MT: ENTEROBACTERIACEAE Flashcards
(127 cards)
1
Q
Enterobacteriaceae is Motile (except ___ and ____)
A
Shigella and Klebsiella
2
Q
Enterobacteriaceae. Natural habitat in humans – gastrointestinal tract
referred to as “____” or “___”
A
“enteric bacilli” or “enterics”
3
Q
Enterobacteriaceae Cause ___ diseases
A
Gastrointestinal Tract
4
Q
Enterobacteriaceae. Important ANTIGENIC STRUCTURE
A
O: Outer membrane
H: Flagella
K: Capsule
Vi: Capsule of Salmonella
5
Q
Important ANTIGENIC STRUCTURE. somatic ; heat stable; endotoxic activity
A
O-antigens
6
Q
Important ANTIGENIC STRUCTURE. heat labile; Inhibits phagocytosis and the effects of serum antibody
A
K or capsular antigen
7
Q
Important ANTIGENIC STRUCTURE. heat labile
A
H antigens or flagellar antigens
8
Q
Important ANTIGENIC STRUCTURE. S. typhi; categorized as K Ag
A
Vi antigen
9
Q
A. Major Intestinal Pathogen
A
- Salmonella
- Shigella
- Yersinia
10
Q
Opportunistic Pathogens
A
- Citrobacter
- Edwardsiella
- Enterobacter
- Hafnia
- Klebsiella
- Morganella
- Proteus
- Providencia
- Serratia
11
Q
C. Opportunistic/Pathogenic
A
Escherichia
12
Q
Rapid Lactose Fermenter
A
Escherichia
Enterobacter
Klebsiella
13
Q
Late Lactose Fermenter
A
Salmonella arizona
Shigella sonnei
Serratia
Hafnia
Yersinia
Citrobacter
14
Q
Non Lactose Fermenter
A
Shigella (except sonnei)
Salmonella (except arizonae)
Proteus
Providencia
Morganella
Edwardsiella
15
Q
Enterobacteriaceae. Culture media :
A
MacConkey Agar and Blood Agar
Eosin-Methylene Blue
16
Q
Enterobacteriaceae. Culture media : (substitute for
MacConkey agar)
A
Eosin-Methylene Blue
17
Q
Culture Media. selective for Yersinia sps
A
Cefsulodin-Irgasan-Novobiocin (CIN)
18
Q
Culture Media. use for differentiation of Lactose from Non Lactose Fermenters
A
Eosin-Methylene Blue (EMB)
19
Q
Culture Media. enrichment broth to enhance isolation of enteric pathogens
A
Gr (-) Broth
20
Q
Culture Media used for isolation: for Salmonella and Shigella
A
Hektoen Enteric (HE) agar
21
Q
Culture Media. diff Lactose from non lactose fermenters
A
MacConkey
22
Q
A
23
Q
A
24
Q
Culture Media used for isolation. diff of Salmonella and Shigella
A
Salmonella-Shigella (SS)
25
Culture Media. use to enhance recovery of Salmonella and Shigella
Selenite broth
Tetrathionate broth:
26
Culture Media. use to isolate Salmonella and Shigella
and differentiate from other Enterobacteriaceae
Xylose-Lysine Desoxycholate (XLD)
27
Enterobacteriaceae
Colonial morphology in BLOOD AGAR PLATE
- Moist, smooth, gray colonies
28
Escherichia coli. Colonial morphology in BLOOD AGAR PLATE
convex, circular, smooth with distinct edges
29
Enterobacter. Colonial morphology in BLOOD AGAR PLATE
similar but somewhat more mucoid
30
Klebsiella. Colonial morphology in BLOOD AGAR PLATE.
large and very mucoid and tend to coalesce with prolonged incubation
31
Salmonella and Shigella .Colonial morphology in BLOOD AGAR PLATE
similar to Escherichia coli but do not ferment
lactose
32
Serratia. Colonial morphology in BLOOD AGAR PLATE
reddish orange
33
Edwardsiella. Colonial morphology in BLOOD AGAR PLATE
yellowish white
34
Proteus. Colonial morphology in BLOOD AGAR PLATE
“SWARMING” motility (wavelike appearance)
35
Enterobacteriaceae on __%
sheep blood agar - -Large, dull, grey, nonhemolytic colonies
5%
36
E.coli is a lactose fermenter that gives off smooth __ (color) colonies
pink
37
Klebsiella pneumoniae on ___ agar appears pink, large, glistening, and mucoid
MacConkey agar
38
Serratia marcescens produce smooth,
raised, circular (2 to 4 mm), and non-lactose
fermenting ___ to __ colonies
pink to red
39
– to distinguish morphologically
similar bacteria of Enterobacteriacea all of which ferment glucose to an acid end product
Triple Sugar Iron Agar
40
Triple Sugar Iron Agar Components: sugars?
Glucose, Lactose, Sucrose
41
Triple Sugar Iron Agar. Components
Glucose, Lactose, Sucrose
Beef Extract
Peptone
Phenol red
FeSO4
42
Triple Sugar Iron Agar. Component which serves as the pH indicator
Phenol red
43
Triple Sugar Iron Agar. Component which serves as the H2S indicator
FeSO4
44
Principle: Fermentation of SUGARS to produce acid and production of H2S (Black)
Triple Sugar Iron Test
45
Escherichia, Klebsiella, and Enterobacter. TSI reaction?
A/A H2S-
46
Salmonella, Proteus, and Citrobacter. TSI reaction?
K/A H2S+
47
Shigella, Providencia, Serratia, anaerogenic Escherichia coli. TSI reaction?
K/A H2S-
48
Pseudomonas, Alcaligenes. TSI reaction?
K/K H2S-
49
Citrobacter freundii
A/A H2S+
50
for the identification of lactose-
fermenting members of Enterobacteriaceae.
IMViC reactions
51
IMViC means
Indole test
Methyl red test
Voges Proskaeur test
Citrate utilization
52
Rapid Urease Producers
Proteus and Morganella
53
Weak urease producers
Klebsiella and some enterobacter
54
Deaminase reactions
Proteus, Providencia and Morganella
55
Enterobacteria that is nonmotile at 37C but motile at 22C
Yersinia enterocolitia
56
Nonmotile Enterobacteria
Shigella and Klebsiella
57
Most abundant facultative anaerobe in the colon, Ferments lactose
Escherichia coli
58
3 antigens of Escherichia coli
O - 150
H - 50
K - 90
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60
Escherichia coli
Important Virulent Factors
Pili
Capsule
Endotoxin
exotoxin (enterotoxin)
61
this strain of Escherichia coli causes traveler's disease
Enterotoxigenic (ETEC) E. coli
62
this strain of Escherichia coli does not ferment sorbitol (sugar alcohol), it causes bloody diarrhea (shigalite toxins)
EHEC strain: E. coli 0.157:H7
63
Structures responsible for systemic disease are the ___ and ___
capsule and endotoxin
64
E.coli. Lab Diagnosis on MacConkey agar
Lactose fermenters forming pink colonies
65
E.coli. Lab Diagnosis on EMB agar
Greenish sheen (Green metallic sheen)
66
E.coli. Lab Diagnosis. produces ___ from tryptophan
indole
67
E.coli. Lab Diagnosis. Uses ___ as its only source of carbon
acetate
68
E.coli. Lab Diagnosis. Ferments _____ (except E. coli 0.157:H7)
sorbitol
69
E. coli treatment. Uncomplicated UTI
Co trimoxazole
70
E. coli treatment. Complicated UTI and sepsis
Parenteral antibiotics (3rd gen cephalosporins with or without aminoglycosides)
71
E. coli treatment. Toxigenic/traveler's diarrhea
self-limited (no antibiotic, only fluid and electrolyte replacement)
72
More than 2200 serotypes based on O and H antigen. Subdivided into Groups A, B, C, etc. and 1,2,3 etc
Salmonella
73
Gram negative, encapsulated (Vi antigen),
nonsporulating rods
Motile gram-negative facultative anaerobes
Non-lactose fermenting
Resistant to bile salts
H2S producing
Salmonella
74
Salmonella subgroup that is isolated from humans and highly pathogenic for humans
Subgroup 1
75
Salmonella Subgroup 1 consists of?
Subgroup 1: S. typhi, S. paratyphi, S. choleraesuis, S.gallinarum
76
Clinical diseases of Salmonella
Gastroenteritis
Enteric Fever
Septicemia
77
Clinical Disease of Salmonella that exhibits Typhoid, Paratyphoid fever
Enteric Fever
78
Clinical Disease of Salmonella wherein Salmonella org disseminates into the
bloodstream; can be an intermediate stage of the infection
Septicemia
79
Most common form of Salmonella infection with major foodborne outbreaks and sporadic disease
Salmonella Gastroenteritis/Salmonellosis
80
Salmonellosis cause of infection?
poultry, eggs
81
Salmonellosis causes nausea, headache,
vomiting and profuse diarrhea with few leukocytes in the stools but rarely blood ____ after ingestion
8-48 hours
82
Salmonella Gastroenteritis/Salmonellosis. recovery within ___ days
2-3 days
83
Salmonella Gastroenteritis/Salmonellosis is caused by
S. enteritidis bioserotypes (e.g., S. typhimurium)
84
Salmonella. Enteric fever route of transmission
fecal-oral route
85
Salmonella. Enteric fever is gotten from ingestion of?
fecal-contaminated food or water
86
Salmonella. Enteric fever incubation period
10-14 days
87
Clinical disease of Salmonella. Assoc with the enlargement of Peyer’s Patches as a
result of the infiltration of mononuclear cell
Enteric Fever
88
Salmonella. Enteric Fever
Clinical Findings:
1. Fever extending up to 4 weeks
2. Diarrhea
3. Nausea and vomiting
4. Abdominal pain
5. “rose spots” on the abdomen (rare)
6. Hepatosplenomegaly
89
Salmonella. Enteric fever. 2 clinical forms:
1. Typhoid fever
2. Paratyphoid fever
90
one of the clinical forms of enteric fever that is Not only an intestinal infection but a
general invasion particularly the lymphatic
system
Typhoid fever
91
one of the clinical forms of enteric fever that is Relatively mild course with sudden chills but otherwise similar to a mild typhoid fever
Paratyphoid fever
92
one of the clinical forms of enteric fever that is most often milk borne and transmitted by carriers and predominant in younger age groups
Paratyphoid fever
93
causative agents of Paratyphoid fever
a. Salmonella paratyphi A – sewage contaminated food
b. Salmonella paratyphi B (Salmonella schottmulleri) – often in carriers
c. Salmonella paratyphi C (salmonella hirschfeldii) – tends to produce endocarditis
94
Paratyphoid fever. Complications
intestinal hemorrhage
perforation and peritonitis
splenic rupture
95
May occur as a sequelae of enteric fever or rarely from gastroenteritis or may have no intestinal focus
Characterized by rapid rise with spiking temperature
Septicemia
96
Septicemia. Signs and symptoms
pneumonia
meningitis
conjunctivitis
sinusitis
suppurative arthritis
pyelonephritis
97
Septicemia. Sources of infection
– food and drink contaminated
with salmonellae
water
milk and other dairy products (ice cream, cheese,custard)
shellfish
dried or frozen eggs
meats and meat products
recreational drugs
animal dyes
household pets
98
Salmonella Specimens
Blood – culture (1st week)
Bone marrow – culture
Urine – culture ( after 2nd week)
Stool – culture
99
Enrichment cultures of Salmonella
Selenite F broth
tetrathionate broth
100
Differential media of Salmonella
MacConkey
101
in Salmonella, what agar exhibits green with black centers (lactose negative; H2S positive)
Hektoen enteric agar
102
in Salmonella, what agar exhibits rapid detection of Salmonella typhi producing jet black colonies, black sheen or with
dotted black or greenish gray
Bismuth sulfite agar
103
104
Indirect agglutination test
qualitative and quantitative measures
Widal Test
105
Widal Test. POSITIVE: Antibody titer is ___
> 1:160
106
EIA for the rapid detection of
specific IgM and IgG antibodies (60min)
Typhidot Test
107
Four species of Shigella
Shigella sonnei
Shigella flexneri
Shigella boydii
Shigella dysenteriae
108
Shigella causes __ diarrhea
Watery diarrhea with fever; changing to dysentery.
109
This bacteria is the Major cause of bacillary dysentery (severe 2nd stage)
in pediatric age group (1-10 yrs) via fecal-oral route
Shigella
110
this bacteria : Invade the epithelial lining of the L. intestine 🡪
destruction and death of the epithelial cells 🡪
BLOODY DIARRHEA (DYSENTERY)
Shigella
111
Two stage disease of Shigella
Early stage
Second stage
112
Shigella. What stage? Watery diarrhea attributed to the enterotoxic activity of Shiga toxin following ingestion and noninvasive
colonization, multiplication, and production of enterotoxin in the small intestine
Fever attributed to neurotoxic activity of toxin
Early stage
113
Shigella. What stage? Adherence to and tissue invasion of large intestine
with typical symptoms of dysentery
Cytotoxic activity of Shiga toxin increases severity
Second stage
114
Shiga Toxin Effects in Shigellosis
1. Enterotoxic Effect
2. Cytotoxic Effect
3. Neurotoxic Effect
115
Shiga Toxin Effects in Shigellosis.
-Adheres to small intestine receptors
- Blocks absorption of electrolytes, glucose, and amino
acids from the intestinal lumen
Enterotoxic Effect
116
Shiga Toxin Effects in Shigellosis.
- B subunit of Shiga toxin binds host cell glycolipid
- A domain is internalized via endocytosis
- Causes irreversible inactivation of the 60S ribosomal subunit
Cytotoxic Effect
117
Clinical symptoms of Shigella
- Diarrhea, fever, nausea, vomiting, stomach cramps, and flatulence
- Stools may have blood, mucus, pus
118
Shigella. Specimen for culture
fresh stool, mucus flecks, rectal swab
119
Shigella. Specimen for serology
Serum
120
Shigella. Culture media with colorless colonies
EMB or MacConkey
121
Shigella. Culture media with colorless colonies without black centers
Salmonella-Shigella agar
122
Shigella. Culture media with green colonies without black center
Hektoen enteric agar
123
Once known as “Friedlander’s Bacillus”
Klebsiella pneumoniae
124
Klebsiella pneumoniae. Capsulated, mucoid colonies that tends to _____
“STRING”
125
Normal flora of the URT and GIT.
Most likely to be a primary non-opportunistic pathogen (related to its antiphagocytic capsule)
10% of healthy people are carriers
Klebsiella pneumoniae
126
Klebsiella pneumoniae Causes sever pneumonia 🡪 “____” like
sputum
“currant-jelly”
127
