Bacteria of GI

Question 1

pathogens

Answer 1

microorganism that has potential to cause disease

Question 2

virulence

Answer 2

likelihood of causing disease

Question 3

accidental pathogen

Answer 3

pathogen only problematic in people with low immune systems

Question 4

5 signs of inflammation

Answer 4

calor, rubor, tumor, dolor, function

Question 5

Common microbiology investigations

Answer 5

• stool, urine
• sputum, pus
• serology
• antigen detection
• PCR

Question 6

What are the risk factors for GI illness

Answer 6

• **unpasteurised food
• raw/ undercooked food
• contaminated water
• childcare/ healthcare
• animal/ contact of animal excretion

Question 7

Campylobacter:
- shape
- commonly causes what?
- What are the symptoms?
- how is it transmitted?
-** what are its main risk factors?**
- what are its complications?

Answer 7

• spiral
• diarrhoea + dysentery (bloody diarrhoea)
• diarrhoea and cramps
• transmitted via faecal oral, but sometime person to person
• undercooked poultry, contaminated water, unpasteurised milk, bird, warm temp, travelliing, H2 blockers, PPi
• guillan-barre, reactive arthritis, irritable bowel

Question 8

Salmonella
- is this gram positive or negative + what shape?
- how is salmonella transmitted
- what are the risk factors
- what can it cause in immunosuppressed pts?
- specifically, what kind of immunosuppressed pts?
- what is the main salmonella species?

Answer 8

• gram negative + rod
• foodborne
• RF: travel, eggs, pet food, reptiles, reduced stomach acid (due to PPI, in infants)
• endocarditis, aortitis, visceral infections, meningitis
• pts with haemoglobinopathies, HIV, pts on chemo, low stomach acid
• enterica

Question 9

In labs, what antigen variation can be used to identify serotypes?

Answer 9

lipopolysaccharides (o antigen)
flagellar antigen (H antigen)
capsular polysaccharide (Vi antigen) - diagnostic marker for identifying Salmonella Typhi strains

Question 10

What is bacillary desentery caused by?

Answer 10

shigella and E coli

Question 11

could be in exams

main risk factor of E Coli 0157

Answer 11

petting zoo, undercooked meat

Question 12

Listeria:
- shape
- prefers hot or cold environ?
- commonly causes what?
- what are its main risk factors?

Answer 12

• gram positive rods
• cold
• meningitis or bacteraemia and diarrrhoea
• ## pregnancy and immnocompromised, unpasteurised milk, dairy products

Question 13

Other bacterial diarrhoea includes: Yersinia enterocolitica, Vibrio cholerae, aeromonas, bacillus cereus - where are these found?

Answer 13

YE - associated with pigs
VC - electrolyte issues and water diarrhoea
A - water related (immmuncompromised RF)
BC - reheated food

Question 14

Infections of abdomen

Answer 14

• peritonitis (primary + secondary)
• liver abscess
• cholangitis
• abscesses/ perineal abscesses

Question 15

name 4 gram negative and 3 gram positive organisms (main for GI)

Answer 15

Negative: E coli, kliebsiella spp., pseudomonas, enterobacter
Positive: Enterococcus, streptococcus, staph

Question 16

Main antibiotics used for gram negatives?

Answer 16

beta lactams + aminoglycosides + co-trimoxazole
- macrolides, tetracyclines

Question 17

Antibiotics to treat coliforms?

Answer 17

gentamicin

Question 18

Antibiotics to treat anaerobes?

Answer 18

metronidazole

Only acts against anaerobes

Question 19

Antibiotics to treat enterococcus

Answer 19

amoxicillin

Question 20

What is the treatment for intra-abdominal sepsis? What is pt is penicillin allergic?

Answer 20

Gentamicin, amoxicillin + metronidazole
- co-trimoxazole, gentamicin, metronidazole

Question 21

What is the positive result for enterobacteria on MacConkey Agar?

Answer 21

lactose fermentors turn pink

Question 22

If patient is immunocompromised, elderly or has prolonged symptoms with campylobacter, what antibiotic wld u give?

Answer 22

clarithromycin

Question 23

Norovirus:
- temperature it survives in?
- mode of transmission?
- Hand washing or alcohol gel effective?
- how long are you infectious for?
- what investigations?

Answer 23

• cold + heat
• direct contact, food/ drink, environment, aerosol
• hand washing
• 48 hours
• stool samples

Question 24

Rotavirus:
- who does this affect?
- when is the vaccine given?
- who are at risk?
- how is it transmitted?

Answer 24

• children
• orally < 15 months of age
• immunosuppressed and age < 65
• faecal oral/ resp

Question 25

EBV infects B lymphocytes
- how is transmitted
- what are the symptoms

Answer 25

• saliva and body fluids
• fever, sore throat, lymphadepnopathy, hepatitis, rash, splenomegaly, fatigue

Question 26

• symptoms of acute cytomegalovirus infection
• symptoms in immunocompromised?
• diagnostic method

Answer 26

• fever, fatigue, sore throat, swollen lymph nodes
• colitis, bloody diarrhoea
• biopsy

Question 27

Cryptosporidium
- how does it present in immunosuppressed
- how is it acquired

Answer 27

• chronic diarrhoea, nutritional deficiencies, weight loss, dehydration
• contaminated oocytes ingested in water or infected soil/ crops

Question 28

Giardia Lamblia
- where is it found, how is it transmitted and what are the symptoms?
- treatment

Answer 28

• flagellated protozoa
• found in swimming pools or lakes in untreated water
• transmitted person to person
• symptoms: foul smelling diarrhoea, explosive intermittent burps
• can lead to chronic malabsorptive diarrhoea
• metronidazole

Question 29

Symptoms of Entamoeba Histolytica

Answer 29

bloody diarrhoea, weight loss, pain