ENTEROBACTERIACEAE (primary pathogen)

Question 1

A family of organisms that include a lot of genera and spps.
- UBIQUITOUS ( can be found everywhere but COMMONLY present in LARGE INTESTINE
-non-spore forming
-gram negative
-facultative anaerobes
glucose fermenters, oxidase negative
-growth on BPA( blood plate agar); MacConkey to differentiate
-Catalase + , Oxidase - motile EXCEPT for shigella and Klebsiella

Answer 1

Enterobacteriaceae

Question 2

Major Structure of Enterobacteriaceae

Answer 2

cell wall
2 layers:
1. inner peptidoglycan
2. outer membrane

NOTE: generally, gram negative organisms has 2 layers

Question 3

use for the locomotion of the organisms

Answer 3

Flagella

Question 4

compose of cytoplasmic membrane , peptidoglycan layer and the outer membrane

Answer 4

Cell envelope

Question 5

has several proteins like

- LPS (lipoprotein saccharide)

Answer 5

Outer membrane

Question 6

• a heat stable
• O polysaccharide
• Core polysaccharide
• Lipid A

Answer 6

lipoprotein saccharide

Question 7

One of the most important protein component of your LPS

Answer 7

O polysaccharide

Question 8

What is the most remarkable, clinically significant component of your LPS

Answer 8

LIPID A

-responsible for producing fever and shock; inflammatory effect

Question 9

During serologic identification, what is being detected?

Answer 9

O polysaccharide

H protein

Question 10

use to know the subspecies, and sero- type of the organisms

Answer 10

Serologic Identification

Question 11

A protein that is found in encapsulated organisms

Answer 11

K antigen

Question 12

What is the function of Outer membrane in the cell wall?

Answer 12

• acts a a barrier to hydrophobic compounds and harmful substance
• acts as a sieve, allowing water-soluble molecules to enter through porins
• provides attachment sites that enhances attachment to the host cells.

Question 13

Virulence factor

Answer 13

• O antigen, or SOMATIC ANTIGEN, HEAT STABLE
• H antigen, or FLAGELLAR ANTIGEN, HEAT LABILE
• K antigen, or CAPSULAR ANTIGEN, HEAT LABILE
• LIPID A found in LPS

Question 14

Significance of Virulence factors

Answer 14

it enhance the ability to adhere, to colonize, to produce toxins, and invade host tissues.

Question 15

for MacConkey agar ( lactose fermenters and non-lactose fermenters)

Why does it turned pink for lactose fermenters?

Answer 15

because the organism is able to ferment lactose and it decreases pH turning it to acidic pH, and turning it to Pink in color.

Question 16

What is the main component of MacConkey agar

Answer 16

Bile salts and Lactose

Question 17

Inhibits the growth of the gram positive bacteria

Answer 17

Bile salts

Note: Indicator: crystal violet

Question 18

carbohydrate that causes the differentiation of the organisms

Answer 18

Lactose

Question 19

Opportunistic pathogens

Answer 19

found normally in gastrointestinal tract

and may cause disease

Question 20

primary pathogens

Answer 20

you can see it everywhere in your body and can cause disease

Question 21

What is the mode of transmission for Enterobacteriaceae?

Answer 21

Fecal- oral route

Question 22

Common infection of Enterobacteriaceae

Answer 22

• UTI (urinary track infection)
• gastroenteritis
• septicemia

Note: when not prevented may cause lethal results

Question 23

• Use to classify salmonella spp. base on their O, and H antigen
• Identifies each serotype as an individual salmonella sp.

Answer 23

Kaufmanns-White system

Question 24

the general steps of Kaufmanns- white system

Answer 24

if you can grow salmonella spps to your growth medium you will use polyvalent O antisera. a reagent that is a pool of different O antigens , if it is positive, there is agglutination and specific monovalent test should be done.

• in order for you to know the definite identification of the organism, you need to do serotyping and sero grouping.
• if consistent negative it is being boiled, because it could be your K antigen that is blocking your O antigen that is causing a false negative result

Question 25

Tribe 1 Escherichia

Answer 25

genus - 1. escherichia 2. Edwardsville 3. Citrobacter 4. salmonella 5. Shigella

Question 26

Tribe II; Klebsiella

Answer 26

Genus 1. Klebsiella 2. Enterobacter 3. Hafnia 4. Serratia

Question 27

Tribe III; Proteeae

Answer 27

Genus: 1. Proteus 2. Morganella 3. Providencia

Question 28

Tribe IV; Erwinieae

Answer 28

Genus: | 1. Erwinia

Question 29

Primary pathogens or True pathogens

Answer 29

Shigella spp, salmonella enterica, Yersinia sp.

Question 30

Characteristic: - they do not ferment lactose - gram negative - facultative anaerobic bacilli - in MacConkey agar they produce CLEAR or COLORLESS and non-lactose fermenting colonies - Indole (-), Voges- Proskauer (-)

Answer 30

Salmonella sp.

Question 31

Within the sp. of Salmonella enterica, there are 6 subsp.

Answer 31

1. Enterica (I) 2. Salamae (II) 3. arizone (IIIa) 4. diarizone (IIIb) 5. houtenae (IV) 6. indica (VI)

Question 32

Biochemical differentiation of selected numbers of the genus salmonella Salmonella Choleraesuis Salmonella Para typhi Salmonella typhi

Answer 32

``` Salmonella typhi -arabinose fermentation(-) -citrate utilization(-) it will not utilize citrate as form of energy source -glucose gas production (-) - H2S test (+) -glycine ``` ............

Question 33

What Enterobacteriaceae is highly Pathogenic

Answer 33

Salmonella | Shigella

Question 34

T/F Non fermenters produce colorless colonies on MacConkey medium

Answer 34

True

Question 35

T/F Lactose fermenter is also called Para colons

Answer 35

True

Question 36

T/F. Lactose fermenter organism appear as pink colonies (e.g. E. coli)

Answer 36

True

Question 37

T/F. Non-lactose fermenter organisms appear as COLORLESS colonies (e.g. Shigella)

Answer 37

True

Question 38

T/F. Detection of E.coli in water indicates pollution and contamination

Answer 38

TRUE

Question 39

- Gram negative, Straight rod - Grown in simple medium - Produce large grayish, Thick white, moist smooth opaque colonies - may contain capsule- - on MacConkey medium produce bright pink lactose fermenters

Answer 39

Escherichia coli

Question 40

What is the virulence factor of E.coli

Answer 40

Surface antigens and Toxins

Question 41

What diseases are caused by E. coli infection? 

Answer 41

Neonatal Meningitis | Gastroenteritis

Question 42

What are the classification of E. coli

Answer 42

- Enteropathogenic E.coli (EPEC) - Enteroinvasive (EIEC) - Enterotoxigenic (ETEC) - Enterohemorrhagic (EHEC) - Enteroaggregative (EAEC)

Question 43

What classification of E. coli causes diarrheal disease in children?

Answer 43

Enteropathogenic E.coli Note: brush border of the intestine is lost. poor hygiene predisposes, frequent in summer months

Question 44

What classification of E. coli is common and causes endemics in developing countries in all age groups? 

Answer 44

Enterotoxigenic E.coli Note: Causes travelers diarrhea

Question 45

What classification of E. coli produces mild diarrhea to frank dysentery?

Answer 45

Enteroinvasive E.coli Note: resembles shigella in many aspects, and they invade the intestinal epithelium

Question 46

What E. coli classification causes mild diarrhea which can lead to fatal hemorrhagic colitis and uremic syndrome?

Answer 46

Enterohemorrhagic E.coli

Question 47

What is the E. coli classification? They produce persistent diarrhea. -appear aggregated in stacked brick formation hep-2 cell

Answer 47

Enteroaggresive E. coli

Question 48

what is the leading cause of urinary tract infections which can lead to acute cystitis (bladder infection) and pyelonephritis (kidney infection)

Answer 48

E. coli