✨MEDIA
An artificial food for the cultivation of microorganisms in laboratory.
★ Types :
- On the Basis of Consistency:
–Solid media (Nutrient agar , Blood agar, Chocolate agar)
–Semisolid media (Soft Agar Media)
–Liquid media (Peptone water, Bile broth, Sugar broth)
- On the basis of oxygen requirement :
-Aerobic
-Anaerobic
- On the basis of Chemical Composition :
✨Simple media
✨Special media :
- Enriched media– Blood agar medium.
- Enrichment medium – Tryptic soya broth.
- Selective media– Mac Conkey’s agar , Blood tellurite agar.
- Indicator media -Blood agar.
- Transport media – Stuart media.
- Storage media – Egg saline medium.
★ Today we will discuss about Blood Enriched media’s :
Blood Agar :
Media Identifying point :
- Red colour , Solid enriched Media
Composition :
- Nutrient Agar + 5-10% Sheep Blood
Indication of Blood Culture :
- Enteric fever
- Septicaemia
- Bacteremia
- Meningitis
- Pyrexia Of Unknown Origin
- Bacterial infective endocarditis
- Osteomyelitis
- Brucellosis
★ How do you Enrich blood culture media?
- Tryptic soy broth.
- Diphasic tryptone soya media.
- Bile salt with or without gentian violet
- Thioglycolate broth for growth of anaerobes
- Brain heart infusion broth
★ What is the purpose of Enrichment?
-Enrichment is done in blood culture, because very small numbers of bacteria are usually present in blood, enrichment of blood is done to rapidly increase bacterial count and perform subculture . This results in visible colonies are produced in solid media.
★ What media are used for subculture?
- Sub-culture done in :
- Blood agar media
- Mac Conkey’s agar media
- Chocolate agar media
★ Procedure of Blood Culture :
- Traditional method :Using liquid media on biphasic media
- Lytic method : After processing in lytic solution in solid media
- Automated : Very rapid (within 6 hours)
This is all about Blood Culture.
Sushmita Chowdhury
USTC/IAHS
2015-16
Platform academic/Shultan Mahmud Jahid