Gram Negative Bacteria

Question 1

What is the Structure of the Gram Positive Bacteria

Wall?

Answer 1

A thick peptidoglycan wall which stains purple on gram staining as it retains the dye very well.
Only 1 membrane: Cytoplasmic Membrane
Also contains Polysaccharides.

Question 2

What is the Structure of the Gram Negative Bacteria Wall?

Answer 2

A thin Peptidoglycan wall which stains pink as it does not retain the dye as well in gram staining.
Has 2 Membranes: Outer Membrane and Inner Cytoplasmic Membrane.
Also contains Lipopolysaccharides and Porins.

Question 3

What are Aerobes?

Answer 3

Bacteria which grow in Oxygen-Rich environments

Question 4

What are Anaerobes?

Answer 4

Bacteria which grow in Oxygen-Void environments

Question 5

What is the difference between a Strict Aerobe and an Aerobe?

Answer 5

Aerobes can switch to Anaerobic Respiration in the absence of oxygen.
Strict Aerobes die.

Question 6

What is the difference between a Strict Anaerobe and an Anaerobe?

Answer 6

Anaerobes can still grow in the presence of oxygen (although not as well)
Strict Anaerobes die in the presence of oxygen.

Question 7

Give examples of Strict Aerobe Bacilli

Answer 7

Legionella species

Pseudomonas Aeruginosa

Question 8

Give examples of Aerobic Cocci

Answer 8

Neisseria Gonorrhoea

Neisseria Meningitis

Question 9

How are Gram Negative Aerobic Bacilli divided?

Answer 9

Small Bacilli and Large Bacilli

Question 10

Give examples of Small Aerobic Bacilli

Answer 10

Bordetella Pertussis (causes Whooping Cough)
H. Influenzae

Question 11

Give examples of Large Aerobic Bacilli (Coliforms)

Answer 11

E.coli 
Klebsiella species
Proteus species 
Salmonella species 
Shigella species
E.coli 0157

Question 12

Which Coliforms are Gut Commensals?

Answer 12

E.coli
Klebsiella species
Proteus species

Question 13

Which Coliforms are Gut Pathogens?

Answer 13

Salmonella species
Shigella species
E.coli 0157

Question 14

What are Microaerophilic Bacteria?

What shape are they?

Answer 14

These bacteria need oxygen for respiration but can die from oxygen poisoning if oxygen levels get too high (extremely sensitive).
Bacilli shaped.

Question 15

Give an example of a Microaerophilic Small Curved Bacilli

Answer 15

Campylobacter species

Question 16

Give an example of a Microaerophilic Spiral Bacilli

Answer 16

Helicobacter species

Question 17

Give an example of Strict Anaerobic Bacilli

Answer 17

Bacteroides

Another gut commensal but can also cause wound infection

Question 18

How are Spiral-Shaped Bacteria Categorised?

Answer 18

Spirochete (longer and more flexible due to flagellum component)
Spirilla (shorter and more rigid)

Question 19

Give examples of Spirochete Bacteria

Answer 19

Leptospira
Borrelia
Spirochaeta

Question 20

What Gram Negative Bacteria make up the Enterobacteriaceae family?

Answer 20

E.coli species and other Coliforms
Pseudomonas species
Haemophilus species

Question 21

What Agar is used for Haemophilus?

Answer 21

Chocolate Agar

Question 22

What Gram Negative Bacteria is associated with Lukewarm Aerolised Water and Spain?

Answer 22

Legionella species

Common in Male Smokers, COPD Sufferers and Diabetics

Question 23

What Gram Negative Bacteria are commonly encountered in Sepsis?

Answer 23

Klebsiella species
Enterobacter species 
Pseudomonas species 
Neisseria Meningitis 
E.coli 0157

Question 24

How is Pseudomonas Aeruginosa treated?

Answer 24

Gentamicin

Long-term Ceftazidime or Cefepime if resistant to Gentamicin