Flashcards in Micro Basic Deck (71)
Sugar backbone with peptide side chains cross linked by transpeptidase
Support. Protects against osmotic pressure
Where is it?
What does it do?
Cell wall of Gram+
Induces TNF and IL1
What is it?
Outer membrane of Gram-
Major Surface Ag
Lipid A (induces TNF and IL1)
O polysaccharide is the antigen
What is it?
What kind of organisms
What does it contain
Space between cytoplasmic membrane outer membrane
Hydrolytic enzymes include β lactamase
Polysaccharides (except in Bacillus anthracis which contains D-glutamate)
Protects against phagocytosis
Mediates adherence of bacteria to cell surface. Sex pilus for conjugation
Keratin-like coat, Dipicolinic acid, Peptidoglycan
Resistance to heat, chemicals, dehydration
Mediates adherence to surfaces (especially foreign surfaces)
Outer layer composition in Gram+ vs Gram- bacteria
Inside to outside:
Cytoplasmic membrane, Peptidoglycan (cell wall), Capsule
Pilus, Flagellum, Lipoteichoic acid (lipids + teichoic acids)
Cytoplasmic membrane, Perplasm, Peptidoglycan, Endotoxin (LPS), Capsule
Outer layers of Mycoplasma
Membrane contains sterols and have no cell walls
Cell wall of Mycobacteria
Contains mycolic acid with high lipid content
Bugs that do not gram stain?
"These Rascals May Microscopically Lack Color"
Treponema (too thin), Rickettsia (intracellular), Mycobacteria (high lipid content in cell wall), Mycoplasma (no cell wall), Legionella pneumophila (intracellular), Chlamydia (intracellular and lacks muramic acid in cell wall)
Giemsa Stains for what organisms
"Certain Bugs Really Try my Patience"
Chlamydia, Borrelia, Rickettsiae, Trypanosomes, Plasmodium
What does it stain?
Periodic Acid Schiff Base
"PASs the sugar"
Diagnoses Whipple's Disease (Tropheryma Whipplei)
Acid Fast organisms (Nocardia, Mycobacterium)
Mucicarmine can also be used to stain thick polysaccharide capsule red
Fungi, Legionella, Helicobacter pylori
Culture Requirements for H. influenzae
Chocolate agar with factor V (NAD) and X (hematin)
Culture Requirements for N gonorrhoeae and N meningitidis
Thayer-Martin (or VPN) media
Vancomycin (inhibits Gram+ organisms), Polymyxin (inhibit Gram- organisms except Neisseria), Nystatin (inhibits fungi)
Culture Requirements for B pertussis
"Bordet for Bordetella)
Bordet-Gengou (potato) agar
Culture Requirements for C diphtheriae
Tellurite plate, Loffler's media
Culture Requirements for M tuberculosis
Lowenstein Jensen agar
Culture Requirements for M pneumoniae
Culture Requirements for lactose fermenting enterics
Pink colonies on MacConkey's agar (fermentation produces acid, turning colonies pink)
E coli is also grown on eosin-methylene blue (EMB) agar as colonies with green metallic sheen
Culture Requirements for Legionella
Charcoal yeast extract on agar buffered with cysteine and iron
Culture Requirements for Fungi
"Sab's a Fun Guy"
"Nagging Pests Must Breathe"
Nocardia, Pseudomonas aeruginosa (can use nitrates in anaerobic environment), Mycobacterium tuberculosis, and Bacillus
What doe they produce?
Where are they normally?
What antibiotics don't work on them?
"Anaerobes Can't Breathe Air"
Clostridium, Bacteroides, Actinomyces
Lack Catalase and/or SOD and are thus susceptible to oxidative damage
Foul smelling because of short chain fatty acids
Difficult to culture
Produce gas (CO2, H2) in tissue
Normal GI flora
Aminoglycosides ineffective because they need O2 to enter cell