Bacteriology Basics Flashcards
PAS Stain
Stains Glycogen
Used to diagnose Whipple disease
Ziehl-Neelsen (carbol fuchsin) Stain
Stains Acid-fast organisms (Nocardia, mycobacterium)
India Ink
Stains Cryptococcus neoformans
Silver Stain
Fungi
Legionella
H. pylori
Thayer-Martin Media (VPN)
Contains Vancomycin (inhibits gram +), Polymyxin (inhibits gram -s except Neisseria), and Nystatin (inhibits fungi) Used for Neisseria species
MacConkey Agar
Lactose fermenters grow pink colonies
Obligate Aerobes
Nocardia
Pseudomonas aeruginosa
Mycobacterium tuberculosis
Bacillus (?)
Obligate Anaerobes (lack catalase and/or superoxide dismutase)
Clostridium
Bacterioides
Actinomyces
Obligate Intracellular Bacteria (Can’t Make own ATP)
Rickettsia
Chlamydia
Encapsulated Bacteria
SHiNE SKiS: Streptococcus pneumoniae Haemophilus influenzae B Neisseria meningitidis E. Coli Salmonella Klebsiella pneumoniae Group B Strep
Catalase + (degrades H2O2 before it can be converted to microbicidal products by MPO)
If you have chronic granulomatous disease (NADPH oxidase deficiency), you have recurrent infections with cat+ organisms: Staph Psuedomonas Listeria Aspergillus E. coli Serratia Candida
Urease-Positive Bugs
Cryptococcus H. pylori Proteus Ureaplasma Nocardia Klebsiella S. epidermidis S. saprophticus
Pigment-Producing Bacteria
Actinomyces israelii: yellow “sulfur” granules
S. aureus: yellow pigment
Pseudomonas aeruginosa: blue-green pigment
Serratia marcescens: red pigment (maraschino cherries)
Protein A
Expressed by S. aureus
Binds Fc region of IgG and prevents opsonization and phagocytosis
IgA Protease
Secreted by Strep pneumoniae, H influenzae B, and Neisseria (SHiN) in order to colonize respiratory mucosa
It’s an enzyme that cleaves IgA