MRSA

Question 1

Screen

Answer 1

How should a patient be screened for MRSA?
nasal swab and skin lesions or wounds
the swab should be wiped around the inside rim of a patient’s nose for 5 seconds
the microbiology form must be labelled ‘MRSA screen’

Question 2

Treatment

Answer 2

vancomycin
teicoplanin
linezolid

Question 3

C Diff Features

Answer 3

Clostridioides difficile is a Gram positive rod often encountered in hospital practice. It produces an exotoxin which causes intestinal damage leading to a syndrome called pseudomembranous colitis. C. difficile develops when the normal gut flora are suppressed by broad-spectrum antibiotics. Clindamycin is historically associated with causing C. difficile but the aetiology has evolved significantly over the past 10 years. Second and third-generation cephalosporins are now the leading cause of C. difficile.

Other than antibiotics, risk factors include:
proton pump inhibitors

Pathophysiology
anaerobic gram-positive, spore-forming, toxin-producing bacillus
transmission: via the faecal-oral route by ingestion of spores
releases two exotoxins (toxin A and toxin B) that act on intestinal epithelial cells and inflammatory cells resulting in colitis

Question 4

C Diff Present

Answer 4

diarrhoea
abdominal pain
a raised white blood cell count (WCC) is characteristic
if severe toxic megacolon may develop

Question 5

C Diff Diagnosis

Answer 5

is made by detecting C. difficile toxin (CDT) in the stool
C. difficile antigen positivity only shows exposure to the bacteria, rather than current infection

Question 6

C Diff Treatment

Answer 6

Current antibiotic therapy should be reviewed and antibiotics stopped if possible.

First episode of C. difficile infection
first-line therapy is oral vancomycin for 10 days
second-line therapy: oral fidaxomicin
third-line therapy: oral vancomycin +/- IV metronidazole

Recurrent episode
recurrent infection occurs in around 20% of patients, increasing to 50% after their second episode
within 12 weeks of symptom resolution: oral fidaxomicin
after 12 weeks of symptom resolution: oral vancomycin OR fidaxomicin

Life-threatening C. difficile infection
oral vancomycin AND IV metronidazole
specialist advice - surgery may be considered

Other therapies
bezlotoxumab is a monoclonal antibody which targets C. difficile toxin B
NICE do not currently support its use to prevent recurrences as it is not cost-effective
faecal microbiota transplant
may be considered for patients who’ve had 2 or more previous episodes