flash cards micro
Preserves morphology but not internal structures;
Pass slide over bunsen burner
Heat fixation
What Structure gives rigid support and protects agains osmotic pressure?
Peptidoglycan
Cell wall/Cell membrane found in which type of bacteria?
gram positive
Major surface antigen of gram negative
Outer membrane - contains the endotoxin (lipopolysaccharide). Lipid A induces TNF and IL-1
Composition of endotoxin
Lipopolysaccharide
Site of oxidative and transport enzymes in bacteria
Plasma membrane
Site of protein synthesis in bacteria
Ribosome (50S and 30S)
Space between the cytoplasmic membrane and outer membrane in gram-negative bacteria:
Periplasm
Where are beta-lactamases in bacteria?
In periplasm of gram negative bacteria
Bacterial structure protects agains phagocytosis:
Capsule
Mediates adherence of bacteria to cell surface. sex pilus forms attachment between 2 bacteria during conjugation.
Pilus/fimbria
Composition of bacterial pilus/fimbria
Glycoprotein
Provide resistance to dehydration, heat, and chemicals. Contain dipicolinic acid
Bacterial spores
Keratin like coat that gives bacteria resistance to dehydration, heat, and chemicals.
Dipicolinic acid of SPORES
Contains a variety of genes for antibiotic resistance, enzymes, and toxins
Bacterial Plasmid (made of DNA)
Mediates adherence to surfaces, especially foreign surfaces (eg: indwelling catheters)
Glycocalyx
Allow some organisms to colonize mucosal surfaces
IgA proteases
S.pneumo, N.meningitidis, N.gonorrhoeae, H.influenza
Used to directly see if an organism is present within a patient.
Direct Fluorescant Antibody Test
Used to see if patient has antibodies agains a certain pathogen.
Indirect Fluorescant Antibody Test
Structures within bacterial cell walls that are common to both gram positive and gram negative bacteria.
Flagellum, Pilus, Capsule, Peptidoglycan, Cytoplasmic membrane
Structures in cell wall unique to gram positive organisms.
Teichoic acid
Cell wall
Structures in cell wall unique to gram negative organisms
Endotoxin/LPS (outer membrane)
Periplasm
Is too thin to be visualized using traditional gram stain. Use darkfield microscopy and fluorescent antibody staining
Stain for Treponema
Is an Intracellular parasite - so does NOT stain well.
Stain for Rickettsia
Is primarily intracellular so does NOT gram stain well. Need silver stain.
Stain for Legionella pneumophilia
Is an intracellular parasite so does NOT gram stain well. Also Lacks muramic acid in cell wall
Stain for Chlamydia
Phase of bacterial growth curve where there is metabolic activity without division.
Lag Phase
Phases of Bacterial growth curve
Phases:
1) Lag phase
2) Log phase
3) Stationary phase
4) Death phase
Phase of the bacterial growth curve where there is Rapid cell division.
Log phase
Phase of the bacterial growth curve where Nutrient depletion slows growth.
Stationary phase
Phase of the bacterial growth curve where there is prolonged nutrient depletion and buildup of waste products lead to death.
Death phase
Chemical composition of exotoxins.
Polypeptides
Location of genes for endotoxins.
Bacterial chromosome
Location of genes for exotoxins
Plasmid or bacteriophage
Induces high-titer antibodies called antitoxins.
Exotoxins
Poorly antigenic
Endotoxin
Typical diseases caused by exotoxins.
Tetanus, Botulism, Diphtheria
Typical diseases caused by endotoxins
Meningococcemia, sepsis by gram negative rods
Bind directly to MHC II and T-cell receptor, activating large number of T cells to stimulate release of IFN-gamma, and IL-2.
Superantigens
S.aureus, S.pyogenes
Component attaches an ADP-ribosyl to a host cell protein (ADP ribosylation) altering protein function.
A component of AB toxin
5 Organisms that secretes ADP ribosylating Toxins.
1) Corynebacterium diphtheriae
2) Vibrio cholerae
3) E.coli
4) Pseudomonas
5) Bordetella pertussis
Toxins that inactivate EF-2
Corynebacterium diphtheriae
Pseudomonas (exotoxin A)
Inactivates elongation facto (EF-2) causing pharyngitis and “pseudomembrane” in throat.
Corynebacterium diphtheriae
ADP ribosylation of G protein stimulates adenylyl cyclase; increasing pumping of Cl- H20 into gut.
Vibrio cholerae
toxin stimulates Adenylate Cyclase
Heat labile
toxin stimulates guanylate cyclase
Heat stable
Stimulates adenylate cyclase; causes whooping cough; inhibits chemokine receptor causing lymphocytosis.
Bordetella pertussis
NT inhibited by C. tetani that causes lockjaw.
Glycine