intro

Question 1

Bacteria characteristics

Answer 1

Prokaryotes
70s ribosome (30 s and 50 s)
nuclear area w/o a membrane
Plasmids-extra DNA that may have Abx resistant genes exchanged via transformation, transduction, conjugation
Complex inner membrane
Asexual division or binary fission

Question 2

Bacterial cell structure

Answer 2

Going from internal to external

1. Cell membrane
2. Periplasmic space
3. Cell wall
   * Gram Positive (purple)- Thick peptidoglycan with teichoic acid holding it together
   * Gram Negative(red)- Outer membrane with LPS and porins and a thin peptidoglycan layer
4. Accessory structures (Capsule)

Question 3

Cell wall

Answer 3

*Gram+
Thick layer of peptidoglycan (permeability barrier), with extensive crosslinking. No outer cell membrane, teichoic acid (membrane stabiity) Violet

*Gram-
Thin Layer of peptidoglycan, little crosslinking, outer membrane with porins (permeability barrier) has LPS
LPS- O-anigen is variable, Lipid A is a fever inducing endotoxin that stimulates PRRs
Red, and Periplasm has beta-lactamases

Question 4

Haemophilus influenza

Answer 4

Transmission from respiratory tract of active cases, carriers, and convalescent

Infection: uncomplicated colonization of nasopharynx, sinus middle ear or bronchi. w/ life threatening invastion of blood stream-> meninges

Virulence: 6 serotypes but only type B can cause meningitis bc of a polysaccharide capsule

Epidemiology: 3months to 3 yo

Vaccine 1st Gen: polysaccharide vaccine, poor memory
2nd Gen: PRP proten conjugate with Diptheria toxoid to generate T cell dependent Ab response with memory due to anti-capsule Ab

Question 5

aerobes

Answer 5

metabolize oxygen, grow only if oxygen is present (Pseudomonas and Tb)

Question 6

Facultative Anaerobes

Answer 6

metabolize oxygen in presence of oxygen, ferment in the absence of oxygen (Lactobacillus)

Question 7

Microaerophiles

Answer 7

Metabolize oxygen, grow only in low oxygen environments

Question 8

Aerotolerants

Answer 8

dont metabolize oxygen, but ferment regardless of its presence

Question 9

Anaerobes-

Answer 9

dont metabolize and do live in oxygen (Clostridium)

Question 10

Haemophilus

Answer 10

Transmission: from respiratory tract of active cases, carriers, covalescent

Infection: uncomplicated colonization of the nasopharynx, sinus, middle ear or bronchi. Life threatening infasion of blood stream that can cause meningitis

Virulence: 6 serotypes but type B causes meningitis due to polysaccharide capsule 3 months to 3 yrrs susceptible

Vaccine: 1st gen: polysaccharide vaccine (poor memory)
2nd gen: PRP protein conjugate with Diptheria toxoid to generate a T cell dependent antibody response to have memory.