Microbiology Flashcards
Transpeptidase
Penicillin binding protein found in peptidoglycan
Cell wall is thicker in
Gram positive bacteria
Cell wall chemical composition
- Peptidoglycan
2. Lipoteichoic acid (induces TNF and IL-1)
Outer membrane function
Site of endotoxins (LPS)
Outer membrane chemical composition
Lipid A (induces TNF and IL-1); O polysaccharide is the antigen
Plasma membrane
Site of oxidative and transport enzymes
Periplasm chemical composition
B-lactamase
Pilus/fimbria chemical composition
Glycoproteins
Flagellum chemical composition
Protein
NB: increase flagellum in proteus (swarming motility)
Spore chemical composition
Dipicolinic acid; peptidoglycan
Plasmid function
Contains a variety of genes for antibiotic resistance,menzymes, and toxins.
Capsule chemical composition
Polysaccharide layer (except Bacillus anthracis, which contains D-glutamate)
Glycocalyx function
Slime layer that mediates adherence to foreign surfaces especially indwelling catheters (staph epi.)
Bacterial structures unique to gram negative bacteria
- Porin
- Endotoxin/LPS (outer membrane)
- Periplasmic space (B-lactamase location)
Bacterial structure unique to gram positive
Lipoteichoic acid (cell wall)
TNF & IL-1 induced by
Lipoteichoic acid (gram positive)
Lipid A (LPS- gram negative)
Bacteria that produce endospores
- Bacillus
2. Clostridium
Spirochetes
Borrelia
Leptospira
Treponema
*Axial filaments
No cell wall
Mycoplasma
Ureaplasma
*contain sterol
Changes pili to evade host response
N.gonnorhea
Biofilm producing bacteria
S.epidemidis
Viridans step
Pseudomonas
Nontypable H.influenza
Gram stain limitations
These Microbes May Lack Real Color Treponema Mycobacteria Mycycoplasm Legionella Rickettsia Chlamydia
Giemsa
Chlamydia, Borrelia, Rickettsia, Trypanosomes Plasmodium
Certain Bugs Really Try my Patience
PAS (periodic acid-Schiff)
Whipple diseae (Tropheryma whipplei). Stains glycogen
Ziehl-Neelsen (carbol fuchsin)
Acid fast bacteria (Nocardis, Mycobacteria)
Protozoa (Cryptosporidium oocysts)
NB: alternative is auramine-rhodamine stain for screening (apple green=positive acid fast)
India ink
Cryptococcus Neoformans
Silver stain
Fungi (pneumocystis)
Legionella
H.pylorie
Media for H.influenza
Chocolate agar Factors V (NAD) and X (hematin)
Media for Neisseria
Thayer-Martin
Vancomycin (inhibits gram +ve)
Trimethoprim, colistin (inhibits gram -ve except Neisseria)
Nystatin (inhibits fungi)
Media for Bordetella Pertussis
Bordet-Gengou agar (potato)
Regan-Lowe medium (charcoal, blood, and antibiotics)
Media for C.diptheriae
Cysteine Tellurite agar, Löffler medium
Media for M.pnuemoniae
Eaton agar (requires cholesterol)
Lactose-fermenting enterics media
MacConkey agar (selective for gram -ve and differential)
Pink colonies
Media for E.coli
Eosin-METHylene blue (EMB) agar
Green metallic sheen
Media for Legionella
Buffered Charcoal Yeast Extract
Fungi Media
Sabouraud agar
Aerobes
Nagging Pests Must Breathe
Nocardia
Psedomonas
MycoBacterium TB
Anaerobes
F ABC Fusobacterium Actinomyces Bacterioides Clostridium
Antibiotic that is ineffective against anaerobes
Aminoglycosides (require O2)