I: Overview and Enteric Lab

Question 1

Gram Positive or Gram Negative? Endotoxin/LPS

Answer 1

Negative

Question 2

Gram Positive or Gram Negative? Outer membrane

Answer 2

Negative

Question 3

Gram Positive or Gram Negative? Teichoic Acids

Answer 3

Positive

Question 4

Gram Positive or Gram Negative? Thick Cell Wall

Answer 4

Positive

Question 5

Name four pathogens that are major contaminants of meat products.

Answer 5

Campylobacter jejuni, Salmonella, E. coli, Listeria monocytogenes

Question 6

Name the 4 Gram staining steps for a fixed bacterial smear.

Answer 6

Hucker’s crystal violet, Iodine, Decolorize, Safranin

Question 7

Name the toxin(s) of the pathogen: EHEC

Answer 7

Shigella-like toxin

Question 8

Name the toxin(s) of the pathogen: ETEC

Answer 8

Heat-stable enterotoxin, Cholera-like toxin

Question 9

Name two pathogens associated with dysentery.

Answer 9

Entamoeba histolytica, Shigella dysenteriae

Question 10

Name two pathogens that may be identified by curved or spiral shape on gram stain of a stool specimen.

Answer 10

Campylobacter jejuni, Vibrio cholerae

Question 11

On MacConkey agar, lactose(-) colonies appear ______.

Answer 11

Clear/Colorless

Question 12

On MacConkey agar, lactose(+) colonies appear ______.

Answer 12

Red

Question 13

Which E. coli presentation? Dysentery-like diarrhea, severe inflammation, fever

Answer 13

EIEC (Invasive)

Question 14

Which E. coli presentation? Pediatric diarrhea, hemorrhagic colitis, intense inflammatory response, can be complicated by Hemolytic-Uremic Syndrome

Answer 14

EHEC

Question 15

Which E. coli presentation? Persistent diarrhea in young children without inflammation or fever

Answer 15

EAEC (Aggregative)

Question 16

Which E. coli presentation? Usually infantile diarrhea, watery diarrhea with blood, some inflammation but no fever

Answer 16

EPEC (Pathogenic)

Question 17

Which E. coli presentation? Watery diarrhea in infants and travelers; no inflammation or fever

Answer 17

ETEC

Question 18

Which pathogen? Gram Negative Rods, Lactose(-), Oxidase(+)

Answer 18

Pseudomonas

Question 19

Which pathogen? Gram Negative Rods, Lactose(+), Indole(-)

Answer 19

Klebsiella, Enterobacter

Question 20

Which pathogen? Gram Negative Rods, Lactose(+), Indole(+)

Answer 20

E. coli

Question 21

Which pathogen? Gram Positive Cocci, Catalase(-), alpha-hemolysis

Answer 21

Streptococcus pneumoniae or viridans

Question 22

Which pathogen? Gram Positive Cocci, Catalase(-), beta-hemolysis

Answer 22

Group A, B, C, G Streptococcus

Question 23

Which pathogen? Gram Positive Cocci, Catalase(+), Coagulase(-)

Answer 23

Coagulase-Negative Staph (Epidermidis, saphrophyticus)

Question 24

Which pathogen? Gram Positive Cocci, Catalase(+), Coagulase(+)

Answer 24

Staph. Aureus

Question 25

Which pathogen? Gram-Negative Cocci

Answer 25

Neisseria, Moraxella

Question 26

Which pathogen? Large Gram Positive Rods

Answer 26

Clostridium

Question 27

Which pathogen? Non-staining due to lack of cell wall

Answer 27

Mycoplasma, Chlamydia

Question 28

Which pathogen? Small Gram Positive Rods

Answer 28

Listeria

Question 29

Which pathogens in the lab were capable of causing laboratory-acquired infection?

Answer 29

Salmonella typhinurium and enteritidis, and Campylobacter jejuni