Antibiotic Awareness Week (18th-24th November) is part of a global initiative to raise awareness of antibiotic resistance and promote the responsible use of antibiotics: ‘No action today, no cure tomorrow’.

Each day this week we will be bringing you an Antibiotic Awareness Message of the Day.

Today’s message: Obtain cultures before starting therapy

Quiz question 1.

Which of the following samples are useful to send to the microbiology lab?

A.      A swab of pus

B.      A slide of pus

C.      A bucket of pus

D.      A blood culture taken before antibiotics

E.      A blood culture taken after antibiotics

F.      Fresh tissue

G.      Tissue in saline

H.      Tissue in formalin

*           Always collect specimens to confirm infection, preferably before antibiotics are commenced, as antibiotics decrease the yield of culture significantly. Blood, urine, nose/throat and wound swabs and tissue specimens may verify your clinical diagnosis and provide antibiotic susceptibility results to target specific organisms.

*           Identifying a viral aetiology may reduce the need for antibiotics. Viral infections do not require antibiotics unless a secondary bacterial infection is suspected.

*           Drain pus collections to hasten recovery and send the pus to the Microbiology Laboratory for culture.

*           Don’t put tissue specimens for bacterial culture in formalin (yes, it happens frequently).

*           Further information is available from the Pathology Specimen Collection resource: http://ww2.rch.org.au/specimen/

Answer: All except H.

A.      A swab of pus – yes, but if you have more, send more

B.      A slide of pus – yes always, as it allows a Gram stain which can help identification

C.      A bucket of pus – yes yes yes

D.      A blood culture before antibiotics – the ideal situation

E.      A blood culture after antibiotics – still worth sending as organisms may be persistent or resistant

F.      Fresh tissue – the ideal sample

G.      Tissue in saline – only if the sample is very small and might dry out

H.      Tissue in formalin – no, never!

On behalf of the RCH Antimicrobial Stewardship Committee (Penelope Bryant (chair), Andrew Daley, Nigel Curtis, Antun Bogovic, Mike South, Mike Starr, Sharon Smith, Jonathan Burge) http://www.nps.org.au/about-us/what-we-do/campaigns-events/antibiotic-resistance-fighter