Microbiology Flashcards
Most GI infections are related to?
- Cross-contamination of work surfaces/ utensils
- Undercooking
- Improper storage of food
- Poor reheating of food
Most common cause of healthcare associated diarrhoea?
C. difficile infection
C diff produces two toxins ____1_____ causes diarrhoea and ______2______ which produces infection
Generally patients present with ____________
1) enterotoxin (toxin A)
2) cytotoxin (toxin B)
3) diarrhoea (could be bloody), abdominal pain, pseudomembranous colitis or bowel perforation
What is the only indication for oral vancomycin? Why?
Oral vancomycin is not absorbed systemically so the only indication to give it is C. diff infection
Only way to wash hands when dealing with patients with C. diff or diarrhoea?
Soap and water as spores are resistant to alcohol wash
What type of bacteria is C. diff?
Gram positive, spore producing, bacillus
How do you test for C. diff?
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.
Most common cause of diarrhoea in children under 3? How is it treated? Why is it uncommon now?
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
What is norovirus?
Winter vomiting disease
What can cause oesophagitis?
Candida (usually in immune compromised)
What can cause gastritis?
H. pylori
3 important serotyping organisms in the gut?
- E. coli (O157)
- Salmonella
- Shigella
Gram positive organism found in the mouth?
Strep Viridans
Where do coliform mainly live?
In the colon
What are two strict anaerobes? Where are they present in large numbers?
Clostridium and Bacteriodes
In the large bowel
What are enterobacteriaceae? Examples?
Gram-negative bacteria of a large family that includes Escherichia coli, Klebsiella, Salmonella, Shigella.
Describe enterococci? What is an important example?
Gram positive cocci
Enterococci faecalis can cause UTI and there are problems with drug resistance. It is in the large bowel.
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__________
1) undercooked beef burgers or chicken
2) reptiles
3) immunosuppressed
4) macrolide
5) abrupt onset of nausea, diarrhoea and severe abdominal cramps
Describe appearance of campylobacter
Bacteria has a corkscrew appearance with bipolar flagella
Most common source of salmonella enteritis is _____1______ It can cause ___2_____ A common diagnostic technique is ______3________
1) poultry meat and raw egg
2) cramping, adobe pain, nausea, diarrhoea and fever
3) serotyping
Listeria monocytogenes grows best at __1___ Often associated with ____2____ Can be a problem in ___3____
1) fridge temperatures around 5 degrees
2) deli counters and soft cheeses
3) pregnant women
Appearance of listeria monocytogenes?
Gram positive rod
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
1) E. coli 0157 (Shiga toxin producing)
2) bloody diarrhoea
3) beef, raw milk and animal contact
4) haemolytic uraemia syndrome
5) antibiotics
4 important viruses in viral gastroenteritis?
Rotavirus, norovirus, adenovirus and astrovirus
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__-
1) Indian subcontinent and SE Asia
2) faecal oral route
3) salmonella typhi
4) salmonella paratyphoid A, B or C
Definition of traveller’s diarrhoea? Does this need treatment?
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
Describe amoebae? Liver complication of amoebiasis?
Infection can cause diarrhoea and you get it from contaminated water it can go on to cause an amoebic liver abscess.
Giardiasis is severe or not severe?
Not severe
What antibiotic can both giardiasis and amoebae be treated with?
Metronidazole
What protozoa disease causes oesophageal and colon problems?
Chagas disease
In patients who have been to the tropics with raised eosinophils with no other reason what should you suspect?
Helminth infection
What is the most common helminth infection in the world?
Ascariasis (round worm)
What parasite from fresh water exposure can cause oesophageal varies without liver failure?
Schistosomiasis
