Gram -ve rods

Question 1

What are the different groups in the gram negative rods?

Answer 1

1. Enteric bacteria - enterobacteriaceae
2. Non-fermenters
3. Unusual gram-negative bacilli (UBs)

Question 2

The unusual gram negative bacilli correspond to _____% of clinical isolates and they are often ________.

Answer 2

<1%

zoonoses

Question 3

How many species are there in the enterobacteriaceae?

Answer 3

~120 species, all closely related

Question 4

Describe the morphology of the enterobacteriaceae.

Answer 4

Straight rods

Question 5

80-95% of all isolates from a clinical setting of enterobacteriaceae will be what organisms?

Answer 5

E. coli
Klebsiella pneumoniae
Proteus mirabilis

Question 6

> 99% of enterobacteriaceae clinical isolates belong to ____ species.

Answer 6

23

Question 7

What are the four cardinal characteristics of the enterobacteraceae?

Answer 7

1. Ferment glucose
2. Reduce nitrates to nitrites
3. Cytochrome oxidase negative
4. Flagella, if present, are peritrichous (one exception)

Question 8

The enterobacteriaceae are normal flora where?

Answer 8

mouth, oropharynx, genitalia, distal urethra, large bowel

Question 9

Where do the enterobacteriaceae live outside of the human body?

Answer 9

Soil or water

Question 10

All the enterobacteriaceae have the potential to become what?

Answer 10

opportunistic pathogens

Question 11

What are the different opportunistic infections that can be caused by the enterobacteriaceae?

Answer 11

UTIs, wound infections, pneumonia, meningitis, sepsis

Question 12

Meningitis due to opportunistic enterobacteriaceae are most common in what individuals?
Why?

Answer 12

neonates (poorly developed BBB) and patients post-neurosurgery

Question 13

The enterobacteriaceae basically live anywhere on the body that is _______.

Answer 13

moist

Question 14

If anyone asks what a pathogen does what is the best answer?

Answer 14

Sepsis and endocarditis - almost anything has the potential to cause this

Question 15

What is the only shared determinant of pathogenicity among the enterobacteriaceae?

Answer 15

LPS

Question 16

What are the three groups of Escherischia coli?

Answer 16

Commensals, enteric pathogens and extraintestinal infections

Question 17

E. coli is the most common cause of what?

Answer 17

UTIs

Question 18

E. coli strains are typed using what three antigens?

Answer 18

O antigen - LPS
H - antigen - flagella
K antigen - capsule

Question 19

When two DISSIMILAR organisms occupy the same ecological niche or live in close association with one another

Answer 19

symbiosis

Question 20

Any infection is considered this type of symbiotic relationship.

Answer 20

Parasitic

Question 21

What is the quickest way to differentiate between different E. coli strains?

Answer 21

Antibiograms

Question 22

periodic summary of antimicrobial susceptibilities of local bacterial isolates submitted to the hospital’s clinical microbiology laboratory

Answer 22

antibiogram

Question 23

This bacterium is a major cause of traveler’s diarrhea.

Answer 23

Enterotoxigenic E. coli - ETEC

Question 24

What are the three toxins of ETEC?

Answer 24

LT - similar to cholera toxin
STa
STb

Question 25

What is the difference between LT and ST toxins?

Answer 25

LT is heat labile

ST is heat stable

Question 26

How is LT similar to cholera toxin? Different?

Answer 26

Reacts with it immunologically but is not as potent

Question 27

What signs does enteroinvasive E. coli cause?

Answer 27

Bloody diarrhea

Fever

Question 28

Cultured cell line that originated from African green monkeys.

Answer 28

Vero cells

Question 29

Where do people acquired VTEC from?

Answer 29

undercooked hamburger, unpasteurized milk, water

Question 30

What does VTEC stand for? What is another name?

Answer 30

Verotoxigenic E. coli

aka Enterohemorrhagic E. coli (EHEC)

Question 31

What type of E. coli caused the Walkerton E. coli outbreak?

Answer 31

Verotoxigenic E. coli

Question 32

What does VTEC cause?

Answer 32

Bloody diarrhea and hemolytic uremic syndrome

Question 33

Hemolytic uremic syndrome is most common in what individuals?

Answer 33

Children under 5

Question 34

What is contraindicated for VTEC? Why?

Answer 34

antibiotics - increases changes of getting hemolytic uremic syndrome

Question 35

Where is salmonella enterica spp. enterica mostly found?

Answer 35

Food (poultry, eggs), water, pet turtles, African Dwarf frogs

Question 36

What does salmonella enterica spp. enterica cause?

Answer 36

Diarrhea, extraintestinal disease

Question 37

What is contraindicated for salmonella enterica spp. enterica? Why?

Answer 37

Antibiotics are contraindicated b/c using them increases the likelihood of becoming a chronic carrier and increases the length of the problem

Question 38

Where does one acquire salmonella enterica spp. enterica serovar Typhi from?

Answer 38

Food and water contaminated by human waste

Question 39

How long does an illness caused by salmonella enterica spp. enterica serovar typhi last?

Answer 39

3-5 weeks

Question 40

What does salmonella enterica spp. enterica serovar typhi cause?

Answer 40

enteric fever, headache, prostration, rose spots, initial constipation with later diarrhea

Question 41

If typhoid fever is caused, what is contraindicated?

Answer 41

Nothing, antibiotics should be used

Question 42

what is prostration?

Answer 42

Being extremely weak - too weak to get up

Question 43

How is typhoid fever diagnosed?

Answer 43

By isolation from blood, later from stools