPG
30
Intrinsic R in E. coli?
None
31
Most common E. coli serotype causing hemolytic uremic syndrome (hamburger disease)
STEC (EHEC)
Shiga-toxin producing E. coli (Enterohemorrhagic E. coli)
32
MACpp: LF or NLF
- VP NEG
- Citrate NEG
- Indole POS
E. coli
33
3 key biochemical features shared by this family
- ferment glucose
- oxidase NEG
- reduce nitrates to nitrites
34
this enrichment broth is used to inhibit normal enteric flora while promoting the growth of enteric pathogens within a short incubation period
SELENITE
35
this sugar replaces lactose in a "SMAC" plate; potential pathogens screen as colourless colonies from this stool media plate
SORBITOL
36
Unique among Enterbacteriaceae for oxidatively deaminating phylalanine (an alpha-amino acid) to pyruvic acid (i.e. PD positive; most Enter are PD neg)
Proteus
37
E. coli, Citrobacter koseri, Klebsiella oxytoca and Proteus vulgaris are positive in this test. Citrobacter freundii, Klebsiella pneumoniae and Proteus mirabilis are negative
INDOL
38
Salmonella Typhi has the __ antigen that is specific to it called the __ antigen
K antigen called Vi antigen
39
Serological testing should be done from ______ media
non-selective (BAP, MH)
40
What are the 3 PDA+ organisms?
Proteus, Providencia, Morganella
41
Organism that is the exception to all Enterobacteriaceae being oxidase NEG?
Pleiomonas shigelloides
42
Morphology of MOST Enterobacteriaceae on BAP?
NH lrg gr
43
Specimens that would be received for possible Yersinia?
Blood, sputum, lymph node aspirate
44
___________ are biochemially and antigenically related to Salmonella
Citrobacter
45
this enzyme causes the release of ammonia and CO2 which turns the phenol red indicator a hot pink colour
UREASE
46
Yersinia enterocolitica will appear as a pink "bull's eye" colony an a CIN plate because it ferments this sugar
MANNITOL
47
MACpp NLF
- PDA POS
- H2S NEG
Providencia, Morganella
48
LF, H2S+
C. freundii
Very unique for it
49
Citrobacter: LF/NLF, VP, CIT
- LF
- VP NEG
- CIT POS
50
What to look for on YSA plate (CIN = Yersinia selective agar)?
Bull's eye = mannitol fermented (MF)
51
What are the SPiCE organisms?
Serratia, Proteus, (indole+), Citrobacter, Enterobacter
52
this is the least serious and most common form of the plague caused by Yersinia pestis
BUBONIC
53
What is unique about Yersinia enterocolitica
Slow growing NLF that is motile at room temp, non-motile at 35C
54
abbr. - in this test, lactose and sucrose are present at 10x the concentration of glucose
TSI
55
What morphology to look for on SMAC?
NSF (non-sorbitol fermenter) => indicates E. coli O157
56
2 main differences between Enterbacter and Klebsiella?
Enterobacter are
- motile
- ornithine POS
57
Haloing gnb direct smear => potential org?
Klebsiella
58
BCIT classic E. coli morphology + biochemical
BAP: BH
MAC: LF dry/magenta
Spot indole (+)
Oxidase (-)
59
Causes mild gastroenteritis and is reportable from stools
Edwardsiella
60
2 non-zoonotic pathogens
- Shigella
| - Salmonella Typhi
61
this sugar is fermented by most E. coli, Klebsiella and Enterobacter, variably by Citrobacter, but rarely or not at all by other Enterobacteriaceae studied at BCIT
LACTOSE
62
gnb are typically susceptible to this drug - Serratia, Proteus, Providencia and Morganella are exceptions
COLISTIN
63
enteric fever due to Salmonella Tyohii is termed ____ because it intially presents as blood culture POS but stool culture NEG then switches to stool culture POS but blood culture NEG
BIMODAL
64
Klebsiella: LF/NLF, VP, Orn
- LF
- VP POS
- Orn NEG
65
These 4 are commonly recovered in traumatic wound infections
- E. coli
- Proteus
and/or
- Klebsiella
- Enterobacter
66
while E. coli has no known _____ resistance, acquired resistance is well documented, notably as ESBL producers
INTRINSIC
67
abbr. for the most serious form of illness associated with the EHEC, of which O157:H7 is the most common in this part of the world
HUS
68
abbr. - this term represents indole, motility, VP and citrate
IMVIC
69
this Citrobacter is H2S positive, indol negative
FREUNDII
70
MAC: NLF
- PD NEG
- DNase POS
Serratia
71
3 forms of plague caused by Yersinia pestis?
- bubonic
- septicemic
- pneumonic
72
abbr. - this signifies another group of E. coli that can cause bloody diarrhea due to cellular invasion
EIEC
73
Enterobacter: LF/NLF, VP, Orn
- LF
- VP POS
- Orn POS
74
antibiotics are generally not given to treat Salmonella gastroenteritis because it may promote ____ status in patients
CARRIER
75
NLF on MAC = separate by __ rxn
PD
76
O somatic = heat-______
H flagellar = heat-______
K capsular = heat-______
stable, labile, labile
77
the location of the heat-labile K antigen
CAPSULE
78
2 members of this family that are NEVER motile and why?
Klebsiella, Shigella
Lack flagella
79
this Shigella species causes the most severe disease
DYSENTERIAE
80
abbr. - Other than Proteus, Providencia and Morganella, other Enterobacteriaceae studied at BCIT would be negative in this tube test
PDA
81
Most common gnb causing neonatal meningitis?
MNEC
82
abbr. - a syndrome in which the endotoxin of gnb associated with Lipid A can lead to such intense clotting that factors are depleted resulting in septic shock with hemorrhage and possibly death
DIC (disseminated intravascular coagulation)
83
the heat-stable O antigen
SOMATIC
84
Easiest methods of differentiating Citrobacter freundii and Citrobacter koseri?
Indole and H2S rxns
85
VP+, CIT+, ORN+
Enterobacter
86
LF on MAC = separate by __ rxn
VP
87
4 species of Shigella?
A - S. dysenteriae
B - S. flexneri
C - S. boydii
D - S. sonnei
88
4 main LFs
- E. coli
- Klebsiella
- Enterobacter
- +/- Citrobacter
89
Delayed LF: _____ permease, _______ B-galactosidase
sluggish permease
| HAS B-galactosidase
90
UPEC main virulence factor
Adhesion type 1
91
hyphenated - this scheme is used to serotype Salmonella using O and H1 and H2 antigens
KAUFFMANN-WHITE
92
Citrobacter most commonly causes which disease?
UTI (males >=65 years)
93
this test helps to differentiate LFs that are VP negative
CITRATE
94
Best biochemical test for distinguishing late LF from NLF
ONPG
Helps to distinguish some slow LF E.coli from Shigella
E.coli ONPG+
Shigella ONPG-
95
VP test detects which end product of glucose fermentation?
Acetoin
Gets converted to diacetyl (red/pink complex)
96
pH at which methyl red becomes positive
4.5
97
Urease production test - ammonia reacts to form what product?
Ammonium carbonate
Causes alkalinization which turns phenol red pink at pH 8.0
98
Why is a wet mount motility performed when MALDI identifies E. coli on the enterics bench?
Shigella is similar to E. coli and MALDI can misclassify it
Shigella must be ruled out as it is non-motile while E. coli is motile
