Chapter 19 Enterobacteriaceae

Question 1

What are the general characteristics of Enterobacteriaceae?

Answer 1

Ferment glucose
Reduce nitrate to nitrites
Oxidase negative

Question 1

What is the morphology of Enterobacteriaceae

Answer 1

Gram-negative coccobacilli or straight rods

Question 2

True or false. Enterobacteriaceae is facultatively anaerobic

Answer 2

True

Question 3

What is the macroscopic morphology of Enterobacteriaceae

Answer 3

Large moist, gray colonies

Question 4

Bile salts and crystal violet inhibit gram-positive
It is selective and differential
Lactose fermentation is differential
What agar plate is this?

Answer 4

MacConkey MAC agar

Question 5

Selective and differential
Methylene blue inhibits gram-positive
Lactose and sucrose fermentation is differential
What agar plate is this?

Answer 5

Eosin-methylene blue (EMB) agar

Question 6

Selective and differential
Bile salts inhibit gram-positive, some gram-negative
Lactose and sucrose fermentation is differential
What agar plate is this?

Answer 6

Hektoen enteric (HE)

Question 7

Green to blue color with H2S gas creating a black ppt is what type of enterobacteria

Answer 7

Salmonella on HE agar

Question 8

Green to blue green color is what type of enterobacteria

Answer 8

Shigella on HE agar plate

Question 9

Selective and differential
Has Sodium Deoxycholate
What type of agar plate is this?

Answer 9

Xylose lysine deoxycholate (XLD) agar

Question 10

Sodium Deoxycholate does what

Answer 10

Inhibits gram-positive and some gram-negative

Question 11

On the XLD agar plates, Escherichia coli and Citrobacter will produce what kind of colonies?

Answer 11

Yellow colonies

Question 12

Yellow colonies on the XLD agar means that fermenters of those not producing what?

Answer 12

lysine decarboxylase

Question 13

On XLD agar what kind of colonies will shigella produced?

Answer 13

Colorless or red colonies

Question 14

On XLD agar what colonies will Salmonella will produced

Answer 14

Red colonies with black centers

Question 15

What does adherence mean?

Answer 15

Prevent being removed from tissues

Question 16

Enterobacteriaceae has what type of antigens?

Answer 16

O antigen
H antigen
K antigen

Question 17

Where is the O antigen located at?

Answer 17

In the cell wall and it is the heat stable antigen

Question 18

H antigen is the what type of antigen?

Answer 18

Flagellar and it is heat stable

Question 19

K antigen is what type of antigen

Answer 19

Capsular antigen which is heat labile

Question 20

Dry pink colonies
Beta-hemolysis on blood agar plate (BAP)
Motile
Possess adhesive fimbriae and sex pili
Possess O, H, K antigen
is what type of Enterobacteriaceae

Answer 20

E.coli

Question 21

What is the most common cause of UTIs?

Answer 21

Uropathogenic E.coli

Question 22

Uropathogenic E.coli usually originate from where?

Answer 22

In the large intestine as normal flora

Question 23

What can cytolysins do

Answer 23

Kill immune cells and inhibit phagocytosis

Question 24

Klebsiella belong to what tribe

Answer 24

Klebsielleae

Question 25

Where can the tribe members be found at

Answer 25

In the intestinal tract of humans and animals, in soil, water, and plants

Question 26

Klebsiella pneimoniae can be in the

Answer 26

lower respiratory tract infection of hospitalized patients

Question 27

What is the virulence factor of klebsiella pneumoniae

Answer 27

polysaccharide capsule

Question 28

A documented pathogen causing meningitis and bacteremia in neonates from powdered infant formula

Answer 28

Cronobacter sakazakii

Question 29

Opportunistic pathogens associated with outbreaks in health care settings

Answer 29

serratia species

Question 30

What species is this of Serratia Pink-to-red pigment when growing at room temp Usually most clinically relevant Nosocomial infections of the Urinary tract, respiratory tract, and bacteremia

Answer 30

S. marcescens

Question 31

What type of species of Serratia is this? Dirty, musty odor resembling that of rotten potatoes

Answer 31

S. odorifera

Question 32

What type of bacteria is this? Linked to gastroenteritis and occasionally isolated from stool cultures

Answer 32

Hafnia alvei

Question 33

P. mirabilis and P. vulgaris generally produce swarming on what type of laboratory media. What kind of smell is produce

Answer 33

Burnt chocolate odor

Question 34

What Morganella species can cause UTI species, is a possible agent of diarrheal disease and cause of neonatal sepsis

Answer 34

M. morganii

Question 35

P.rettgeri can cause what type of outbreaks

Answer 35

Urinary tract pathogen and occasionally nosocomial outbreaks

Question 36

What is the most common citrobacter species

Answer 36

C. freundii

Question 37

What are three major clinical types of plesiomonas that cause gastroenteritis

Answer 37

Watery or secretory diarrhea Chronic disease that lasts from 14 days to 2-3 months Resembles colitis

Question 38

True of false- Plesiomonas is oxidase positive

Answer 38

True

Question 39

Is direct microscopic examination helpful in differentiating the species of enterobacteriaceae?

Answer 39

No it is not very helpful

Question 41

Characterized by prolonged fever and intermittent bacteremia

Answer 41

Nontyphoidal bacteremia

Question 42

This type of bacteria appear clear, colorless, nonlactose-fermenting on MAC and on HE or XLD and does not produce H2S

Answer 42

Shigella

Question 43

Lack H antigens, has K antigen and O antigens are separated by serologic grouping A through D

Answer 43

Shigella

Question 44

Most serious infection (developing countries) is what type of shigella species

Answer 44

S. dysenteriaae group A

Question 45

Second most common isolate in the United States is what type of shigella species

Answer 45

S. flexneri Group B

Question 46

This type of shigella is more common in developing countries

Answer 46

S. boydii (Group C)

Question 47

This type of shigella is most common isolate in the United States

Answer 47

S. sonnei Group D

Question 48

Shigella dysentery invade what type of tissues?

Answer 48

Colonic tissues

Question 49

What is the causative agent of plague?

Answer 49

Y. pestis

Question 50

Gram-negative coccobacilli resembling a safety pin appearance (bipolar staining)

Answer 50

Yersinia pestis

Question 51

This type of yersinia can be acquired from contact with swine, cats, and dogs.

Answer 51

Yersinia enterocolytica

Question 52

Gram-negative coccobacilli appearance (bipolar staining)

Answer 52

Y. enterocolytica

Question 53

This type of yersinia is the primary pathogen of rodents, farm animals, and birds

Answer 53

Yersinia pseudotuberculosis

Question 54

This type of media contains antimicrobials or chemicals

Answer 54

selective media

Question 55

This media allows differentiation of bacterial species based on colony morphology

Answer 55

Differential media