Infectious Diseases GI Flashcards Preview

GastroIntestinal (GI) > Infectious Diseases GI > Flashcards

Flashcards in Infectious Diseases GI Deck (68):
1

What immune system eliminates most of the intestinal infection?

The Innate Immune System

2

What is the mechanism of the innate immune system?

Mucus
IgA coating
Membrane attack complex
Activation through ligation of pattern recognition receptors (Toll-like receptors)
Intracellular receptors signal via NFkB pathway

3

What does signalling via the NFkB system do to the cell?

It causes t he cell it become activated.
Secretion of Chemokines, defensins, cytokines

4

What determines the outcome of the infection?

Immune genetics.
Too strong an immune response will cause damage to the body. e.g. crohn's or ulcerative colitis
Too little an immune response and the pathogen will not be removed

5

What is diarrhoea?

Unformed stools
No other cause
Stool holds shape on container

6

How can you assess the stool?

Bristol stool chart

7

What is food poisoning?

Illness cases by eating contained food - with micoorganisms.

8

What organisms cause food poisoning?

Campylobacter - most common food poisoning
Salmonella - In immunosuppressed patients (second most common)
E coli

9

What is the incubation time of staph aureus/ bacillus cereus

1-6 hours

10

What is the incubation time for salmonella?

12-48 hours

11

What is the incubation time of campylobacter?

2-14 days
Does not spread person to person easily

12

How is campylobacter treated?

Ciprofloxacin/erythromcin

13

What is the most common form of salmonella?

Salmonella enteritidis

14

How is salmonella treated?

Ciprofloxacin

15

How is salmonella typed?

antigen typing
- anti-body produces that detects specific antigen. The body of lamella has the O antigen, and the tail has the H antigen.
Antigen agglutinates with the corresponding antibody

16

What is the sign for e coli ?

Bloody diarrhoea
- there is person to person and direct/indirect contamination

17

What toxin does e coli 0157 produce?

Verotoxin

18

What are signs of coli 0157?

Bloody diarrhoea
Haemorrhagic colitis

19

What syndrome can coli 0157 cause?

Haemolytic uraemic sydnrome
- caused by Verotoxin. Appears when the diarrhoea is clearing

20

What does Verotoxin do?

Binds to receptors on renal cells and red blood cells.
This inhibits protein synthesis - causes cell death

21

How can HUS be detected?

Fever
Abdo pain
Pallor
Petechiae
Oliguria
Blood diarrhoea
Acute renal failure
Thrombocytopaenia
Haemolytic anaemia

22

What tests are done for HUS?

U and E
FBC
LFT
Clotting
Urine
Lactate

23

What is the management of HUS?

No antibiotics
No anti-motility agents
No ASAIDS

24

How is Ecoli 0157 diagnosed?

Selective culture - use of sortbitol sugar, which Ecoli 0157 doesn't use. (The selective culture should turn from organ to pink, if it doesn't - it is 0157 )
Detection of Verotoxin

25

What is an antibiotic?

A substance that kills or inhibits the growth of a mircoorganism

26

What is susceptible mean?

arbitrary designation that implies that an antimicrobial will inhibit bacterial growth at clinically achievable concentrations

27

What does MDR bacteria mean?

non-susceptibility to at least 1 agent in 3 or more antimicrobial categories

28

What does XDR bacteria mean?

non-susceptibility to at least 1 agent in all but 2 or fewer antimicrobial categories (ie, bacterial isolates remain susceptible to only 1 or 2 categories)

29

What does PDR bacteria mean?

non-susceptibility to all agents in all antimicrobial categories (ie, no agents tested as susceptible for that organism)

30

How do beta-lactams work?

Attack the protein wall by acting on the penicillin binding proteins - this will break up the cell wall

31

What are the beta lactase?

Penicillins: amoxil, coamoxiclav, piperacilli-tazpbactam

32

How does ciprafloxacin work?

Works on the DNA

33

What drives antimicrobial resistance?

May have resistance already
Bacteria can transfer DNA via plasmid transfer

34

What are the methods of microbial resistance?

Altering the target site of the antibiotic
Preventing access to the target site
Inactivating the antibiotic

35

What are the multi-drugs resistant bacteria?

Enterococcus faecium
Staphylococcus aureus
Clostridium difficile
Acinetobacter baumannii
Pseudomonas aeruginosa
Enterobacteriaceae

36

What is the increased risk of resistance once your prescribe something and it comes back?

2 fold increase of resistance.

37

what are the basic principals of treating a pathogen?

Define the pathogen
Treat the patient - not the culture
Match aggressive Rx to severity
Find the source e.g. drains, pus. (always remove pus)

38

What type of antibiotic will cause resistance?

Broad spectrum antibiotic
Antibiotics given for too long
Low doses of antibiotics

39

What is acute traveller's diarrhoea?

3 loose stools in 24 hours
Associated with fever

40

What causes Acute traveller's diarrhoea generally?

E coli

41

What pathogen is associated with bloody diarrhoea / dysentery?

E coli

42

What pathogen is associated with profuse watery diarrhoea?

Cholera

43

What test is done for acute traveller's diarrhoea?

Stool Culture

44

What is the treatment for acute traveller's diarrhoea?

Fluroquinolone is helpful
If not it will resolve itself

45

What bacteria causes Typhoid?

Salmonella Typhi

46

What are the investigations that should be carried out for jaundice and fever, after traveling?

Malaria blood film and rapid antigen
Blood film for red cell fragmentation
FBC/UE/LFT/coagulation
Blood cultures
USS abdomen
Serological testing for viruses

47

What pathogens may cause jaundice and fever?

Malaria
Sickle cell crisis
Hepatitis A
Hepatitis E
Typhus

48

What are the symptoms for inta-abdominal infection?

Pain
Tenderness
Constipation or diarrhoea
Fever
Rigors
Nausea

49

What is SIRS ?

Systemic Inflammatory Response Syndrome.
A non-sepcific clinical response:
Temperature >38
Pulse > 90
Respiratory >20
White cell count > 12000

(Not all SIRS is related to Infection)

50

What is Sepsis?

Systemic Inflammatory response + Suspected Infection

51

What is the disease continuum of sepsis?

Infection
Sepsis
Sever sepsis
Septic shock

52

How do you investigate sepsis?

Blood culture
Full Blood count
Lactate
Urine Output

53

How do you treat sepsis?

Fluids
Antibiotics
Oxygen

54

What test helps tests for past diseases?

Serological testing

55

What is Bacteraemia?

Blood stream infection

56

What are the community acquired infections that cause Bacteraemia?

E-coli
Staph aureus
Streptoccus pygoenes

57

What are the hospital acquired infections that cause bacteraemia?

E coli
Staph aureus
Coagulase negative
Enterococcus
Psuedomonas (typically in oncological malignancy)
Candida

58

What type of bacteria is Pseudomonas?

Gram Negative
Strict Aerobe

59

What bacteria generally affect the mouth?

Strep. “viridans”, Neisseria sp., anaerobes
Candida sp. (few), Staphylococci

60

What bacteria generally affect the stomach/duodenum?

Few Candida sp. & Staphylococci may survive
Helicobacteria Pylori for peptic ulcers

61

What bacteria generally affect the jejunum?

Small numbers of coliforms and anaerobes

62

What bacteria generally affect the colon?

Large numbers of coliforms anaerobes and Enterococcus faecalis

63

What antibiotic is used for gram positive bacteria?

Amoxicillin
e.g. for steptococci and enterococci

64

What antibiotic is used for coliforms?

Gentamicin

65

What antibiotic is used for anaerobes and bactericides?

Metronidazole

66

What are the side effects of gentamicin?

Kidney and hearing problems

Treatment is typically only 72 hours to prevent problems

67

What is septic shock?

Severe sepsis with hypotension even with adequate administer fluids or requiring vasopressors or inotropes

68

What can intra-adbominal infection be caused by?

Peritonitis.
Perforation:
Perforated duodenal ulcer
Perforated appendix
Perforated diverticulum
Perforated tumour