GI tract infections

HideShow resource information
  • Created by: Amh
  • Created on: 08-04-16 17:39
What are gut defence mechanisms
Acidic pH in stomach, phagocytosis, and IgA in the gut, peristalis of the gut, and normal microflora
1 of 47
When are gut defecnces comprimised
Age illness drugs
2 of 47
What are the clinical features of GI infections
Diarrhoa maybe dysrentery, nausea, comitting, abdominal pain, fever headache
3 of 47
What type of campylobacter commonly cause GI infections
C jejuni C coli
4 of 47
whee do get campylobacter infections from
eating undercooked poultry
5 of 47
What is the clinical manifestation of a campylobacter infection
Causes bloody diarrhoea with fever and abdominal pain 2 – 5 days after ingestion
6 of 47
What is the appearance of campylobacter
gram negatice rod seagull
7 of 47
Is campylobacter fastidious
yes requires charcole cefoperazone, desoxycholate, amphotericin agar and microaerophillic incubation at 42 degreees cent
8 of 47
What species of salmonella cause GI infection
S enteritidis S typhi S paratyphi
9 of 47
outline typhoid fever
Incubation period 2 weeks, Septicaemia, high fever, constipation rather than diarrhoea – ‘Rose spots’ on skin - rash
10 of 47
How do you diagnose Salmonells
First use selenite broth then culture onto XLD
11 of 47
How salmonella appear on XLD
red colonies black centres because they produce H2S
12 of 47
Does salmonella ferment lactose
No
13 of 47
What serologies do you do to confirm salmonella
Poly ‘O’ and ‘H’ antisera • Specific antsera for O and H types • Kauffmann – White Scheme
14 of 47
What are some key shigella species
S. sonnei, dysenteriae, flexneri, boydii
15 of 47
why does shigella spread so easily
there is a very small infective dose
16 of 47
How does shigella appear on XLD
Red no black dots
17 of 47
What are the characteristics of clostridia perfringens
Anaerobic gram positive rods sporulate and release enterotoxins
18 of 47
What are the symptoms of clostridia perfringens infections
Watery diarrhoea – Abdominal cramps – Vomiting – Fever.
19 of 47
How do we demonstrate presence of toxin
Nagler plate
20 of 47
Is Clostridium difficile part of our normal flroa?
yes
21 of 47
When does C difficile become an issue
when antibiotics deplete the other flora and produces toxins A and B
22 of 47
What are the severe complications of C fifficile colitis
– progressing to pseudomembranous colitis – Toxic megacolon Colonic perforation, acute abdomen, sepsis, death
23 of 47
What is Bacilus cereus also known as
Chinese Restaurant Syndrome
24 of 47
what is the disease caused by
cells vegetating and releasing toxins, we ingest toxins
25 of 47
What are the symtoms of this disease
Severe vomiting 1 – 5 hrs later (emetic toxin) • Followed by diarrhoea 8 – 16 hrs later (diarrhoeal toxin)
26 of 47
What are the characteristics of B cereus
is grows aerobically as blue colonies on B. cereus agar
27 of 47
What is another toxin mediated disease
S aureus
28 of 47
How long does it take to see symptoms from S aureus
1-6 hours
29 of 47
How do you diagnose S aureus GI infection
clinically can use PCR for enterotoxin
30 of 47
What forms of e coli can cause diseases
Enteropathogenic E. coli (EPEC) – Enterotoxigenic E. coli (ETEC) • Travellers diarrhoea – Enteroinvasive E. coli (EIEC) – Enteroaggregative E. coli (EAEC) – Diffusely adherent E. coli (DAEC) • Verotoxigenic E. coli (VTEC)
31 of 47
What does verotoxigenic ecolicause
Shiga like toxin, Haemolytic uraemic syndrome
32 of 47
What does Haemolytic uraemic syndrome lead to
haemorrhagic colitis, acute renal failure, thromobocytopenia
33 of 47
What is E coli asscoiated with
undercooked beef burgers
34 of 47
What is the commonest strain of VTEC
0157
35 of 47
Does 0157 ferment sorbitol
no
36 of 47
Which comma shaped gram negative bacteria is another toxin mediated disease
Vibrio species
37 of 47
What are 2 types of vibrio that cause disease
V. Cholerae • V. parahaemolyticus
38 of 47
Where are you most likely to get V. parahaemolyticus from
Shellfish
39 of 47
How do you culture and identify vibrio
on TCBS media (yellow colonies) gram negative
40 of 47
How does the cholera toxin cause disease
it deregulates cell membrane causing an elecktrolye efflux
41 of 47
Why is it hard to culture and identify pathogen microorgansims
Because we use stool samples which have a great deal of normal flora, shigell and salmonella are both eneterobacteriaceae, and many need different enrichment and media
42 of 47
What is a common cause of viral gastroenteritis
NoRovirus
43 of 47
Are viral GI infections serious
not usually
44 of 47
What is the treatment for gi infections
rehydration, maintain electrolytes, Ciprofloxacin / erythromycin
45 of 47
How do you trea C dif
stop antibiotics, faecal transplant / Metronidazole / vancomycin
46 of 47
Can you vaccinate against gi infections
yes against ETEC and rotavirus
47 of 47

Other cards in this set

Card 2

Front

When are gut defecnces comprimised

Back

Age illness drugs

Card 3

Front

What are the clinical features of GI infections

Back

Preview of the front of card 3

Card 4

Front

What type of campylobacter commonly cause GI infections

Back

Preview of the front of card 4

Card 5

Front

whee do get campylobacter infections from

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all micro resources »