BACTE ENTEROBACTER Flashcards
(161 cards)
1
Q
All Enterobacteriaceae are:
A
❖ Facultative anaerobe
❖ Non-spore former
❖ Glucose fermenters
❖ Cytochrome oxidase negative
2
Q
✿ All members of enterobacter are motile except
A
❖ Kleibsella and Shigella
❖ Yersinia
3
Q
✿ Motile members have ______________________
A
peritrichous flagella
4
Q
❖ All members grow luxuriantly on BAP as __________________________________ colonies
A
moist, smooth, gray, shiny, entire, convex and opaque
5
Q
Most common route of infection
A
Fecal-oral route
6
Q
✿ Presumptive Identification is best done using selective and
differential media such as:
A
❖ MacConkey (MAC)
❖ Hektoen Enteric Agar (HEA)
❖ Xylose-lysine deoxycholate agar (XLD)
❖ Salmonella-Shigella Agar (SSA)
7
Q
- often part of the usual
intestinal microbiota of both humans and animals
A
Opportunistics Pathogens
8
Q
not present as commensal biota in
the GI tract of humans
A
Primary Pathogens
9
Q
✿ The most significant species in the genus Escherichia
✿ previously considered as a harmless member of the colon
biota
✿ Primary marker of fecal contamination in water
A
Escherichia coli (COLON BACILLUS)
10
Q
✿ Colony Morphology of E. coli in MAC
A
lactose fermenter(pink colony) with surrounding
area of precipitated bile salts
11
Q
✿ Colony Morphology of E. coli in EMB
A
green metallic sheen
12
Q
BIOCHEMICAL CHARACTERISTIC
of E. coli
A
✿ Fermenter of: Glucose, lactose, trehalose and xylose
✿ Indole +
✿ MR+, VP-
✿ Negative for H2S, DNAse, Urease and PAD
✿ Citrate -
13
Q
most common cause of diarrheal disease referred to as Traveller’s diarrhea/Tourist’s diarrhea/Montezuma’s
revenge
A
ENTEROTOXIC Escherichia coli (ETEC)
14
Q
ETEC infective dose of organism for
immunocompetent individual
A
10^6 - 10^10
15
Q
ETEC MOT
A
Ingestion of contaminated food and water
16
Q
Colonization of ETEC in the small intestine mediated by ___________________
A
fimbriae
17
Q
serves as a protective mechanism
against colonization of ETEC
A
stomach acidity
18
Q
ETEC toxin released in the small intestine
A
❖ Heat-labile toxin (LT)
❖ Heat-stable toxin (ST)
19
Q
Manifestation: fever, severe abdominal cramps, malaise and
Bloody diarrhea
A
ENTEROINVASIVE Escherichia coli (EIEC)
20
Q
EIEC MOT
A
fecal oral route
21
Q
EIEC Virulence test
A
Sereny Test
22
Q
Infective dose of EIEC and Shigella
A
EIEC- 10^6
Shigella- 10 Organisms
23
Q
was the first diarrheagenic E.coli described
A
ENTEROPATHOGENIC Escherichia coli (EPEC)
24
Q
causative agent of infantile diarrhea
A
ENTEROPATHOGENIC Escherichia coli (EPEC)
25
EPEC infective dose
10^8 - 10^10 viable cells
26
Manifestations: Low-grade fever, malaise, vomiting with
persistent watery diarrhea, typically in children younger than 2
years old
ENTEROPATHOGENIC Escherichia coli (EPEC)
27
EPEC Pathophysiology
❖ Bundle-forming pilus
❖ Tir (translocated intimin receptor)
❖ EspF (E.coli secreted protein F)
28
Refers to E. coli strains that produce Shiga toxin 1 (Stx1)
and/or Shiga toxin 2 (Stx2)
SHIGA TOXIN-PRODUCING Escherichia coli (STEC)
29
_____ is as referred to as verotoxin because this cytotoxin
produces damage to Vero cells
Stx
30
ENterohemorrhagic E.coli strain
0157:H7 strain
31
EHEC is a subset of STEC that causes ______
Hemolytic Uremic Syndrome
32
❖ Characterized by: Low platelet count, hemolytic
anemia and kidney failure
❖ Stool sample does not contain leukocytes
Hemolytic Uremic Syndrome
33
✿ considered a cause of diarrhea in patients with HIV
✿ White blood cells and red blood cells are often absent from
the stool
ENTEROAGGREGATIVE Escherichia coli (EAEC)
34
EAEC adhere packed in an aggregative ___________________ on the cells and between the cells by means of fimbriae
and can lead to biofilm formation
"stacked-brick” pattern
35
Pathophysiology: Diarrheal Symptoms
❖ Watery diarrhea,vomiting, dehydration, occasional
abdominal pain (mostly in children)
❖ Suggestive: “stacked brick growh pattern” on
monolayer cell culture
❖ Definitive: agDNA probes for virulence genes
ENTEROAGGREGATIVE Escherichia coli (EAEC)
36
✿ widely recognized as the most common cause of UTI
✿ originate in the Large intestine as resident flora
UROPATHOGENIC Escherichia coli Infections
37
UROPATHOGENIC Escherichia coli Infections Virulence Factors
Pili
Cytolysin
Aerobactin
flagella
38
allows UROPATHOGENIC Escherichia coli to adhere to the urinary
epithelial mucosa
Pili
39
UROPATHOGENIC Escherichia coli kill immune effector cells and inhibits
phagocytosis and chemotaxis of certain WBC’S
Cytolysin
40
allows UROPATHOGENIC Escherichia coli to chelate iron
Aerobactin
41
facilitate bacterial dissemination
Flagella
42
✿ Pathophysiology: Lower UTI and acute pyelonephritis
UROPATHOGENIC Escherichia coli Infections
43
one of the most common causes of septicemia and
meningitis among neonates
Escherichia coli
44
most documented virulence factor
associated with neonatal meningitis and septicemia infection
Capsular antigen K1
45
Escherichia coli Infections are acquired in the __________________ during delivery
birth canal
46
species isolated from urine, blood, wounds, feces and
gallbladder
✿ E. fergusonii
47
species associated with diarrheal disease; some strains
carry stx2f gene (Shiga-like toxin) and cdtB gene (toxin found
in Clostridium difficile)
✿ E. albertii
48
formerly called E. coli atypical or enteric
group II; yellow pigmented colonies; isolates from CSF,
wounds and blood
✿ E. hermannii
49
species isolated from humans with infected wounds;
half of the strains produced yellow pigmented colonies
✿ E. vulneris
50
✿ usually found in the G.I tract; free living in soil, water and
plants
✿ associated with various opportunistic and
health-care-associated infections, particularly pneumonia,
wound infections and UTIs
KLEBSIELLA
51
all KLEBSIELLA spp are ______________
encapsulated and nonmotile
52
the most commonly
isolated klebsiella spp. and has distinct feature of possessing a large polysaccharide capsule
✿ K. pneumoniae subsp. Pneumoniae
53
GENERAL CHARACTERISTICS of Klebsiella spp.
✿ Citrate (+) and can grow in KCN broth
✿ H2S (-), MR (-) and VP (+)
✿ Do not produce indole (except for some)
✿ Urease (+) and ornithine decarboxylase (-)
✿ They possess O and K antigens
54
___________________ aka FRIEDLANDER’S BACILLI
KLEBSIELLA PNEUMONIAE
55
✿ most common isolated species
✿ has a polysaccharide capsule (Distinct Feature)
KLEBSIELLA PNEUMONIAE
56
❖ Confers protection against phagocytosis and
antimicrobial absorption
❖ Responsible for the moist, MUCOID colonies
polysaccharide capsule
57
All Klebsiella spp. are lactose fermenters except ______________________________
K. ozaenae and K.
rhinoscleromatis
58
LABORATORY DIAGNOSIS of K. pneumoniae
✿ Gram stain: gram negative bacilli
✿ Culture: large, moist, mucoid colonies on EMB, MAC and
XLD
✿ Quellung reaction (+)
✿ Biochemical Test:
❖ A/A, gas (+), urease (+)
❖ IMVIC: - - ++
59
resemble K. pneumoniae in its disease
spectrum and biochemical properties; isolated from nasal
secretions and cerebral abscess. (IMVIC: + - + + )
K. oxytoca
60
may contribute to the condition called ozaena
which is a chronic atrophic rhinitis characterized by a fetid odor
K. ozaenae
61
causative agent of rhinoscleroma, a
chronic, granulomatous infection of the nasal passages,
pharynx and larynx
✿ K. rhinoscleromatis
62
species has been implicated in human urinary tract
and wound infections
K. planticola
63
species isolated only from the environment
K. terrigena
64
✿ Inhabits soil and water, to a lesser extent the large bowels
of man and animals
✿ Often confused with klebsiella in terms of growth in MAC
ENTEROBACTER spp.
65
ENTEROBACTER Must be differentiated from klebsiella ________________
BIOCHEMICALLY
66
ENTEROBACTER Growth on EMB show _______________
“Fish Eye Colonies”
67
All ENTEROBACTER are motile and with exception of ______________________
E. agglomerans
68
ENTEROBACTER infection are usually ________________
Nosocomial
69
most common clinical
isolates of Enterobacter
E. cloacae and E. hormaechei
70
nonmotile member of Enterobacter
E. asburiae
71
enterobacter associated with osteomyelitis after
traumatic wound
E. cancerogenus
72
ENTEROBACTER BIOCHEMICAL TEST
✿ Simmon;s citrate (+)
✿ MR (-), VP (+)
✿ Ornithine and lysine decarboxylase (+)
73
most common CRONOBACTER human
isolates
C. sakazakii and C. malonaticus
74
❖ Isolated as a pathogen in neonates causing
meningitis and bacteremia
❖ Acquired often from powdered milk
Cronobacter (Enterobacter) sakazakii
75
Cronobacter (Enterobacter) sakazakii Produces a ______________________ colonies
typical yellow pigmented
76
✿ Motile, slow lactose fermenters; but sucrose fermenters
SERRATIA
77
✿ Majority of S. rubidaea and some strains of S. marcescens,
S. plymuthica produce a non-water soluble ___________________________ pigment
red to pink pigment (prodigiosin)
78
serratia that produces a very musty, pungent odor
S. odorifera
79
All Serratia species are associated with __________________
NOSOCOMIAL
OUTBREAKS
80
All Serratia species produces _____________________ differentiates them from
other members of the tribe
extracellular DNAse
81
All serratia species are Slow LF and positive for ONPG, except:
Serratia fonticola
82
All serratia species _________________ to a wide range of antimicrobial agents
Resistance
83
✿ Most significant Serratia species
✿ causes nosocomial UTI, respiratory tract infection and
bacteremia in nurseries and cardiac surgery and burn units
SERRATIA MARSESCENS
84
SERRATIA MARSESCENS Biochemical test
❖ TSI: K/A or A/A
❖ IMVIC: - - + +
85
serratia that causes osteomyelitis following a motorcycle
accident
S. plymuthica
86
serratia that produces a very musty, pungent odor
resembling that of rotten potatoes. Isolated from sputum, blood
and urine
S. odorifera
87
3 Species of HAFNIA
Hafnia alveli
Hafnia paralvei
Hafnia psychrotoleranas
88
✿ Resembles Enterobacter but differentiated by its ability to
ferment lactose, sucrose, sorbitol and raffinose
✿ Differentiated from Serratia because it is DNAse and Lipase
(-)
HAFNIA
89
HAFNIA Major Characteristic: __________________
delayed (+) citrate rxn
90
✿ Considered as opportunistic pathogens
✿ widely disseminated in the environment and are normal
intestinal microbiota
PROTEUS SPP.
91
Distinguishing characteristic from other members of Enterobacterales
ability to deaminate the amino acid phenlalanine
92
PROTEUS SPP. none of the members ferment ________
lactose
93
PROTEUS SPP. 4 species
P. mirabilis
P. vulgaris
P. penneri
P. myxofaciens
94
PROTEUS SPP. human pathogens
✿ P. mirabilis and P. vulgaris
95
Urease (+) activity of P. mirabilis can lead to _______________________
struvite kidney stones (calculi)
96
✿ can produce swarming on SBA
✿ Has burnt-chocolate or burnt-gunpowder odor
“CHOCOLATE CAKE”
PROTEUS SPP.
97
✿ P. vulgaris and P. mirabilis can be differentiated by:
❖ Sucrose fermentation (+ P. vulgaris)
❖ Indole (+ P. vulgaris)
❖ Citrate ( + P. mirabilis)
❖ Ornithine decarboxylase (+ P. mirabilis)
98
CITROBACTER SPP. All grow on _________________
Simmons citrates medium
99
✿ Hydrolyze urea slowly; ferment lactose
✿ Considered inhabitants of the GI tract and are associated
with hospital-acquired infections (UT
CITROBACTER SPP
100
- CITROBACTER isolated in diarrheal stool cultures, associated
with UTI’s, pneumonia, intraabdominal abscesses, endocarditis
in IV drug abusers
C. freundii
101
- CITROBACTER that is the cause of nursery
outbreaks of neonatal meningitis and brain abscesses
C. koseri
102
CITROBACTER associated with community-acquired infectious
including septicemia with cervical cancer
C. braakii
103
✿ CITROBACTER Can be mistaken for ____________________ when isolated from stool
cultures
Salmonella
104
Differentiation of CITROBACTER and SALMONELLA
❖ C. freundii: +urease, -lysine decarboxylase
❖ Salmonella: -urease, +lysine decarboxylase
105
a PROVIDENCIA pathogen of the urinary tract and implicated in
diarrheal disease among travelers
P. rettgeri
105
- MORGANELLA that was the documented cause of UTI and neonatal
sepsis
M. morganii
105
MORGANELLA SPP. Motile bt ______________
does not swarm
106
PROVIDENCIA that is implicated in outbreaks in burn units and has bee
isolated from urine cultures
P. stuatii
107
PROVIDENCIA that is most commonly found in the feces of children with diarrhea; however, its role as a cause of diarrhea
has been proven
P. alcalifaciens
108
PROVIDENCIA rare isolate
P. rustigianii
109
PROVIDENCIA that is yet to be isolated from any clinical
specimen
P. heimbachae
110
EDWARDSIELLA SPP Biochemical Test
✿ Urea (-)
✿ Lysine Decarboxylase (+)
✿ H2S (+)
✿ Indole (+)
111
EDWARDSIELLA SPP Do not grow on ____________
Citrate
112
EDWARDSIELLA SPP. It biochemically resembles ____________, except Edwardsiella is ____________________________
E. coli, H2S positive and lactose negative
113
✿ Only OXIDASE-POSITIVE member of the Enterobacterales
PLESIOMONAS SPP.
114
A glucose fermenter, facultatively anaerobic, gram-negative
bacill
PLESIOMONAS SPP.
115
116
PLESIOMONAS SPP. is Susceptible to _________, does not have the ability to produce gas
agent O/129
117
- is the only species in PLESIOMONAS SPP.
P. shigelloides
118
✿ Emerged as a potential cause of enteric disease in humans
(after consumption of undercooked seafood or untreated
water)
PLESIOMONAS SPP.
119
The more common PLESIOMONAS SPP. disease lasts from _________ to _____________
14 days to 2-3 months
120
✿ Do not ferment lactose
✿ Do not grow on Potassium cyanide (KCN)
SALMONELLA SPP.
121
SALMONELLA SPP. Culture Characteristics
❖ MAC: non-lactose fermenters, NLF
❖ HE: Green, black center as a result of H2S production
❖ XLD: red with black center
❖ SSA: Colorless with black center
122
Virulence factors of SALMONELLA SPP.
fimbriae
antigenic structures
enterotoxin
123
allows the SALMONELLA SPP. the ability to traverse intestinal mucosa
fimbriae
124
Acute gastroenteritis or food poisoning most common
manifestation of _________________
salmonella
125
salmonella infective dose
10^6 bacteria
126
Antimicrobial of choice for salmonella
Chloramphenicol,
Ampicillin and
Trimethoprim-sulfamethoxazole
127
most severe form of enteric fever
Typhoid fever
128
Typhoid fever Caused by ________________ a milk
borne disease of cow
Salmonella Typhi
129
Typhoid fever 2nd week allows the appearance of _________
Rose Spots
130
only solution to the chronic state
of enteric carriers of salmonella
Cholecystectomy
131
gold standard
for the detection of Salmonella spp
Culture of Bone Marrow Aspirate
132
detects the presence of serum
agglutinins (antibodies to H and O) in patients serum with
suspected typhoid and paratyphoid fever
WIDAL TEST
133
High titer of H>(OR EQUAL TO) 1:160 suggests ________________________
past infection or immunization
134
✿ Resemble Escherichia coli but are non-lactose fermenter
SHIGELLA SPP.
135
✿ All Shigella spp. Can cause ____________________ Characterized by the presence of blood, mucus, and
pus in the stool
bacillary dysentery
136
SHIGELLA SPP. is named after ______________
Kiyoshu Shiga
137
_______________ are Susceptible to disinfectants and high concentrations of
acids and bile
SHIGELLA SPP.
138
Shigella spp. Can generally be differentiated from E.coli
based on:
❖ Inability to ferment lactose
❖ Lack of motility
❖ Negative indole reaction
139
✿ AKA: Bacillary dysentery
✿ Spread via fecal-oral route or through ingestion of
contaminated food and water
SHIGELLOSIS
140
SHIGELLOSIS Incubate for _______
1-7 days
141
SHIGELLOSIS Begin with fever, abdominal cramping and pain and diarrhea
accompanied by _____________
tenesmus
142
YERSINIA spp. that is the causative agent plague
Yersinia pestis
143
YERSINIA spp. associated with sporadic cases of gastroenteritis,
mesenteric lymphadenitis
Yersinia pseudotuberculosis and Y. enterocolitica
144
YERSINIA spp. that mimic appendicitis
Y. enterocolitica
145
YERSINIA spp. Exhibit “ __________” appearance under microscopy - show
marked bipolar staining when stained with “_________________”
safety pin, WAYSON STAIN
146
YERSINIA spp. Optimal growth is observed at ____________________, and growth is enhanced by continued
incubation at room temperature
25 degrees celsius to 30
degrees celsius
147
✿ Causative agent of plague, a disease primarily of rodents
✿ Class A bioterrorism agent
Yersinia spp.
148
yersinia with swollen lymph nodes
(buboes) in axillary and inguinal area
Bubonic (granular) form
149
yersinia with inhalation of organism
Pneumonic form
150
when yersinia bacteria spread to the
bloodstream
Septicemic form
151
✿ Can be acquired from contact with household pets
✿ Human infections most often occur after the ingestion of
contaminated food, often pork, and vacuum-packed deli meat,
beef, lamb, chicken, nd possibly chocolate milk and water
YERSINIA ENTEROCOLITICA
152
Associated with the transfusion of contaminated Packed
RBC’S
YERSINIA ENTEROCOLITICA
153
characterized by tender, red nodules
that may be accompanied by itching and burning and the areas
involved include the anterior portion of the legs; some patients
have reported nodules on their arms
Erythema nodosum
154
_________________________ is used to increase the
recovery in fecal samples suspected of Yersinia enterocolitica
Cold enrichment technique
155
Selective medium for YERSINIA ENTEROCOLITICA
Cefsulodin-irgasan-novobiocin agar
(CIN)
156
Colony Characteristic of YERSINIA ENTEROCOLITICA
Bull’s eye colonies (colonies
containing a central dark red/pink zone surrounded by an outer
translucent zone)
157
A yersinia pathogen primarily of rodents (guinea pigs)
YERSINIA PSEUDOTUBERCULOSIS
158
YERSINIA PSEUDOTUBERCULOSIS natural reservoir
birds
159
YERSINIA PSEUDOTUBERCULOSIS causes a disease characterized by caseous swellings called
__________________
pseudotubercles
