bacteria not seen in gram stains

Question 0

spirochetes

Answer 0

darkfid microscopy

- too thin to see

Question 1

mycobacteriae

Answer 1

acid-fast stain

• too much lipin in cell wall so dye cannot penetrate (mycolic acid)
• uses carbolfuschin: red
• methylene blue: blue

Question 2

mycoplasma spp

Answer 2

none (serologies)

- no cell wall; very small

Question 3

legionella spp

Answer 3

silver stain

- poor uptake of red counterstain

Question 4

chlamydiae

• grown in cycloheximide culture
• lacks muramic acid

Answer 4

inclusion bodies

• giemsa stain
• intracellular/ very small

Question 5

ricketssiae

Answer 5

giemsa/tissue stains

- intracellular, very small