Identification & Culturing of Microbes
Approaches in making Micro bacterial diagnosis
- Classical conventional)/ cheap but time consuming
- Direct microscopy 10 min
- Culturing 24h binary fusion, grow the bacteria, ↑ n.o of microorganism (m.o))
- Identification 24H, Using staining and different techniques to identify
- AST (antimicrobial susceptibility testing) 24h Allows you to find treatment antimicrobe against a specific microbe, and can be done using I/S Ag-Ab or NAATS such as PCR
- Immunological/ serological Ag- Ab (antigen-antibody)
- NAATS- Nucleic acid amplification test/ PCR
→ ↑ n.o of microorganism by allowing reproduction → Binary fission
Requires right environment
It’s important to provide specific growth medium (Bacteria+ fungi) with nutrients and growth factors
3 types of growth media:
- Solid media
- Agars on a petri dish, made from algae - e.g. blood agar. Agars Forms a gel like substance when made into powder mixed with water
- The microbes of Agar causes colonies (visible mass of microorganisms all originating from a single mother cell) → They get isolated and used in further analytical tests to identify the microbe
- Different types of Agar when added substance:
- i. Blood agar- add sheep’s blood
- ii. EMB agar- add methylene blue and eosin
- iii. Apopholatcitrate agar- add bile acids (cholic acids)
- iv. Chocholate agar- heat blood agar to destroy the HG in RBC
- Liquid media
- broth- no agar (used for enrichment for the microbes) ↑ microbes - causes ↑ turbidity (lumpy or cloudy)
- Biphasic → Cultures blood samples, uses both agar and broth
Agar → isolation → identification
Broth →enrichment → then becomes agar