Microbiology

Question 1

Name the common intracellular bacteria?

Answer 1

Rickettsia
Chlamydia
Coxiella

Question 2

What bacteria can grow on artificial media but have no cell wall?

Answer 2

Mycoplasm

Ureaplasma

Question 3

Name the common spirochates?

Answer 3

Treponema
Leptospira
Borrella

Question 4

Name the common gram negative cocci?

Answer 4

Neisseria
Moraxella
Veillonella

Question 5

Name the anaerobic gram positive cocci?

Answer 5

Peptostreptococcus

Question 6

What type of bacteria are aerobic gram positive cocci in clusters?

Answer 6

Staphlococcus

Question 7

Are staphlococci catalase positive or negative?

Answer 7

Positive

Question 8

What type of bacteria are aerobic gram positive cocci in chains?

Answer 8

Streptococcus

Question 9

Are streptococci catalase positive or negative?

Answer 9

Negative

Question 10

Name an alpha-haemolytic gram positive cocci chain that is optochin sensitive?

Answer 10

Streptococcus pneumoniae

Question 11

Name an alpha-haemolytic gram positive cocci chain that isn’t optochin sensitive?

Answer 11

Viridans group streptococci

Question 12

What type of bacteria are aerobic gram positive cocci in clusters?

Answer 12

Staphlococcus

Question 13

Name a beta-haemolytic gram positive cocci chain?

Answer 13

Group A Strep (S. pyogenes)
Group B Strep (S. agalactiae)
Group G Strep ( S. dysgalactiae)

Question 14

Name a non-haemolytic gram positive cocci chain?

Answer 14

Group D Strep (S. bovis, Enterococcus spp.)

Question 15

Name a coagulase positive gram positive cocci in clusters?

Answer 15

Staphlococcus aureus

Question 16

Name a coagulase negative gram positive cocci in clusters?

Answer 16

Staphlococcus epidermidis

Staphlococcus saprophiticus

Question 17

Name a gram positive aerobic rod?

Answer 17

Corynebacterium
Listeria
Bacillus

Question 18

Name a gram positive anaerobic rod?

Answer 18

Clostridium

Propionibacterium

Question 19

Name a gram negative aerobic rod that is a lactose fermenter?

Answer 19

Escherichia

Klebsiella

Question 20

Name a gram negative aerobic rod that is not a lactose fermenter?

Answer 20

Salmonella
Shigella
Proteus
Pseudomonas (it is oxidase positive)

Question 21

Name a gram negative aerobic rod that is not a lactose fermenter or lactose fermenter?

Answer 21

Vibrio
Camplyobacter
Helicobacter
Haemophilus
Bordatella
Legionella

Question 22

Name a gram negative anaerobic rod?

Answer 22

Bacteroides

Question 23

What are Zeihl-Neelsen/Acid fast positive?

Answer 23

Mycobacteria - rods

Question 24

Name some MTB complex Ziehl-Neelsen positive?

Answer 24

Mycobacterium tuberculosis
Mycobacterium bovis
Mycobacterium africanum

Question 25

Name some non-tuberculous mycobacterium Ziehl-Neelsen positive?

Answer 25

``` Mycobacterium avium Mycobacterium kansasii Mycobacterium marinum Mycobacterium ulcerans Mycobacterium fortuitum etc. ```

Question 26

Name a Ziehl-Neelsen positive non-cultivable?

Answer 26

Mycobacterium leprae

Question 27

What colour is a stained gram positive?

Answer 27

Purple

Question 28

What colour is a stained gram negative?

Answer 28

Pink

Question 29

How would you carry out a gram stain?

Answer 29

Fixation --> crystal violet stain --> iodine treatment --> decolourisation --> counter stain (safranin)

Question 30

In what year was the great plague of London?

Answer 30

1334 spread from China

Question 31

In what year was the Mexico smallpox epidemic?

Answer 31

1519

Question 32

In what year was the great flu epidemic?

Answer 32

1918

Question 33

In what year was HIV identified?

Answer 33

1984

Question 34

In what year was severe acute respiratory syndrome (SARS) identified?

Answer 34

2003

Question 35

When was the global H1N1 flu pandemic?

Answer 35

2009 | Swine flu, type A influenza

Question 36

What is a pathogen?

Answer 36

An organism that causes or is capable of causing disease

Question 37

What is a commensal?

Answer 37

An organism which colonises the host but causes no disease in normal circumstances/

Question 38

What is an opportunistic pathogen?

Answer 38

A microbe that only causes disease if host defences are compromised.

Question 39

What is virulence/pathogenicity/

Answer 39

The degree to which a given organism is pathogenic.

Question 40

What is asymptomatic carriage?

Answer 40

When a pathogen is carried harmlessly at a tissue site where it causes no disease.

Question 41

What is the difference between gram positive and gram negative bacteria?

Answer 41

Gram negative have two membranes (inner and outer) while gram positive only have the outer. Gram positive have much more peptidoglycan.

Question 42

What is endotoxin?

Answer 42

Component of the outer membrane of bacterial eg. lipopolysaccharide in gram negative bacteria

Question 43

What is exotoxin?

Answer 43

Secreted proteins of gram positive and gram negative bacteria.

Question 44

Compare endo and exotoxin?

Answer 44

``` Composition: Exo - protein. Endo - lipopolysaccharide Action: Exo = specific. Endo = non-specific Heat effect: Exo = labile. Endo = stable Antigenicity: Exo = strong. Endo = weak Produced by: Exo = gram positive mostly. Endo = LPS gram negative Converted to toxoid: Exo = yes. Endo = no ```

Question 45

What are the 3 types of gene transfer in bacteria?

Answer 45

Transformation eg. via plasmid Transduction eg. via phage Conjugation eg. via sex pilus

Question 46

What is haemolysis?

Answer 46

Ability of bacteria to break down RBCs in blood agar - requires expression of hemolysin.

Question 47

What is alpha haemolysis and how does it present?

Answer 47

Caused by production of hydrogen peroxide oxidising haemoglobin to methemoglobin. Agar apears green.

Question 48

What is beta haemolysis and how does it present?

Answer 48

Lysis of RBS by hemolysin. Large clear areas around the bacteria.

Question 49

What is gamma haemolysis?

Answer 49

No haemolysis.