Enterobacteriaceae (E.coli, Salmonella, Yersenia)🚽🤮 Flashcards
Overt pathogens of the gastrointestinal tract (92 cards)
1
Q
Lactose fermenters?
A
macConKEES
Citrobacter
Klebsiella
Escherichia
Enterobacter
Serratia
2
Q
Enterobacteriaceae oxidase negative (except for ______ spp.)
A
Plesiomonas
2
Q
All are catalase positive except
A
Shigella dysenteriae type 1
3
Q
Antigenic classification
this is a heat-stable antigen located on the cell wall.
A
O antigen
4
Q
Antigenic classification
this is a heat-labile antigen found on the surface of flagella, structures responsible for motility.
A
H antigen
5
Q
Antigenic classification
this is a heat-labile polysaccharide found only in certain encapsulated species.
A
K antigen
5
Q
K1 antigen is found on?
A
E. coli
6
Q
Vi antigen is found on?
A
Salmonella enterica subsp. enterica serotype Typhi.
7
Q
Primary marker of fecal contamination in water quality testing.
A
Escherichia coli
8
Q
Antigenic classification of E.coli
A
O, H, and K antigens.
8
Q
- Ferments of glucose, lactose, trehalose, and xylose
A
E.coli
9
Q
Lipid A portion of lipopolysaccharide (LPS). (toxin)
A
Endotoxin
9
Q
strain of E. coli most common cause of UTIs in humans
A
UPEC
10
Q
E. coli strain with PILI, CYTOLYSIN, AEROBACTIN
A
UPEC
10
Q
allow bacterial cells to chelate iron
A
AEROBACTIN
11
Q
kill immune cells and inhibit phagocytosis and
chemotaxis
A
CYTOLYSIN
12
Q
5 major categories of E.coli
A
ETEC
EPEC
EIEC
EHEC
Enteroadherent - (DAEC & EAEC)
13
Q
What type of Enteroadherent E.coli
- Associated with both UTI and GIT infections
- Causes cystitis in children and acute pyelonephritis in pregnant women
A
DAEC (Diffusely Adherent E. coli)
14
Q
- Causes diarrhea by adhering to the surface of intestinal mucosa
- Adheres to HEp2 cells, packed in a “stacked-brick” pattern
A
EAEC (Enteroaggregative E. coli)
15
Q
Traveler’s diarrhea a.k.a Montezuma’s revenge or La Tourista
A
ETEC: ENTEROTOXIGENIC E. coli
16
Q
Infective dose of ETEC
A
10^6 to 10^10
17
Q
Produces heat stable toxin similar to choleragen toxin from Vibrio cholera
A
ETEC
18
Q
ETEC strain
Activates adenylate cyclase:
hypersecretion of both electrolytes and fluids into the intestinal lumen leading to water diarrhea
A
Heat-labile Toxin (LT)
19
Q
Stimulates guanylate cyclase:
which leads to hypersecretion of electrolytes and water into the intestinal lumen
A
Heat-stable Toxin (ST)
20
- Infection: Dysentery-like/Shigella-like Infection; Water diarrhea with WBCs
- Infective dose: >10^6
- Direct transmission via fecal-oral route
EIEC: ENTEROINVASIVE E. coli
21
E coli strain. Produces dysentery with direct penetration, invasion and destruction of the intestinal mucosa
EIEC - ENTEROINVASIVE E. coli
22
- Infection: Infantile Diarrhea
- Stool typically contains large amount of mucus but apparent blood is not
present
- Lacked the toxins of ETEC and lacks the invasiveness of EIEC
EPEC: ENTEROPATHOGENIC E. coli
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Also known as Verotoxic E. coli (VTEC) / STEC
EHEC: ENTEROHEMORRHAGIC
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Infection: Hemorrhagic colitis, HUS, Bloody diarrhea without WBC
- Associated with ingestion of poorly cooked meats
EHEC
25
Produces SHIGA LIKE TOXIN
EHEC/EIEC
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A toxin
Identical to Shiga toxin produced by S. dysenteriae Can be neutralized by antibodies to Shiga toxin
Verotoxin I
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A toxin Biologically similar but immunologically different from Shiga toxin and Verotoxin I
Verotoxin II
28
Virulence factors of EHEC
Verotixon I
- (identical to shiga like toxin, can be neutralized with antibodies to shiga toxin)
Verotoxin II
- biologically similar but immunologically different from shiga toxin and verotoxin 1
29
Colorless on SMAC (sorbitol MacConkey Agar)
EHEC
30
What E. coli strain did Brianne Kinner suffer from?
Where did she get it from?
EHEC
Jack in the Box burger
31
serotype of EHEC associated with hemorrhagic diarrhea and HUS
0157:H7
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E. coli IMViC reaction
++00
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E. coli TSI reaction
A/A (acid over acid)
- ferments glucose, sucrose/lactose
+gas, -h2s
34
E. coli on LIA reaction
purple slant/yellow butt
meaning:
lysine decarboxylation (-)
negative for lysine decarbolyxation
35
The most pathogenic enterobacteria for humans causing enteric fever and acute gastroenteritis
Salmonella spp.
36
Disease caused by salmonella spp. resulting from bacterial invasion of the
bloodstream
enteric fever (typhoid)
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disease resulting from a foodborne infection/intoxication
acute gastroenteritis
38
NOTE:
Salmonella
* Habitat: inhabits GI Tract of animals
* MOT:
- Ingestion of contaminated animal food products or improperly cooked poultry, milk, eggs and dairy products
🫦
39
was the cook who spread the typhoid during the 1900s that infected 51 individuals.
Mary Mallon (a.k.a Typhoid Mary)
40
Salmonella are motile except:
S. gallinarum and S. pullorum)
41
Salmonella spp. are encapsulated except:
S. typhi
42
Antigenic structures of salmonella spp.
O,H,K-antigens
note: O-antigen is poorly immunogenic
43
Green colonies with black center of HEA (Heaktoen-Enteric Agar)
Salmonella
44
Red colonies with black centers on XLD (Xylose – Lysine – Deoxycholate)
Salmonella
45
THREE (3) GENERAL CATEGORIES OF SALMONELLA INFECTION
I. Enteric fever
II. Gastroenteritis
III. Bacteremia
45
NOTE:
Salmonella spp.
I. Enteric fever
* Typhoid fever
* Causative agent: S. typhi
* MOT: Ingestion of contaminated food originating from infected individuals or carriers; direct transmission through fomites is also possible
46
causative agent:
Symptoms: malaise, anorexia, lethargy, myalgia and continuous frontal dull headache, “rose- spots” appear during the 2nd week of fever
S. typhi
47
Complications of S. typhi
necrotizing cholecystitis and Peyer’s patches
48
causative agent of peanut butter outbreak
S. sero. Typhimurium
49
causative agent of Gastroenteritis: most common forms of food poisoning
Salmonella enterica subsp. Enterica
50
MOT: Used of contaminated cooking utensils that can spread the bacteria to other food and inadequate refrigeration
- Sources of infection: Poultry, dairy products and handling of pets
- Infective dose: 10^6 bacteria cells
- Symptoms: nausea, vomiting, chills, watery diarrhea and chills
Salmonella spp.
51
Occurs with and without extraintestinal foci of infection caused by nontyphoidal Salmonella (S. Typhimurium, S. Paratyphi, and S. Cholerasuis)
- Prolonged fever and intermittent bacteremia
Bacteremia
52
two species of salmonella
S. enterica
S. bongori
53
Within the S. enterica subsp. enterica (also called subspecies I) are 3 serotypes:
* Salmonella serotype Typhi
* Salmonella serotype Choleraesuis,
* Salmonella serotype Paratyphi
54
All salmonella spp. produce H2S except:
S. serotype Paratyphi A
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Salmonella spp. All produce gas except
S. serotype Gallinarum and S. serotype Typhi
56
salmonella are non motile except
S. Pullorum and S. Gallinarum
Basta nag end ug rum
57
Salmonella IMViC
IMViC: -+-+
58
Salmonella typhi IMViC
IMViC: -+--
59
Salmonella TSI
TSI: K/A + gas; with H2S
-serotype Typhi
(K/A, (-) gas, + H2S
60
Specimen identification of salmonella per week
* BLOOD – 1ST week of infection
* STOOL – 2nd week of infection
* URINE – 3rd week of infection
61
Closely related to the genus Escherichia Intracellular organisms, non-motile
Shigella
62
NOTE:
Shigella spp:
I. S. dysenteriae (Group A)
II. S. flexneri (Group B)
III. S. boydii (Group C)
IV. S. sonnei (Group D)
🫦
63
MOT: (4 Fs) of SHIGELLA
4-Fs:
flies
fingers
food
feces
64
Other name of S. dysenteriae
Shiga bacillus
65
Other name of S. flexneri
Strong’s bacillus; Flexner’s bacilli
66
AKA Boyd’s bacilli; Newcastle- Manchester’s bacilli
S. boydii
67
AKA Sonne-Ducal bacilli
S. sonnei
68
Overt entero with only O-antigen
Shigella
69
Bacillary dysentery Causative agent
Shigella dysenteriae type I
- Characterized by: acute inflammatory colitis and boody diarhhea (blood, mucus and WBCs in stool)
- Highly communicable - <200 bacilli
- Source of infection: Human carrier
- Transmission: fecal-oral route, person-to-person
70
Shigella IMViC and TSI
IMVIC reaction: v+--
TSI: K/A (-) gas; (-) H2S
71
* MAC – clear colonies
* HEA – green colonies
Shigella... flexneri
72
Causative agent of bubonic plague
Yersinia pestis
73
ONLY ENTERICS that is transmitted to humans by the bite of an infected flea
Yersinia pestis
74
(vector) of yersenia pestis
Xenopsylla cheopis
75
NOTE: short, plump rod with “bipolar staining or closed safety pin appearance” using Wayson or Methylene Blue Stain
Yersenia pestis
76
* CULTURE
- BAP: pinpoint colonies at 24 hours;
rough cauliflower colonies at 48 hours
- Broth: “stalactite pattern
Y. pestis
77
- Secondary to bubonic plague
- MOT: Close contact with other victims
II. Pulmonary Plague
77
Associated with high fever and painful inflammatory swelling of axilla and groin (buboes)
- MOT: bite of an infected flea
I. Bubonic Plague
77
BIOCHEMICAL TESTS
IMVIC Reaction: (-+--)
(Shigella: V+--)
TSI: K/A (-) gas; (-) H2S
y. pestis
78
Three (3) forms of Plague:
I. Bubonic Plague
II. Pulmonary Plague
III. Septicemic Plague
79
* Most commonly isolated species of Yersinia
Yersinia enterocolitica
80
Causative agent of enterocolitis – waterborne gastroenteritis
Yersinia enterocolitica
81
Motile at 22 degrees Celsius but not at 35 degrees Celsius
* Requires Cold Enrichment Technique
* Has ability to survive in cold temperature
Yersinia enterocolitica
82
bull’s eye colonies at 48 hours on Cefsulodin-irgasan-novobiocin Agar (CIN)
Yersinia enterocolitica
83
Identify the bacteria
* Pathogen of the rodents, particular guinea pigs
* Reservoir: farm and domestic animals (birds)
* MOT: close contact with the infected animals or their fecal material; ingestion of contamination food
* Motile at 18-25 degrees Celsius
* Urease +; ferments rhamnose
Yersinia pseudotuberculosis
84
never back down never what?
n3v4r g4v3 uP
