Ways to Identify Medically-Relevant Bacteria

Question 1

Ways in which bacteria can be identified 1) 2) 3) 4) 5) 6) 7) 8)

Answer 1

1) Microscopy 2) Culture 3) Proteomics 4) Genomics 5) Detection of structural antigens 6) Susceptibility to bacteriophages and bacteriocins 7) Production of toxins, other virulence determinants 8) Infecting animals

Question 2

Types of microscopy used to ID bacteria 1) 2)

Answer 2

1) Unstained (EG: darkground (syphilis), phase-contrast (cholera)) 2) Stained (Gram stain, Ziehl-Neelsen (acid-fast))

Question 3

How are proteomics data on bacteria generated?

Answer 3

Using mass-spectrometry

Question 4

Determinants of bacterial relatedness

Answer 4

Over 97% related rRNA -> Same species Over 95% related rRNA -> Same genera

Question 5

Core E. coli genome size

Answer 5

~2000 genes

Question 6

Average E. coli genome size

Answer 6

4000 - 6000 genes

Question 7

E. coli pangenome size

Answer 7

~20,000 genes

Question 8

Part of E. coli genome that determines specific subtypes

Answer 8

Accessory genome

Question 9

Ways in which bacteria can pick up new genes 1) 2) 3) 4) 5)

Answer 9

1) Plasmids 2) Transposons 3) Integrons 4) Bacteriophages 5) Pathogenicity islands

Question 10

Compound that gives bacterial cell wall shape and strength

Answer 10

Peptidoglycan

Question 11

G+ cell wall

Answer 11

Thick peptidoglycan layer overlying plasma membrane. Contains teichoic acids

Question 12

G- cell wall

Answer 12

Outer membrane surrounding thin peptidoglycan layer, which surrounds cell membrane

Question 13

Peptidoglycan structure

Answer 13

Question 14

What stabilises G- outer cell membrane?

Answer 14

LPS

Question 15

Colour of bacteria under G stain

Answer 15

G+ - Retain crystal violet in G stain (stain kinda blue) G- - Don’t retain crystal violet. Stain red/pink.

Question 16

Which type of bacteria more commonly have pili?

Answer 16

G-

Question 17

Classifications of bacterial metabolisms

Answer 17

1) Aerobic (final e- acceptor is oxygen) 2) Anaerobic (final e- acceptor is not oxygen) 3) Fermentation (final e- acceptor is an organic compound)

Question 18

Lipopolysaccharide structure

Answer 18