Microbiology Exam 1 Flashcard

Prokariote: 70S (50S & 30S)

Eukariote: 80S (40S & 60S)

Posative stain: Stain the cell

Negative stain: Stain the background

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)

• Detect cells belonging to the genera mycobacteria or Nocardia
• Gram stains don't work on these genera

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

• Lactobacillus
• Listeria
• Mobiluncus
• Peptostreptococcus
• Propionibacterium
• Staphylococcus
• Streptococcus

• Murein Sacculus
• Cytoskeleton

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

• Plasmids
• Pili
• Capsules
• Flagella

• Single circular chromosome of DSDNA
• Extra info may be stored in plasmids or prophages.

• 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

• Protein
• H antigen
• Chemotaxis

• Protein
• Adherence to host cell
• Antiphagocytic
• Motility
• Sex pili for conjugation

• K antigen
• Polysachurides.  Sugar + Alcohol + D AA
• Cell Surface associated
• Water soluble slime layer
• Or both

• 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

• No sterols
• site of respiration/make ATP
• Site of septum formation for cell replication

(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,

• Lipid A: Disachurides, Toxic
• Core: sugars
• O AG chain: Sugars, highly interspecies specific, highly intraspecies variable.

• Broad specificity (effect many organs)
• Endogenous & Exogenous Pyrogenic
• Activates alternative & classical compliment
• Activate hageman factor XIII
• Heat stable
• Doesn't form toxoids

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

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

1. Attachment
2. Penetration
3. Uncoating
4. Macromolecular synthesis
5. Assembly
6. Release

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

Chronic: Virus present, disease absent

Slow: Long incubation time

Rhizopod: amoeba move with pseudopoda

Flagellates: Flagella

Ciliates: Cilia

Sporozoans: complex life cycle with sexual and asexual stages

Mesophile: growth 20-55 C

Thermophiles: growth at > 55 C

Psychrophiles/ Cryophiles: growth <20 C

• 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

DNA helicase: separates dsDNA -> ssDNA

Primase: makes short ssRNA primers for DNA synthesis

DNA gyrase: relieves wind tension

Topoisomerase IV: separates chromosomes

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

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

• 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

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

• Vary in size between bacteria species
• Encode for extra functions for growth in selective media
• Can horizontally be transfered
• Genomic islands, prophages, plasmids

• Non endemic genes
• can have flanking repeats, fragments of other elements, inserted in vicinity of tRNA sequences, unstable

Kill all

(although bacterial products still present)

• Ethylene oxide
• Aldehydes
• Beta propionate
• Peroxygens

Killing most microorganisms

on inanimate objects

not spores

• Chlorine
• Phenol
• Boiling

Clean and no pathogens

Removal of many bacteria

Using heat to kill bacteria in liquids

below temperature of sterilization

Chemicals used to kill microorganisms on skin surface or mucous membrane

• Silver nitrate
• Iodine (providone/betadyne)
• Hydrogen peroxide
• Anionic detergents SLS
• alcohol

• Qualitative
• agar test for antibiotic susceptibility
• test for inhibit growth (static/cidal)
• block of antibiotic, lawn spread, observe growth

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

Isoniazide

Sulfa drugs

Penicillins

cephalosporins

Carbapenems

Bacitracin

Vancomycin

Cyclosporine

Chloramphenical

Aminoglycosides

Tetracyclines

oxazolidinones

glycyclines

Macrolides

Mupiricin

Sulfonamides

trimethoprim

fluoroquinolones/quinolones

rifampin

metronidazole

polymixin

bacitracin

• Quantitative
• kill 99.9%
• Plate and grow bacteria from MIC to see if inhibited or killed

• Quantitative
• concentration needed to kill bacteria in presence of serum
• Blood test to determine if MBC was accomplished