Flashcards in Lecture 6 - Gastrointestinal Disease 2 Deck (26):
What can light microscopy show us when investigating GIT disease?
'Pus' cells --> inflammation
What can electron microscopy show us when investigating GIT disease?
Describe the process of Latex agglutination / EIA / ELISA?
1. Known Ab place on bottom
2. Unbound sites blocked
3. Antigen added from sample
4. Known Ab with conjugated enzyme added
5. Substrate for enzyme added
6. Colour is read
What are routine media?
What are specialised media?
What are enrichment media?
How would we first identify significant isolates?
How would we confirm the pathogen?
How do we compare strains?
How do we look for specific virulence determinants?
What are the features of Enterobacteriaceae?
What are the features of Vibrio (Vibrionaceae)?
GN (curved) R
What are the features of Campylobacter (Vibrionaceae)?
GN (curved) R
What does MAC allow to grow?
How do we differentiate between E. coli, Shigella and Salmonella on MAC?
Lactose fermenters --> pink (E. coli)
LNF --> Yellow / colourless (Salmonella, Shigella)
What does DCA allow to grow?
Similar to MAC
Salmonella: black dot
What do we do after culture on routine media?
Look for suspicious colonies:
LNF: Shigella, Salmonella, Yersinia
These are not normal flora of the gut
What does Selenite broth allow to grow?
Salmonella spp. --> brick red
What does BP select for?
Staphylococcus aureus --> black with zone of clearing
What does BCSA select for?
Bacillus cereus --> blue + white precipitate
What does CAMP select for?
Describe how an agglutination reaction works
Bacteria + antibody --> visibly agglutinates
What is phage typing used for?
To determine the source: same phage types --> same source?
Describe the process of phage typing
1. Lawn culture of bacteria applied to plate
2. Panel of phages dotted onto a grid
3. Incubation of plate
4. Pattern of areas of lysis read
5. Phage type assigned
What bacteria is phage typing used for?