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Microbiology exam 1
Chapters 1-13
47
Microbiology
Graduate
03/28/2011

Additional Microbiology Flashcards

 


 

Cards

Term

Ribosomes

 

Prokariote

Eukariote

Definition

Prokariote: 70S (50S & 30S)

 

Eukariote: 80S (40S & 60S)

Term

Positive Stain

 

Negative stain

Definition

Posative stain: Stain the cell

 

Negative stain: Stain the background

Term
Gram staining process
Definition
  1. crystal violet positive stain
  2. Iodine forms a complex with violet
  3. Alcohol used to wash away
  4. safranin used to counter stain (positive)

 

Term
Acid fast staining process
Definition
  • Detect cells belonging to the genera mycobacteria or Nocardia
  • Gram stains don't work on these genera
Term

Gram + bacteria

A -> G

(1A, 2B, 2C, 1E, 1G)

Definition
  • Actinomyces
  • Bacillus
  • Bifiidobacterium
  • Clostridium
  • Corynebacterium (& other diphtheroids)
  • Enterococcus
  • Gardnerella vaginalis

 

Term

Gram + bacteria

L -> S

(2L, 1M, 2P, 2S)

Definition
  • Lactobacillus
  • Listeria
  • Mobiluncus
  • Peptostreptococcus
  • Propionibacterium
  • Staphylococcus
  • Streptococcus
Term
What determins cell shape?
Definition
  • Murein Sacculus
  • Cytoskeleton
Term

Bacterial Parts

(all bacteria have)

Definition
  • Cell Membrane
  • Genome
  • Ribosomes
  • Intracellular macromolecules
  • Almost always a cell wall
Term

Bacterial cell parts

(varies between genus & species)

Definition
  • Plasmids
  • Pili
  • Capsules
  • Flagella
Term
Bacterial chromosomal storage
Definition
  • Single circular chromosome of DSDNA
  • Extra info may be stored in plasmids or prophages.
Term
Cell surface structures
Definition
  • Made of monomeric unit repeated N number of times
  • Type II T independent antigen (High variability, low cross reactivity) IGM, can't immunize
  • Flagella, Pilli, or capsules
Term
Flagella
Definition
  • Protein
  • H antigen
  • Chemotaxis
Term
Common Pili (fimbriae)
Definition
  • Protein
  • Adherence to host cell
  • Antiphagocytic
  • Motility
  • Sex pili for conjugation
Term
Capsules/ Slime layers/ Glycocalyx, Exopolysachuride
Definition
  • K antigen
  • Polysachurides.  Sugar + Alcohol + D AA
  • Cell Surface associated
  • Water soluble slime layer
  • Or both
Term
Biofilms
Definition
  • Glob of bacteria/yeast in mucoid exopolysachuride adhering to a wet surface
  • Present in > 1/2 all Bacterial infections
  • Bacteria phenotypically change when in biofilm.
  • MDR
  • Constant release of bacteria into blood
Term
Bacterial Cell membrane
Definition
  • No sterols
  • site of respiration/make ATP
  • Site of septum formation for cell replication
Term
Periplasm structure
Definition

(peptidoglycan)

  • polymer, NAM + NAG
  • NAM forms shoots & ladders connection
  • Human lysozimes break aminosugar threads connecting NAM to NAG
  • Role in nutrient uptake, structure, chemotaxis, osmoreceptors, degradative enzymes,
Term
LPS structure
Definition
  • Lipid A: Disachurides, Toxic
  • Core: sugars
  • O AG chain: Sugars, highly interspecies specific, highly intraspecies variable.
Term
LPS virulence
Definition
  • Broad specificity (effect many organs)
  • Endogenous & Exogenous Pyrogenic
  • Activates alternative & classical compliment
  • Activate hageman factor XIII
  • Heat stable
  • Doesn't form toxoids
Term
Pathway of LPS toxicity
Definition
  1. LPS binds to human LBP in serum
  2. LPS-LBP interacts with CD14 receptors on membrane 
  3. signal transduction causes cell to release mediators

Soluble CD14 binds to endothelial cells, causes leakiness (hypotension) ARDS

Term
Sepsis, Severe sepsis, septic shock
Definition
  1. systemic inflammation
  2. activation of coagulation
  3. inhibition of fibrinolysis
  • 1 and 2 results from LPS activating factor 13. 
  • Fibrinolysis is inhibited by plasminogen activator inhibitor
  • Sepsis survivors have immunosuppresion
Term
Virus replication cycle
Definition
  1. Attachment
  2. Penetration
  3. Uncoating
  4. Macromolecular synthesis
  5. Assembly
  6. Release
Term
Persistant infections
Definition

Latent: Intermittent acute episodes, between episodes, no viral particles present

Chronic: Virus present, disease absent

Slow: Long incubation time

 

Term
Protozoa
Definition

Rhizopod: amoeba move with pseudopoda

Flagellates: Flagella

Ciliates: Cilia

Sporozoans: complex life cycle with sexual and asexual stages

Term
Basteria and temperature
Definition

Mesophile: growth 20-55 C

Thermophiles: growth at > 55 C

Psychrophiles/ Cryophiles: growth <20 C

Term
Fermentation
Definition
  • Occurs in cytosol
  • 1 2 3 or 4 carbon compounds generated, act as electron and proton acceptor turning NADH2 -> NAD+
  • Acidic carbon compound excreted from cell
Term
DNA synthesis
Definition

DNA helicase: separates dsDNA -> ssDNA

Primase: makes short ssRNA primers for DNA synthesis

DNA gyrase: relieves wind tension

Topoisomerase IV: separates chromosomes

 

Term
Synthesis of peptidoglycan
Definition
  1. Synthesis of amino sugar in cytoplasm.  UDP covalently bound to glucose as tag for converting into NAM/NAG.
  2. Assemble & move through cell membrane.  Performed by bactoprenol. 
  3. Attach new part to growing end of peptidoglycan by transglycolase enzyme
  4. Final cross linking by transpeptidase
Term
Bacterial growth cycle
Definition

Lag phase: ↑ cell volume & mass, DNA synthesis (no change in cell number)

Exponential phase: Balanced growth in size & number

Stationary phase: No net increase in cell number

Death phase: logarithmic cell death

Term

Transduction

Generalized

Definition
  • defective phage particles of both lytic and temperate (must be lytic phase)
  1. Donor genome sheered
  2. Sheered genome + viral info packaged into virus "pseudovirons/abortive phages"
  3. Gene transferred
Term

Transduction

Lysogenic conversion

Definition
  • Only by temperate bacteriophages
  • Lysogenic gives Bacteria new phenotype
  • (eg) code for toxin production

 

Term
Flexible gene pool
Definition
  • Vary in size between bacteria species
  • Encode for extra functions for growth in selective media
  • Can horizontally be transfered
  • Genomic islands, prophages, plasmids
Term
Genomic islands
Definition
  • Non endemic genes
  • can have flanking repeats, fragments of other elements, inserted in vicinity of tRNA sequences, unstable
Term
Sterilization
Definition

Kill all

(although bacterial products still present)

  • Ethylene oxide
  • Aldehydes
  • Beta propionate
  • Peroxygens
Term
Disinfectant
Definition

Killing most microorganisms

on inanimate objects

not spores

  • Chlorine
  • Phenol
  • Boiling
Term
Sanitization
Definition

Clean and no pathogens

Removal of many bacteria

Term
Pasteurization
Definition

Using heat to kill bacteria in liquids

below temperature of sterilization

Term
Antiseptic
Definition

Chemicals used to kill microorganisms on skin surface or mucous membrane

  • Silver nitrate
  • Iodine (providone/betadyne)
  • Hydrogen peroxide
  • Anionic detergents SLS
  • alcohol
Term
Kirby-Bauer disk diffusion assay
Definition
  • Qualitative
  • agar test for antibiotic susceptibility
  • test for inhibit growth (static/cidal)
  • block of antibiotic, lawn spread, observe growth

 

Term

MIC test

"Minimum inhibitory concentration:

Definition
  • Quantitative
  • In vitro test for growth inhibition
  • diluted antimicrobial vs patient bacterial isolate, observe turbidity
  • Lowest effective concentration

 

Term
Metabolic Analog
Definition

Isoniazide

Sulfa drugs

 

Term
Inhibition of cell wall synthesis
Definition

Penicillins

cephalosporins

Carbapenems

Bacitracin

Vancomycin

Cyclosporine

Term
Inhibition of protein synthesis
Definition

Chloramphenical

Aminoglycosides

Tetracyclines

oxazolidinones

glycyclines

Macrolides

Mupiricin

Term
Nucleic acid
Definition

Sulfonamides

trimethoprim

fluoroquinolones/quinolones

rifampin

metronidazole

Term
alteration of cell membrane function
Definition

polymixin

bacitracin

Term

MBC

"Minimum bactericidal concentration"

Definition
  • Quantitative
  • kill 99.9%
  • Plate and grow bacteria from MIC to see if inhibited or killed
Term
Antimicrobial Seruncidal concentration
Definition
  • Quantitative
  • concentration needed to kill bacteria in presence of serum
  • Blood test to determine if MBC was accomplished
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