bacterial properties and disease

Question 1

3 potential sources of bacteria

Answer 1

intrinsic (from inside you), extrinsic (from outside you), mythical (e.g. getting a cold from being in the cold)

Question 2

sites of intrinsic bacteria

Answer 2

nasal cavity and sinuses, upper respiratory tract, stomach, appendix, skin, lower genital tract, large and small intestines, mouth

Question 3

define expected extrinsic

Answer 3

normal (harmless) microbiota enter via expected route

Question 4

define unexpected extrinsic

Answer 4

normal bacteria enter unusual site or pathogenic microbiota entering anywhere

Question 5

4 portals of entry

Answer 5

upper respiratory tract, urogenital tract, broken skin, GIT

Question 6

upper respiratory tract: how is bacteria acquired

Answer 6

extrinsically as droplets or airborne, with hand transmission as an intermediate

Question 7

upper respiratory tract: example bacteria

Answer 7

S. aureus, S. pneumoniae

Question 8

upper respiratory tract: infections

Answer 8

tonsillitis, sinusitis

Question 9

upper respiratory tract: where can it spread (3 places)

Answer 9

adjacent tissues (middle ear infection, brain abscess, meningitis), lower respiratory tract (bronchitis, pneumonia, empyema), bloodstream (bacteraemia)

Question 10

urogenital tract: intrinsic sources

Answer 10

bacteria from large intestine (anus close so bladder infections)

Question 11

urogenital tract: intrinsic bacteria

Answer 11

S. grp B, candida

Question 12

urogenital tract: extrinsic sources

Answer 12

catheter infections

Question 13

urogenital tract: extrinsic bacteria

Answer 13

STI: chlamydia, gonorrhoeae

Question 14

broken skin: causes

Answer 14

surgery, any wound, skin diseases (e.g. eczema, pressure sores), IVDA, insect bites

Question 15

broken skin: examples of skin and mouth bacteria

Answer 15

S. aureus, S. pyogenes

Question 16

broken skin: bacteria outcome if on antibiotics

Answer 16

can become more resistant - MRSA, pseudomonas

Question 17

broken skin: bacteria after surgery (e.g. bowel)

Answer 17

S. aureus, S. pyogenes, MRSA, pseudomonas, gram -ve bacteria from gut

Question 18

GIT: causes

Answer 18

contaminated food, water

Question 19

GIT: bacteria examples

Answer 19

E. coli, Shigella, V. cholerae, Salmonella

Question 20

GIT: diarrhoeal

Answer 20

vomiting only (toxins), diarrohoea only, bloody diarrhoea (typhoid - more invasive)

Question 21

GIT: bacterermic/systemic infection

Answer 21

bacteria spread to bloodstream e.g. typhoid

Question 22

GIT: toxin-mediated

Answer 22

if only toxin ingested - diarrhoea, vomitting and neurological e.g. botulism