STANDARD OPERATING PROCEDURES FOR PUS CULTURE

1. SPECIMEN:

1. Pus Swab

2. CULTURE MEDIA:

1. MacConkey Agar (MA)
2. Blood Agar (BA)
3. Thio Glycolate Broth (TGB)

3. PROCEDURE:

1. If 2 swabs are received - one is cultured on Blood Agar (BA) and MacConkey Agar (MA) by applying the swab on the primary inoculation site on BA and MA and then streaked to get isolated colonies.
   1. One swab is inoculated in TGB medium.
   2. The other swab is used for preparing the direct smear.
2. If only 1 smear is received it should be first cultured and then processed for smear.
3. If pus discharge/aspirate is sent
   1. 1 loopful is used to inoculate BA and MA and one loopful is put in TGB
   2. 1 loopful is used for direct smear
4. After 24 hours, observe the culture:
   1. If growth occurs proceed for identification
      1. Identify and do Antibiotic sensitivity if 1 or 2 organism are grown.
      2. 3 or more types are reported as such and no complete identification and antibiotic sensitivity reported. An indication of predominant bacteria growing out of the 3 types may be given.
      3. In case of diphtheroids - report as possible contaminants.
      4. Coagulase negative staphylococcus from catheter may be significant. Other sites may be reported as possible contaminants.
   2. If the culture is sterile after 24 hours examine the Thio glycolate broth (TGB)
      1. If Turbid - Subculture into BA and MA (may not give a true picture in case of catheters where quantitative assessment is done)