Gram negative intro

Question 1

List characteristics of gram negative organisms

Answer 1

Periplasm
Outer membrane has LPS, a bioactive endotoxin
Thinner peptidoglycan layer with less cross linking
Serotyping: K- Kapsule antigen; O antigen is mostly LPS polysaccharide variants; H antigens are other things- flagella etc

Question 2

List enterobacteriaceae that cause sepsis

Answer 2

Escherichia, Klebsiella, Enterobacter, Proteus

Question 3

List enterobacteriaceae that cause pneumonia

Answer 3

Klebsiella, Serratia, Enterobacter, Escherichia

Question 4

List enterobacteriaceae that cause meningitis

Answer 4

Escherichia

Question 5

List enterobacteriaceae that cause UTI

Answer 5

Escherichia
Proteus- can be CA or nosocomial, causes struvite formation
Providencia- usually nosocomial in catheterized individuals

Question 6

List enterobacteriaceae that cause gastroenteritis

Answer 6

Salmonella, Shigella, Escherichia, Yersinia

Question 7

List four common virulence determinants

Answer 7

Adhesion
Host defense evasion
Nutrient acquisition
Mediators of host damage

Question 8

Neonatal meningitis is often caused by ___- encapsulated E coli

Answer 8

K1

Question 9

The K1 capsule is made up of ___________, which is also found on human cell surfaces, so humans do not make antibodies against i

Answer 9

sialic acid

“immunological tolerance”

Question 10

Pneumonia caused by _______ produced currant jelly sputum

Answer 10

Klebsiella