Organisms

Question 1

Virulence

Answer 1

the capacity of a microbe to cause damage to its host

Question 2

Pathogen

Answer 2

a harmful organism that produces a pathology

Question 3

Commensal

Answer 3

an organism that is part of the normal flora

Question 4

Coagulase test

Answer 4

use to differentiate between Staph. aureus and coagulase negative Staph. (including Staph epidermis)

Question 5

Haemolysis test

Answer 5

used to differentiate between Streptococci

Question 6

Group A strep

Answer 6

Strep pyogenes

Question 7

Group B strep

Answer 7

Strep agalctiaea

Question 8

Group C/G strep

Answer 8

strep dysgalactiae

Question 9

Group D strep

Answer 9

strep bovis

Question 10

Gram Positive Cocci in chains

Answer 10

Staphylococcus aureus
Staphylococcus Epidermidis

Question 11

Disease presentation of staph aureus

Answer 11

Cellulitis, endocarditis, osteomyelitis, iatrogenic

Question 12

Disease presentation of staph epidermidis

Answer 12

endocarditis in prosthetic heart valves

Question 13

Virulence factors

Answer 13

Virulence factors result in disease caused by specific component of pathogen e.g. toxic shock

Question 14

TSST-1

Answer 14

superantigen which is the commonest cause of toxic shock

Question 15

Toxic Shock Syndrome diagnostic criteria

Answer 15

Fever (39℃)
Diffuse macular erythroderma and desquamation
Hypotension (≲90 mHg)
≳3 organ systems involved

Question 16

Panton-Valentine Leukocidin

Answer 16

Specific secreted proteins that form one functional complex that attacks white blood cells (specific toxicity for leukocytes)
Associated with severe skin infections e.g. recurrent furunulosis, sepsis/necrotising fasciitis

Question 17

Protein A

Answer 17

binds to Fc portion of antibodies, rendering them inaccessible to the opsonins, impairing phagocytosis

Question 18

Coagulase

Answer 18

protein enzyme tightly bound to the surface of S. aureus which can coat its surface with fibrin upon contact with blood → protects against phagocytosis

Question 19

Gram Positive Diplococci

Answer 19

Strep pneumoniae
Enterococcus faecium
Enterococcus Faecalis

Question 20

Disease presentation of strep pneumoniae

Answer 20

Pneumonia
Meningitis
Otitis media

Question 21

Disease presentation of enterococci

Answer 21

UTIs, and intra-abdominal infections

Question 22

Gram Positive Cocci in Chains

Answer 22

Strep pyogenes (Group A strep)
Strep agalactiae (Group B strep)

Question 23

Disease presentation of Group A strep

Answer 23

Tonsilitis
Scarlet fever
Rheumatic fever
cellulitis

Question 24

Disease presentation of Group B strep?

Answer 24

neonatal sepsis

Question 25

Gram Positive Bacilli?

Answer 25

Clostridium perfringens
Clostridium difficile
Clostridium tetani
Listeria monocytogenes

Question 26

Disease presentation of clostridium perfringens?

Answer 26

Gas gangrene
Cholecystitis
Gastroenteritis

Question 27

Disease presentation of listeria monocytogenes?

Answer 27

meningitis, gastroenteritis, neonatal sepsis

Question 28

Gram negative diplococci?

Answer 28

Neisseria meningitidis
Moraxella catarrhalis

Question 29

Gram negative coccobacilli

Answer 29

Haemophilus influenzae
Bordetella pertussis
Acinetobacter

Question 30

Gram negative bacilli?

Answer 30

E, coli,
proteus,
klebsiella

Question 31

Vibrios

Answer 31

vibrio cholerae

Question 32

Spirochetes

Answer 32

treponema pallidum (syphilis)
borrelia burgdorferi (lyme disease)

Question 33

Bacteria that don’t gram stain

Answer 33

Mycobacterium tuberculosis
Mycoplasma