Microbiology

Question 1

Most GI infections are related to?

Answer 1

• Cross-contamination of work surfaces/ utensils
• Undercooking
• Improper storage of food
• Poor reheating of food

Question 2

Most common cause of healthcare associated diarrhoea?

Answer 2

C. difficile infection

Question 3

C diff produces two toxins ____1_____ causes diarrhoea and ______2______ which produces infection

Generally patients present with ____________

Answer 3

1) enterotoxin (toxin A)
2) cytotoxin (toxin B)
3) diarrhoea (could be bloody), abdominal pain, pseudomembranous colitis or bowel perforation

Question 4

What is the only indication for oral vancomycin? Why?

Answer 4

Oral vancomycin is not absorbed systemically so the only indication to give it is C. diff infection

Question 5

Only way to wash hands when dealing with patients with C. diff or diarrhoea?

Answer 5

Soap and water as spores are resistant to alcohol wash

Question 6

What type of bacteria is C. diff?

Answer 6

Gram positive, spore producing, bacillus

Question 7

How do you test for C. diff?

Answer 7

It is not good at growing in culture. GDH test and then test for the toxins in patients with symptoms. Should note that the toxins stay in body for 12 weeks so can’t test to see if the patient is cured.

Question 8

Most common cause of diarrhoea in children under 3? How is it treated? Why is it uncommon now?

Answer 8

Rotavirus
It is self limiting so no treatment but babies may need fluid and electrolyte replacement
It is uncommon now as you can get a vaccine for it

Question 9

What is norovirus?

Answer 9

Winter vomiting disease

Question 10

What can cause oesophagitis?

Answer 10

Candida (usually in immune compromised)

Question 11

What can cause gastritis?

Answer 11

H. pylori

Question 12

3 important serotyping organisms in the gut?

Answer 12

• E. coli (O157)
• Salmonella
• Shigella

Question 13

Gram positive organism found in the mouth?

Answer 13

Strep Viridans

Question 14

Where do coliform mainly live?

Answer 14

In the colon

Question 15

What are two strict anaerobes? Where are they present in large numbers?

Answer 15

Clostridium and Bacteriodes

In the large bowel

Question 16

What are enterobacteriaceae? Examples?

Answer 16

Gram-negative bacteria of a large family that includes Escherichia coli, Klebsiella, Salmonella, Shigella.

Question 17

Describe enterococci? What is an important example?

Answer 17

Gram positive cocci

Enterococci faecalis can cause UTI and there are problems with drug resistance. It is in the large bowel.

Question 18

Most common source of campylobacter jejuni is ___1_____ It can also be caught from ____2______ particularly in _____3___ and in this case it will be treated with a ___4_____

It causes _________5__________

Answer 18

1) undercooked beef burgers or chicken
2) reptiles
3) immunosuppressed
4) macrolide
5) abrupt onset of nausea, diarrhoea and severe abdominal cramps

Question 19

Describe appearance of campylobacter

Answer 19

Bacteria has a corkscrew appearance with bipolar flagella

Question 20

Most common source of salmonella enteritis is _____1______ It can cause ___2_____ A common diagnostic technique is ______3________

Answer 20

1) poultry meat and raw egg
2) cramping, adobe pain, nausea, diarrhoea and fever
3) serotyping

Question 21

Listeria monocytogenes grows best at __1___ Often associated with ____2____ Can be a problem in ___3____

Answer 21

1) fridge temperatures around 5 degrees
2) deli counters and soft cheeses
3) pregnant women

Question 22

Appearance of listeria monocytogenes?

Answer 22

Gram positive rod

Question 23

Most cases of E.coli Gastroenteritis are caused by ____1______ This causes ____2_____ and the most common source is _________3_________ A serious complication is ____4_______ which is more likely to happen if you give ___5_____ to someone infected with this

Answer 23

1) E. coli 0157 (Shiga toxin producing)
2) bloody diarrhoea
3) beef, raw milk and animal contact
4) haemolytic uraemia syndrome
5) antibiotics

Question 24

4 important viruses in viral gastroenteritis?

Answer 24

Rotavirus, norovirus, adenovirus and astrovirus

Question 25

Enteric fever is most common in those returning from ___1____ It is spread by the ___2____ route

Typhoid is caused by ____3____
Paratyphoid which is less severe is caused by ____4__-

Answer 25

1) Indian subcontinent and SE Asia
2) faecal oral route
3) salmonella typhi
4) salmonella paratyphoid A, B or C

Question 26

Definition of traveller’s diarrhoea? Does this need treatment?

Answer 26

Passage of three or more unformed stools per day in a resident of an industrialised country travelling in a developing nation.

Usually self limiting, occasionally people take quinolone antibiotics

Question 27

Describe amoebae? Liver complication of amoebiasis?

Answer 27

Infection can cause diarrhoea and you get it from contaminated water it can go on to cause an amoebic liver abscess.

Question 28

Giardiasis is severe or not severe?

Answer 28

Not severe

Question 29

What antibiotic can both giardiasis and amoebae be treated with?

Answer 29

Metronidazole

Question 30

What protozoa disease causes oesophageal and colon problems?

Answer 30

Chagas disease

Question 31

In patients who have been to the tropics with raised eosinophils with no other reason what should you suspect?

Answer 31

Helminth infection

Question 32

What is the most common helminth infection in the world?

Answer 32

Ascariasis (round worm)

Question 33

What parasite from fresh water exposure can cause oesophageal varies without liver failure?

Answer 33

Schistosomiasis