Enterobacteriaceae Flashcards
1
Q
characteristics
A
- facultative anearobe or aerobe
- motile with peritrichous flagella except for KELBSIELLA & SHIGELLA
- has pilli/ fimbriae for attachment
- members of this family may posses ANTIGENIC DETERMINANCE
2
Q
Motile at what temp?
A
- at room temp (20-22) but non motile at 37 is genus yersinia, except yersinia pestis
3
Q
grows well on what agar
A
- MacConkey agar ( selective differential)
- BAP (dlarge dull gray colonies with variable hemolysis)
4
Q
ferments what?
A
glucose –> gas production (except shigella)
5
Q
catalase positive except
A
shigella dysenteriae
6
Q
cytochrome oxidase negative except
A
plesiomonas
7
Q
2 groups of enterobacteriacae
A
intestinal and opportunistic
8
Q
intestinal pathogens
A
- never normal flora
- salmonella, shigella, yersinia entercolitica
9
Q
opportunistic pathogens
A
- GIT flora that can cause infections outside the GIT
10
Q
Antigenic determinance
A
- used on serologic test
- can be used to identify salmonella, shigella and, kelbsiella and e.coli
11
Q
O or somatic antigen
A
- Outermost part of the cell wall
- heat stable
- 164 types in E. coli
- 4 serotypes in Shigella (A,B,C,D)
12
Q
K or envelope antigen or capsular antigen
A
- consist of capsular polysaccharide
- heat labile
- said to have K-antigen: E. coli, klebsiella, salmonella
13
Q
H flagellar antigen
A
- found only in motile members of the family ( Shigella and Klebsiella do not have)
- protein in nature
- heat labile
14
Q
Serotype 0111
A
causes diarrhea in infants
15
Q
Serotype 0157
A
associated with vero toxin production
16
Q
S. typhi
A
said to have Vi antigen, this antigen is categorized as K antigen
17
Q
sample used to detect this family
A
stool
18
Q
plated media used of intended for this family
A
MacConkey, EMB (Eosin methylene blue agar) and SSA (Salmonella Shigella (SS) Agar)
19
Q
what to do with growth after incubation?
*direct detection in stool is insignificant because if the large number of normal flora
A
- use in smear preparation (gram staining)
- members of this family have similar microscopic appearance —> insignificant for initial detection
20
Q
Screening test for this family
A
Oxidase test
any organism that has negative (-) result for this test is suspected to be a member of this family
21
Q
used to identify the genera or species after oxidase test
A
series of biochem test
- carbohydrate fermentation test
- ONPG test
- gelatin hydrolysis test
- IMVIC test
- urease test
- Deaminase test
22
Q
2 most common culture media
A
MacConkey and EMB
23
Q
what kind of media is MacConkey and EMB
A
selective - differential
no gram (+) can grow on this media because they have inhibitory agents
both ferments lactose
indicators:
EMB - eosin Y and methylene blue
MacConkey - neutral red
Fermenters - turn pink/ purple
Non-fermenters - colorless
24
Q
inhibitory agent for EMB
A
eosin methylene blue
25
inhibitory agent for MacConkey
bile slats and crystal violet
26
XLD agar
selective - differential media
indicator - phenol red
ferments lactose, sucrose and xylose
fermenters - yellow
non-fermenters- red/ colorless
27
Hektoen Enteric Agar (HEA)
selective - differential media
indicator- bromthymol blue
ferments salicin, lactose and sucrose
fermenters- yellow with or without black
non-fermenters- green/ colorless with or without black
28
SSA (salmonella shigella agar)
in some books this is selective media, selective-differential in others
ferments lactose
indicator-neutral red
fermenters- red
non-fermenters
- colorless with black center SALMONELLA
- colorless w/o black center SHIGELLA
29
BSA (bismuth sulfite agar)
selective media for salmonella
ferments glucose
indicator- bismuth blue
black colonies
30
Enrichment media
GN broth
Selenite broth - for Salmonella and Shigella
Tertathionate broth - for Salmonella
31
CIN (cefsulodin irgasan novobiocin)
selective for Yersinia
indicator- neutral red
contains manitol
32
EMB
Klebsiella pnuemoniae - pink to purple mucoid colonies (bc it is encapsulated)
E.coli- pink to purple colonies with greensih metalic sheen
Enterobacter - pink to purple colonies with black centers giving it a FISH EYE appearance
THESE ARE RAPID LACTOSE FERMENTERS
33
Carbohydrate fermentation test
done to detect acid production
Media: TSI (triple sugar iron)
that is dispensed as butt & slant, traditional media used for detection of carbohydrate fermentation
34
Components of TSI
10 parts lactose, 10 parts sucrose, 1 part lactose
pH indicator - phenol red
H2S indicator - sodium thiosulfate and ammonium sulfate
35
possible results of carbohydrate fermentation test
acid pH - YELLOW
alkaline pH - REMAIN RED
H2S production - BLACKENING
gas production - SPILLTING, CRACKING PULLING AWAY OF MEDIA
36
how to read result of carbohydrate fermentation test
read as slant/butt
Acid/ yellow = A
Alkaline/ red = K
37
replacement of TSI of not available
Kligler's Iron Agar
38
Kligler's Iron Agar
has the same components of TSI except sucrose
39
K/K interpretation and classification
no sugar was fermented
NON-FERMENTER --> not a member of family enetrbacteriacae
Pseudomonas aeruginosa - no.1 non-fermenter
40
K/A interpretation and classification
only 1 sugar was fermented (glucose)
| NON-LACTOSE FERMENTER
41
A/A interpretation and classification
2-3 sugars were fermented
Glucose (+); lactose or sucrose (+)
LACTOSE FERMENTER
42
Lactose fermenters
EEK (ew embaho ko)
Enterobacter
Escherichia
Klebsiella
43
Late/ slow lactose fermenters
ONPG test is used
C3SY (C3SY yaw q na)
```
Citrobacter
Serratia
S. arizonae
S. sonnei
Y. enetercolitica
```
44
non-lactose fermenters
PMPE (pepe mong panget echos)
Poteus
Morganella
Providensia
Endwadrsiela
all salmonella except S. arizona
all shigella except S. sonnei
all yersenia except Y. enterocolitica
45
ONPG test is used to detect what
1. late lactose fermenters
2. differentiate citrobacter (+) from salmonella (-) except for arizona
ONPG broth or disk
(+) YELLOW
46
ONPG positive
```
Eskerichia coli
Kelsiella spp.
Y. enterocoliticus
enterobacter
citrobacter spp.
S. sonnei
H. aleveli
A. arizonae
```
47
ONPG negative
```
Proteus spp.
Salmonella spp.
Shigella spp.
Providensia
Y. pestis
Morganella
Y. pseudotuberculosis
```
48
Gelatine hydrolysis test
organism is inoculated in nutrient gelatin media incubated for 14 days at 35-37C ---> daily remove from incubator and place in ref for 30 mins or until the media has gelled ( since it is a semi solid media if this is not done it will liquefy)
(+) GEL LIQUEFACTION
(-) COMPLETE SOLIDIFICATION AT 4C
49
used in the detection of serratia
Gelatine hydrolysis test and DNAse
50
IMViC test
Indole-Methylene- Vouges Proskauer-Citrate
used to differentiate rapid lactose fermenters (EEW)
uses 4 tubes
51
INDOLE test
used to detect the ability of organism to produce indole from tryptophan ( to detect enzyme tryptophanase)
52
METHYLENE RED test
used to detect acid production when glucose is metabolized
53
VOGES PROSKAUER test
used to detct the ability of the organism to produce acethylmethyl carbinol ( acetoin)
54
CITRATE UTILIZATION test
to detect ability of organism to use citrate at the only carbon source
55
where to inoculate when doing indole test
Sim media - a semi-solid media dispensed as butt
Tryptophan broth
incubate --> inoculation --> add reagent
56
Reagent for indole test
KOVAC'S OR EHRLICH'S REAGENT
EHRLICH'S REAGENT is more sensitive in detecting small amounts of indole
57
indole test results
(+) red ring at the junction
| (-) no color development
58
where to inoculate when doing MR test and VP test
MRVP broth or clark lubbs broth
59
reagent for MR test
methyl red
60
MR test result
(+) distinct red color pH less than 4.5
| (-) no color change
61
VP test reagent
Barrits method - 5% alpha naphtol & 40% KOH
Coblentz - creatine & 40% KOH
62
VP test results
(+) pink to red color
| (-) no color
63
Citrate utilization inoculation medium
Simmon citrate agar - tube media dispensed as slant; green when uninoculated
64
Citrate utilization test reagent
no reagent added - because the media has incorporated incubator BROMTHYMOL BLUE
65
Citrate utilization test result
(+) BLUE - Prussian
| (-) GREEN
66
how to read IMViC test result
read results after 24hrs except MR test
MR test- read after 48 hrs, because after 24 hours it is false positive because all members of family enterobacteriacaea are MR positive after 24 hrs
67
chemical name for KOVAC's
paradymethyl aminobenzaldehyde
68
MRPV reactions are always?
OPPOSITE
| if MR is positive VP is negative and VV
69
K/K H2S (-)
PB ( panget si burk)
Pseudomonas & Burkholderia
70
K/A H2S (-)
PMS
Providencia
Morganella
Shigella
71
K/A H2S & Gas (+)
SPACE
```
Salmonella
Proteus
Arizona
C. freudi
E. tarda
```
72
A/A H2S (-) & Gas (+)
EEK
Escherichia
Enterobacter
Klebsiella
73
Urease test
used to detect PPM (proteus - providencia - morganella)
based on the ability of the organism to convert urea from ammonia through the action of enzyme urease
Christensen urea agar/ urea broth
74
test for suspected PPM
manual identification use Urease and Deaminase (priority test)
but can also use ONPG and IMViC
75
PPM (proteus - providencia - morganella)
rapid urease producers - within 4 hrs
76
slow urease producers
after 4 hrs
```
KEY-SC
Klebsiella
Enterobacter
Yersinia
Serratia
Citrobacter
```
77
indicator for urea test
phenol red
78
results in urea test
(+) PINK
| (-) NO CHANGE OR YELLOW
79
Rapid urease producers aside from PPM
HUNT-C
```
H. pylori
Ureaplasma (urogenital pathogen)
Nocardia
C. neofromans
T. metangrophytes
```
80
Deaminase test
also used to identify PPM
81
what does deaminase test use for inoculation
LapTriP
lysine, tryptophan and phenylalanine
overnight culture
82
Deaminase test result
(+) with phenylalanine agar GREEN
(+) with tryptophan agar BROWN
(+) LIA (lysine iron agar): PPM
83
deaminase test detector reagent
10% ferric chloride
84
test that will separate Salmonella and Shigella
2MHD
1. motility test
2. malonate utilization test
3. to detect H2S production
4. Decarboxylase test
85
Motility test
used to detect motile species
but in family eneterobacteriacae it is used to detect non-motile Klebsiella and Shigella
SALMONELLA - non-invasive & motile
SHIGELLA - invasive & non-motile (can cause bloody diarrhea)
86
Media for motility test
sim media - semi solid media displayed as butt
innoculation --> incubate
inoculate by stabbing
87
motility test results
(+)/motile - outside the line on inoculation
(-)/ non- motile - at the line
SIM MEDIA + TTC - is used for easy reading of results
(triphenyl tetrazolium chloride- colorless dye that turns red with organism growth) - optional only
88
Malonate utilization test
detect the ability of the organism to use sodium as the only carbon source
89
Indicator for malonate utilization test
bromthymol blue
90
results for malonate utilization test
(+) blue --> salmonella
| (-) green --> shigella
91
Test to detect H2S production
uses any media provided that it has indicator for H2S production
92
media with H2S indicator
TISH
TSI
LIA
SIM (most sensitive to H2S)
HEA
93
H2S indicator for HEA, SSA and LIA
ferric ammonium citrate
94
(+) H2S production
blackening
```
SALMONELLA
Edwarsiella tarda
Citrobacter freudii
Proteus vulgaris
Proteus mirabilis
```
95
Decarboxylase test
detect the ability of the organism to remove carboxyl group from specific amino acid through the release of enzyme decarboxylase
the ability of the organism to produce decarboxylase that is needed in order to remove carboxyl group from the amino acid
96
3 amino acids that can be used for decarboxylase test
LOA
Lysine
Ornithine
Arginine
97
What carboxyl is removed from Lysine?
Cadaverine
LC (laway conscious)
98
What carboxyl is removed from Ornithine?
Putrescine
OP (out of place)
99
What carboxyl is removed from Arginine?
Citrulline
AC (aircone)
100
2 options to use for Decarboxylase test
LIA or Moeller's broth
101
result for decarboxylase test
(+) purple
(-) yellow
first few hours turn yello (when glucose is fermented) then after and when amino acid is attacked it will turn purple (decarboxylation)
102
indicator for decarboxylase test
bromcresol purple
103
Moeller's broth components
basale media + bromcresol purple + 1 % glucose + amino acid
inoculate --> overlay with mineral oil --> incubate
104
test names for decarboxylase test
Lysine decarboxylase test
Ornithine decarboxylase test
Arginine dihyrdrolase test
105
purpose of mineral oil
will act as oxygen barrier --> will make the environment anaerobic
106
Salmonella resembles what?
Citrobacter
107
Shigella resembles what?
E. coli
108
LIA (lysine iron agar)
not a biochemical test
a tube media used to detect deamination and decarboxylation
dispensed as slant and butt
can also detect production of H2S
3 in 1 test
109
what is used to observe for deamination?
SLANT
110
what is used to observe for decarboxylation?
BUTT
111
result for deamination
(+) burgundy/ red
| (-) purple
112
interpretation for purple/ purple on LIA
K/K
(-) deamination
(+) decarboxylase
SALMONELLA
113
interpretation for purple/ yellow on LIA
K/A
(-) deamination
(-) decarboxylase
SHIGELLA
114
interpretation for red/yellow on LIA
R/A
(+) deamination
(-) decarboxylase
PPM
115
Reported as K/K
EKESEHES (eagle knows every sound every hi every song)
```
Escherichia coli
Kelbsiella spp.
Enterobacter app.
Serratia spp.
Enterbacter spp.
Hafnia spp.
Edwarshiella tarda.
Salmonella spp.
```
116
Reported as K/A
SEY-C
Enterobacter cloacae
Citrobacter spp.
Yersinia spp.
Shigella spp.
117
Reported as R/A
PPM
118
PPM
biochemically similar, rapid urease producers (within 4 hrs) and deaminase (+)
non-lactose fermenters
reported K/A on TSI
119
2 significant species of Genus Proteus
Proteus vulgaris
| Proteus mirabilis
120
Proteus mirabilis
most commonly isolated
| may cause pneumonia and septicemia
121
Proteus vulgaris
causes nosocomial UTI
122
Genus Proteus
used as a source of antigens in Weil Felix Test (a serologic test used to detect rickettsial infections)
Proteus vulgaris -OX2 & OX19
Proteus mirabilis - OXK
123
Genus Proteus colonies
colorless colonies (because they are non-lactose fermenters) with burnt chocolate/ burnt gun powder odor
shows SWARMING on BAP
124
Genus Providencia
no swarming
normal intestinal flora
species: P. rettgeri and P. stuartii
125
Genus Morganella
no swarming
Species: M. morganii
can cause UTIs and RTIs
126
Genus Yersinia
motile at room temp but not motile at 37C - except for yersinia pestis
PEP
Yersinia pestis
Yersinia enterocolitica
Yersinia pseudotuberculosis
127
Yersinia pestis
causative agent PLAGUE - transmitted through flee bites
bioterrorism agent
128
Yersinia pestis colonies
safety pin appearance because of bipolar staining of wayson stain/ methylene blue
liquid media- stalactite/
flocculent growth
on BAP- hammered copper colonies (can be noted only after 48 hrs-shinning)
129
Yersinia enterocolitica
causes enterocolitis - symptoms are mistaken for appendicitis
late lactose fermenter
can tolerate cold enrichment (can grow at 4C for several weeks)
130
causes psuedoappendicular syndrome
Yersinia enterocolitica
131
Yersinia enterocolitica colinies
bull's eye colonies on CIN media (contains neutral red and mannitol)
colorless colonies or pink colonies with red center
132
Yersinia pseudotuberculosis
agent pf mesenteric lymphadenitis
133
Spread via fecal oral route
Salmonella and Shigella
134
Genus Shigella
has 4 serotypes (A,B,C,D)
Causes shigellosis/ bacillary dysentery (bloody diarrhea because they are invasive)
can produce endtoxin
135
Shigella serotype A
Shigella dysenteria / shiga bacillus
lactose fermenter
can produce endotoxic and neurotoxin (why it is most severe)
136
Shigella serotype B
Shigella flexneri / strong's bacillus
lactose fermenter
137
Shigella serotype C
Shigella boydii / new castle manchesters bacillus
lactose fermenter
138
Shigella serotype D
Shigella sonnei /duval's bacillus
late/ slow lactose fermenter
139
Genus Salmonella
can cause an number of infections
140
causes typhoid fever
S. typhi
141
site of long term S. typhi
gall bladder
142
2 primary species of genus salmonella
S. enterica - human pathogen
| S. bongori - animal pathogen
143
Genus Enterobacter
are normal intestinal flora but can cause opportunistic infections
144
most predominant isolate of enterobacter
E. cloacae
145
E. sakasakii --> now Cronobacter sakasakii
causes yellow pigment that intensifies at room temp
can cause necrotizing colitis due to powdered infant milk formula
146
Genus Klebsiella significant species
Klebsiella pneumoniae
147
Klebsiella pneumoniae
friedlander's bacillus
can cause community acquired pneumonia (produces currant jelly like sputum)
*if rust colored sputum = spretococcus pneumoniae
encapsulated = naufeld quellang (+)
148
Klebsiella pneumoniae colonies
mucoid = string test (+)
149
biochemically what resembles K. pneumonia?
K. oxytoca
can be differentiated by indole test
(+) K. oxytoca
(-) Pneumoniae
150
Genus Escherichia
most significant is E. coli
151
Escherichia coli
aka COLON BACILLUS
#1 cause of UTI
normal GIT flora that's why it is found in normal stools (+) always in stool
primary marker of fecal contamination
A/A on TSI
IMViC: ++--
152
2 serotypes of E.coli
Nephrapathogenic E.coli/ Uropathogenic E.coli- causes UTI
Diarrheagenic/ Enterovirulent E.coli - causes diarrhea
153
ETEC
entertoxigenic e. coli
causes profuse/ severe watery diarrhea that is CHOLERA LIKE (not bloody)
154
EIEC
enteroinvasive e.coli
causes bloody diarrhea but not severe that is shigella like
155
EPEC
enteropathogenic e.coli
non-toxigenic & non-invasive but can cause diarrhea in infants
156
EAEC
enteroaggregative e.coli
acute and persistent diarrhea in children and adults
causes mucoid watery diarrhea w/o RBCs or WBCs
157
DAEC
diffusely adherent e.coli
constitutes the 6th group in enterovirulent e.coli
can cause diarrhea in healthy patients -- watery diarrhea w/o RBCs and WBCs
158
EHEC/VTEC/ STEC
MOST SIGNIFICANT!
enterohemorrhagic e.coli/ verotoxic e.coli/ shiga toxin producing e.coli
causes severe bloody diarrhea due to its ability to produce VEROTOXIN
specific example: E.coli 0157:H7
159
E.coli characteristics
all lactose (+) on MacConkey agar --- pink purple colonies (NO EXCEPTION)
160
used to detect E.coli 0157:H7
Sorbitol MacConkey agar
instead of lactose it contains sorbitol, but same
indicator: neutral red
inhibitor: crystal violet and bile salt
all are positive except for 0157:H7
161
MUG test
used to characterize vero tixin producing e.coli
Prepared by impregnating MUG (4-methylumbelliferyl-B-D-glucronide)
to detect B-D-glucronidase priduuces by E.coli and otherr enterobacteriacae
162
results for MUG test
(+) electric blue fluorescence under UV
(-) no fluorescence
if it is a colorimetric assay:yellow
(-) E.coli 0157:H7
163
Red pigment produced by Serratia marcescens
PRODIGIOSIN
164
Genus known to produce a number of enzymes such as DNase, Gelatinase, Lipase
SERRATIA
165
Considered as a late lactose fermenter, with delayed citrate activity
Hafnia alvei (Formerly Enterobacter hafniae)
166
Can cause secretory diarrhea in AIDS patients with inflammatory bowel disease
Plesiomonas shigelloides
167
Can cause wound infections & bacteremia
Edwardsiella tarda
168
Brilliant green agar
for salmonella except for S. typhi
snow flake colonies
169
Brilliant green agar indicator
phenol red
170
Brilliant green agar inhibitory agent
brilliant red
171
EAEC and DAEC
may cause pediatric diarrhea
