Enterobacteriaceae (E.coli, Salmonella, Yersenia)🚽🤮 Flashcards

Overt pathogens of the gastrointestinal tract

1
Q

Lactose fermenters?

A

macConKEES

Citrobacter
Klebsiella
Escherichia
Enterobacter
Serratia

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2
Q

Enterobacteriaceae oxidase negative (except for ______ spp.)

A

Plesiomonas

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2
Q

All are catalase positive except

A

Shigella dysenteriae type 1

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3
Q

Antigenic classification

this is a heat-stable antigen located on the cell wall.

A

O antigen

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4
Q

Antigenic classification

this is a heat-labile antigen found on the surface of flagella, structures responsible for motility.

A

H antigen

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5
Q

Antigenic classification

this is a heat-labile polysaccharide found only in certain encapsulated species.

A

K antigen

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5
Q

K1 antigen is found on?

A

E. coli

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6
Q

Vi antigen is found on?

A

Salmonella enterica subsp. enterica serotype Typhi.

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7
Q

Primary marker of fecal contamination in water quality testing.

A

Escherichia coli

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8
Q

Antigenic classification of E.coli

A

O, H, and K antigens.

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8
Q
  • Ferments of glucose, lactose, trehalose, and xylose
A

E.coli

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9
Q

Lipid A portion of lipopolysaccharide (LPS). (toxin)

A

Endotoxin

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9
Q

strain of E. coli most common cause of UTIs in humans

A

UPEC

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10
Q

E. coli strain with PILI, CYTOLYSIN, AEROBACTIN

A

UPEC

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10
Q

allow bacterial cells to chelate iron

A

AEROBACTIN

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11
Q

kill immune cells and inhibit phagocytosis and
chemotaxis

A

CYTOLYSIN

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12
Q

5 major categories of E.coli

A

ETEC
EPEC
EIEC
EHEC
Enteroadherent - (DAEC & EAEC)

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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)

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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)

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15
Q

Traveler’s diarrhea a.k.a Montezuma’s revenge or La Tourista

A

ETEC: ENTEROTOXIGENIC E. coli

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16
Q

Infective dose of ETEC

A

10^6 to 10^10

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17
Q

Produces heat stable toxin similar to choleragen toxin from Vibrio cholera

A

ETEC

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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)

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19
Q

Stimulates guanylate cyclase:

which leads to hypersecretion of electrolytes and water into the intestinal lumen

A

Heat-stable Toxin (ST)

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20
Q
  • Infection: Dysentery-like/Shigella-like Infection; Water diarrhea with WBCs
  • Infective dose: >10^6
  • Direct transmission via fecal-oral route
A

EIEC: ENTEROINVASIVE E. coli

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21
Q

E coli strain. Produces dysentery with direct penetration, invasion and destruction of the intestinal mucosa

A

EIEC - ENTEROINVASIVE E. coli

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22
Q
  • 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
A

EPEC: ENTEROPATHOGENIC E. coli

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23
Q

Also known as Verotoxic E. coli (VTEC) / STEC

A

EHEC: ENTEROHEMORRHAGIC

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24
Q

Infection: Hemorrhagic colitis, HUS, Bloody diarrhea without WBC

  • Associated with ingestion of poorly cooked meats
A

EHEC

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25
Q

Produces SHIGA LIKE TOXIN

A

EHEC/EIEC

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26
Q

A toxin
Identical to Shiga toxin produced by S. dysenteriae Can be neutralized by antibodies to Shiga toxin

A

Verotoxin I

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27
Q

A toxin Biologically similar but immunologically different from Shiga toxin and Verotoxin I

A

Verotoxin II

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28
Q

Virulence factors of EHEC

A

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

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29
Q

Colorless on SMAC (sorbitol MacConkey Agar)

A

EHEC

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30
Q

What E. coli strain did Brianne Kinner suffer from?

Where did she get it from?

A

EHEC

Jack in the Box burger

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31
Q

serotype of EHEC associated with hemorrhagic diarrhea and HUS

A

0157:H7

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32
Q

E. coli IMViC reaction

A

++00

33
Q

E. coli TSI reaction

A

A/A (acid over acid)
- ferments glucose, sucrose/lactose
+gas, -h2s

34
Q

E. coli on LIA reaction

A

purple slant/yellow butt

meaning:
lysine decarboxylation (-)
negative for lysine decarbolyxation

35
Q

The most pathogenic enterobacteria for humans causing enteric fever and acute gastroenteritis

A

Salmonella spp.

36
Q

Disease caused by salmonella spp. resulting from bacterial invasion of the
bloodstream

A

enteric fever (typhoid)

37
Q

disease resulting from a foodborne infection/intoxication

A

acute gastroenteritis

38
Q

NOTE:
Salmonella

  • Habitat: inhabits GI Tract of animals
  • MOT:
  • Ingestion of contaminated animal food products or improperly cooked poultry, milk, eggs and dairy products
A

🫦

39
Q

was the cook who spread the typhoid during the 1900s that infected 51 individuals.

A

Mary Mallon (a.k.a Typhoid Mary)

40
Q

Salmonella are motile except:

A

S. gallinarum and S. pullorum)

41
Q

Salmonella spp. are encapsulated except:

A

S. typhi

42
Q

Antigenic structures of salmonella spp.

A

O,H,K-antigens

note: O-antigen is poorly immunogenic

43
Q

Green colonies with black center of HEA (Heaktoen-Enteric Agar)

A

Salmonella

44
Q

Red colonies with black centers on XLD (Xylose – Lysine – Deoxycholate)

A

Salmonella

45
Q

THREE (3) GENERAL CATEGORIES OF SALMONELLA INFECTION

A

I. Enteric fever
II. Gastroenteritis
III. Bacteremia

45
Q

NOTE:
Salmonella spp.

A

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
Q

causative agent:

Symptoms: malaise, anorexia, lethargy, myalgia and continuous frontal dull headache, “rose- spots” appear during the 2nd week of fever

A

S. typhi

47
Q

Complications of S. typhi

A

necrotizing cholecystitis and Peyer’s patches

48
Q

causative agent of peanut butter outbreak

A

S. sero. Typhimurium

49
Q

causative agent of Gastroenteritis: most common forms of food poisoning

A

Salmonella enterica subsp. Enterica

50
Q

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
A

Salmonella spp.

51
Q

Occurs with and without extraintestinal foci of infection caused by nontyphoidal Salmonella (S. Typhimurium, S. Paratyphi, and S. Cholerasuis)

  • Prolonged fever and intermittent bacteremia
A

Bacteremia

52
Q

two species of salmonella

A

S. enterica
S. bongori

53
Q

Within the S. enterica subsp. enterica (also called subspecies I) are 3 serotypes:

A
  • Salmonella serotype Typhi
  • Salmonella serotype Choleraesuis,
  • Salmonella serotype Paratyphi
54
Q

All salmonella spp. produce H2S except:

A

S. serotype Paratyphi A

55
Q

Salmonella spp. All produce gas except

A

S. serotype Gallinarum and S. serotype Typhi

56
Q

salmonella are non motile except

A

S. Pullorum and S. Gallinarum

Basta nag end ug rum

57
Q

Salmonella IMViC

A

IMViC: -+-+

58
Q

Salmonella typhi IMViC

A

IMViC: -+–

59
Q

Salmonella TSI

A

TSI: K/A + gas; with H2S

-serotype Typhi
(K/A, (-) gas, + H2S

60
Q

Specimen identification of salmonella per week

A
  • BLOOD – 1ST week of infection
  • STOOL – 2nd week of infection
  • URINE – 3rd week of infection
61
Q

Closely related to the genus Escherichia Intracellular organisms, non-motile

A

Shigella

62
Q

NOTE:
Shigella spp:

I. S. dysenteriae (Group A)
II. S. flexneri (Group B)
III. S. boydii (Group C)
IV. S. sonnei (Group D)

A

🫦

63
Q

MOT: (4 Fs) of SHIGELLA

A

4-Fs:

flies
fingers
food
feces

64
Q

Other name of S. dysenteriae

A

Shiga bacillus

65
Q

Other name of S. flexneri

A

Strong’s bacillus; Flexner’s bacilli

66
Q

AKA Boyd’s bacilli; Newcastle- Manchester’s bacilli

A

S. boydii

67
Q

AKA Sonne-Ducal bacilli

A

S. sonnei

68
Q

Overt entero with only O-antigen

A

Shigella

69
Q

Bacillary dysentery Causative agent

A

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
Q

Shigella IMViC and TSI

A

IMVIC reaction: v+–
TSI: K/A (-) gas; (-) H2S

71
Q
  • MAC – clear colonies
  • HEA – green colonies
A

Shigella… flexneri

72
Q

Causative agent of bubonic plague

A

Yersinia pestis

73
Q

ONLY ENTERICS that is transmitted to humans by the bite of an infected flea

A

Yersinia pestis

74
Q

(vector) of yersenia pestis

A

Xenopsylla cheopis

75
Q

NOTE: short, plump rod with “bipolar staining or closed safety pin appearance” using Wayson or Methylene Blue Stain

A

Yersenia pestis

76
Q
  • CULTURE
  • BAP: pinpoint colonies at 24 hours;
    rough cauliflower colonies at 48 hours
  • Broth: “stalactite pattern
A

Y. pestis

77
Q
  • Secondary to bubonic plague
  • MOT: Close contact with other victims
A

II. Pulmonary Plague

77
Q

Associated with high fever and painful inflammatory swelling of axilla and groin (buboes)
- MOT: bite of an infected flea

A

I. Bubonic Plague

77
Q

BIOCHEMICAL TESTS

IMVIC Reaction: (-+–)
(Shigella: V+–)

TSI: K/A (-) gas; (-) H2S

A

y. pestis

78
Q

Three (3) forms of Plague:

A

I. Bubonic Plague
II. Pulmonary Plague
III. Septicemic Plague

79
Q
  • Most commonly isolated species of Yersinia
A

Yersinia enterocolitica

80
Q

Causative agent of enterocolitis – waterborne gastroenteritis

A

Yersinia enterocolitica

81
Q

Motile at 22 degrees Celsius but not at 35 degrees Celsius

  • Requires Cold Enrichment Technique
  • Has ability to survive in cold temperature
A

Yersinia enterocolitica

82
Q

bull’s eye colonies at 48 hours on Cefsulodin-irgasan-novobiocin Agar (CIN)

A

Yersinia enterocolitica

83
Q

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
A

Yersinia pseudotuberculosis

84
Q

never back down never what?

A

n3v4r g4v3 uP