Microbiology 3 - GI infections

Question 1

what is the most common cause of travellers diarrhoea?

Answer 1

E.coli (ETEC)

Question 2

3 different clinical syndromes of GI infections?

Answer 2

secretory diarrhoea, inflammatory diarrhoea and enteric fever

Question 3

Bloody diarrhoea associated with outbreaks

Answer 3

EHEC (Haemorrhagic E coli O157)

Question 4

most common cause of diarrhoea in <6? what type of diarrhoea?

Answer 4

Rotavirus

Secretory (due to toxin formation)

Question 5

Most common cause of diarrhoea in <2 years? what type of diarrhoea?

Answer 5

adenovirus

secretory diarrhoea

Question 6

what type of diarrhoea do viruses cause?

Answer 6

Secretory

Question 7

diarrhoea definition

Answer 7

loose or watery stools >/=3x/24 hours

Question 8

most common bloody travellers diarrhoea

Answer 8

Shigella

Question 9

which organisms are reportable

Answer 9

campylobacter
salmonella
shigella
E.coli o157
norovirus
listeria

Question 10

bacteria with incubation periods <6 hours?

Answer 10

S.aureus

bacillus cereus

Question 11

which infections have preformed toxins?

Answer 11

S.aureus
Bacilus cereus
Clostridium botulinum

Question 12

pathophysiology of secretory diarrhoea

Answer 12

toxin production –> Cl- secretion in to lumen –> loss of water and electrolytes –> D+V

NO FEVER, just WATERY diarrhoe
no WBCs in stool!

Question 13

features of inflammatory diarrhoea

Answer 13

FEVER
WBCs in stool sample (neutrophils)
+/- bloody diarrhoea

Question 14

enteric fever features

Answer 14

FEVER

WBCs in stool (mononuclear cells)

Question 15

examples of enteric fever causing organisms

Answer 15

salmonella typhi –> typhoid fever
yersinia
brucella

Question 16

some causes of persistent or chronic diarrhoea

Answer 16

Cryptosporidium spp., Giardia lamblia, entamoeba histolytic, cyclospora

Question 17

N+V <24 hours

Answer 17

S.aureus

B.cereus

Question 18

vomiting and NON-BLOODY diarrhoea 2-3DAYS

Answer 18

NOROVIRUS

Question 19

Features of S.aureus food poisoning

Answer 19

coagulase, catalase +Ve gram+ve coccus

Question 20

superantigen in S.aureus

Answer 20

produces and entero and exotoxin which act as super antigen and cause release of IL-1 + 2 –> watery, NON bloody diarrhoea

Question 21

examples of gram positive spore forming rods

Answer 21

Bacilus cereus
Listeria
clostridia

Question 22

reheated fried rice, vomiting 4 hours after eating

Answer 22

b-cereus

Question 23

three types of clostridium infection

Answer 23

c. botulinum
c. perfringens
c. difficile

Question 24

descending paralysis with canned foods/honey

Answer 24

c.botulinum, treat with anti toxin

Question 25

8-16 hours after eating reheated meat, watery diarrhoea, vomiting lasting 24 hours, gas gangrene

Answer 25

C.perfringens

Question 26

3 C's of c.difficile

Answer 26

cephalosporins, clindamycin and cirpfloxacin

Question 27

pseudomembranous colitis

Answer 27

c.difficile

Question 28

refrigerated food/ cold enhancement/ gram positive rod

Answer 28

listeria monocytogenes

Question 29

which E coli --> HUS?

Answer 29

EHEC, O157

Question 30

which part does E.coli act on?

Answer 30

Jejunum or ileum, NOT the colon

Question 31

EPEC; pathogenic --> ?

Answer 31

Infantile diarrhoea

Question 32

EIEC -->

Answer 32

Invasive, dysentery

Question 33

what should be avoided in the E.coli infections?

Answer 33

ANTIBIOTICS

Question 34

WHICH Subspecies of salmonella --> enterocolitis?

Answer 34

S.enteritidis

Question 35

6 clinical features of salmonella typhi infection?

Answer 35

``` Transmitted by humans Multiplies in Peyers' patches Bacteraemia (SCD) Slow onset, fever and CONSTIPATION SPLENOMEGALY ROSE SPOTS ```

Question 36

Treatment of S.typhi

Answer 36

Ceftriaxone

Question 37

Salmonella H2S producer? (HYDROGEN SULFIDE)

Answer 37

YES

Question 38

Shigella H2S producer?

Answer 38

NO

Question 39

MSM GI infection

Answer 39

sHIGELLA (S.FLEXNERI)

Question 40

Which GI infection is associated w necrotising granulomas and reactive arthritis?

Answer 40

Yersinia enterocolitis

Question 41

Name 2 GI infections which prefer 4C?

Answer 41

Listeria + Yersinia

Question 42

curved, comma shaped, rice water stools

Answer 42

Vibrio choelra

Question 43

curve, comma shaped, GBS

Answer 43

Campylobacter jejuni

Question 44

treatment of cholera

Answer 44

treat the losses

Question 45

treatment of C.jejuni

Answer 45

only tx if immunocompromised or if first 4-5 days of illness - macrolide

Question 46

symptoms of campylobacter jejuni

Answer 46

watery, foul smelling diarrhoea, bloody stool, fever and severe abdominal pain

Question 47

protozoa causing diarrhoea

Answer 47

Giardia lamblia Entamoeba histolytica Cryptosporidium parvum

Question 48

trophozoite, pear shaped with 2 nuclei

Answer 48

Giardia lamblia

Question 49

presentation of giardiasis?

Answer 49

foul smelling nON-BLOODY diarrhoea (fat and protein malabsorption)

Question 50

treatment of gardia

Answer 50

Metro

Question 51

entamoeba motile trophozoite --> ?

Answer 51

Diarrhoeal illness

Question 52

entamoeba non motile cyst --> ?

Answer 52

non-diarrhoea illness

Question 53

symptoms of diarrhoea entamoeba

Answer 53

dystentery, flatulence, tenesmus, LIVER ABSCESS

Question 54

Protozoa with 4 nuclei --> dysentery

Answer 54

ENTAMOEBA

Question 55

Treatment of entamoeba

Answer 55

Metronidozale + paromomycin

Question 56

cause of severe diarrhoea in immunocompromised? What is seen in the stool?

Answer 56

Cryptosporidium parvum Oocytes

Question 57

rotavirus - what is required for lifelong immunity?

Answer 57

exposure to natural infection twice

Question 58

viral causes of diarrhoe

Answer 58

norovirus, rotavirus, adenovirus

Question 59

immunity in norovirus

Answer 59

NO LONG TERM IMMUNITY