Basic Bacteriology: Stains, Culture, Metabolics, Special Characteristics Flashcards
Name the bugs that stain poorly.
(HINT: Acronym!)
These Microbes May Lack Real Color
Treponema: Too thin to be visualized: Use dark-field microscopy and fluorescent antibody staining.
Mycobacteria: High lipid content in cell wall, detected by carbolfuchsin in acid-fast stain
Mycoplasma (no cell wall)
Legionella pneumophila (primarily intracellular) — USE SILVER STAIN!
Rickettsia (intracellular)
Chlamydia (intracellular, lacks muramic acid in cell wall)
Name the bacteria that stain with Giemsa
(HINT: Acronym)
Certain Bugs Really Try my Patience
Chlamydia
Borrelia
Rickettsiae
Trypanosomes
Plasmodium
What does PAS (periodic acid-Schiff) stain?
What do you use it to diagnose?
Acronym: PAS the sugar
Stains glycogen, mucopolysaccharides
Use to diagnose Whipple disease (Tropheryma whipplei)
What does Ziehl-Neelsen stain?
AKA Carbol fuchsin.
Acid-fast organisms: Nocardia, Mycobacterium.
What does India Ink stain?
Cryptococcus neoformans (Note: mucicarmine can also be used to stain thick polysaccharide capsule red.)
What can silver be used to stain for?
Fungi (e.g., Pneumocystis), Legionella, Helicobacter pylori
What special media is required to culture H. influenzae?
Haemophilus Influenzae:
Chocolate agar with factors V (NAD+) and X (hematin)
What special media is required to grow the neisseria species N. gonorrhoeae and N. meningitidis?
Acronym: “To connect to Neisseria, please use your VPN client.”
Thayer-Martin (or VPN) media.
Vancomycin: Inhibit gram-positive organisms
Polymixin: Inhibit gram negatives except Neisseria
Nystatin: Inhibit fungi
What media is used to isolate B. pertussis?
Bordet-Gengou (potato) agar
Acronym: Bordet for Bordetella
What media is used for isolation of C. diphtheriae?
Tellurite agar, Loffler medium.
Corynebacterium diphtheriae
What media is used to isolate M. tuberculosis?
Lowenstein-Jensen agar
What media is used to isolate M. pneumoniae?
Eaton agar, requires cholesterol
What media is used to isolate Lactose-fermenting enterics?
Pink colonies on MacConkey agar (fermentation produces acid, turning colony pink).
E. coli grown on eosin-methylene blue (EMB) agar as colonies with green metallic sheen.
What media is used to isolate Legionella?
Charcoal yeast extract agar buffered with cysteine and iron.
What media is used to isolate fungi?
Sabouraud agar
Acronym: Sab’s a fun guy!”