Kaplan Microbiology A2

Front 1

1) Ribosomes of a prokaryote vs. eukaryote? What does this difference allow for regarding antibiotics?
2) Makeup of prokaryote chromosome? Direction of replication?
3) Nucleus of prokaryote? T or F: prokaryotic DNA has histones
4) Organelles of prokaryotes?

Back 1

1) Prokaryote: 70S (30s, 50s). Eukaryote: 80S (40s, 60s). Antibiotics can specifically target prokaryotic protein synthesis.
2) Single circular strand of dsDNA - bidirectionally.
3) No nucleus, no nuclear membrane. F - no histones (basic proteins)
4) None (ie mitochondria)

Front 2

1) What is the cell wall of prokaryotes made out of?
2) What is gram staining based upon? What color does the bacteria stain?
3) What is acid fast staining based upon? Give 2 examples of acid fast.

Back 2

1) Rigid peptidoglycan
2) Peptidoglycan in outer layer. + stains purple (big peptidoglycan layer), - stains pink
3) Ability to resist acid decolorization b/c of lots of waxes in cell wall, mycobacteria and Nocardia (partial)

Front 3

1) Only bacteria that lacks a cell wall?
2) What do chlamydia cell walls lack?

Back 3

1) Mycoplasma (ie Ureaplasma)
2) Muramic acid

Front 4

What kind of antibiotics are mycoplasma and chlamydia resistant to and why?

Back 4

Beta lactam antibiotics (penicillin, cephalosporins) mycoplasma has no cell wall, chlamydia has no muramic acid

Front 5

1) Structure responsible for bacterial mobility? Does it have a 9+2 microtubule arrangement of eukaryotes?
2) Function of pili or fimbriae, and what purpose they serve in gram - bacteria

Back 5

1) Flagella. No, don't have microtubules.
2) Attachment to host cells. Conjugation.

Front 6

Biochemical characteristics that distinguish bacteria:

1) Substrate specificity: If something grows only on Bordet Gengou, it's?
2) Ability to ferment specific sugars: If something is fermenting lactose, it's?
3) Production of unique metabolic products: if something is producing niacin, it's?

Back 6

1) Bordetella pertussis
2) E. coli
3) Mycobacterium tuberculosis

Front 7

1) What is the main structural difference between gram + and gram - bacteria?
2) Makeup of cell envelope of gram +?
3) Makeup of cell envelope of gram -?

Back 7

1) Cell envelope - all layers that enclose the cytosol of bacterium
2) Smooth, cytoplasmic membrane, peptidoglycan layer, sometimes outer capsule
3) Inner cytoplasmic membrane, periplasmic space w/ peptidoglycan in it, OUTER MEMBRANE, sometimes capsule

Front 8

Gram +:

1) Peptidoglycan wall thick or thin?
2) Outer membrane?
3) Cell wall contains what acids?
4) What binds extracellular material?

Back 8

1) Thick
2) None
3) Lipotechoic acids, some w/ teichoic (virulence factor), polysaccharides
4) Surface proteins

Front 9

Gram -:

1) Peptidoglycan wall thick or thin?
2) Outer membrane? How many layers? What anchors it to the cell membrane?
3) Where is the periplasmic space located and what does it contain?
4) What connects outer membrane to cell membrane? What is the toxic portion?
5) What is an significant component of the OUTER membrane?

Back 9

1) Thin
2) Yes. Trilayered. Lipoprotein
3) Between inner/outer membrane, peptidoglycan
4) Lipoprotein in periplasmic space
5) LPS (exotoxin) - lipid A

Front 10

1) What are bacteria's capsules usually made out of? Why do they correspond with virulence?
2) How strong are slime layers on bacteria compared to capsules?
3) What is a structure unique to prokaryotes that is a major site of antibiotic attack?
4) How does penicillin kill bacteria?

Back 10

1) Carbohydrates - capsules are antiphagocytic
2) Easily washed off, less adherent
3) Cell wall
4) Inhibits peptidoglycan synthesis (can't build cell wall)

Front 11

2 things unique to gram - bacteria?
1) 3 components of a LPS endotoxin?
2) Where is the periplasm located?
3) What allows the flow of extracellular material through a gram -'s outer membrane?
4) 4 things contained in the periplasm and its important function

Back 11

Endotoxin/periplasm
1) Lipid A (toxic), O antigen, polysaccharide core
2) Between cell membrane and outer membrane
3) Protein porin channels
4) Proteins, peptidoglycans, plasmid controlled penicillinases, hydrolytic enzymes. Osmoregulation.

Front 12

1) If present, where is the bacterial electron transport chain located?
2) What is the primary function of the plasma cell membrane?
3) What is the makeup of the plasma membrane?
4) What 2 things are associated with the membrane?

Back 12

1) Within cytoplasmic membrane
2) Osmotic barrier
3) 60% protein, 40% lipid, small carbs
4) Membrane polyribosome DNA aggregates, mesosomes (important for cell division)

Front 13

1) What does the nucleoid region of bacteria contain?
2) What 3 elements does eukaryotic DNA have that prokaryotic DNA lacks?
3) What 2 things are bacterial ribosomes made of? What prevents dissociation of ribosomes, and where are they located?
4) What do bacterial cytoplasmic granules accumulate?

Back 13

1) Circular chromosome of double stranded DNA
2) Introns, histones, nuclear membrane
3) 70% RNA, 30% protein. Polyamines (ie putrescine), located within ribosomes.
4) Food reserves - glycogen, poly-b-hydroxybutyrate (lipids), volutin granules (lipids)

Front 14

1) Spores of what bacteria are used to check the effectiveness of autoclaves? Why?
2) Spores are found in what 2 species? How do they help them survive? How do they convert into vegetative cells when the environment is more favorable?

Back 14

1) Bacillus spp., they are resistant to extreme environmental conditions
2) Bacillus, Clostridium. Resist heat, drying. Germination.

Front 15

4 phases of bacterial growth in a closed system? Describe. During which phase are antibiotics maximally effective?

Back 15

1) Lag - no growth, bacteria adapting
2) Log (exponential) - fastest rate, goes until nutrients depleted/toxic waste products accumulate
3) Plateau (stationary) - nutrients exhausted, toxins accumulate. Cell less = cell formation. Some bacteria can remain viable in nongrowing state, some can't, some start forming spores.
4) Decline - increased death rate due to starvation or sensitivity to toxins.

Antibiotics maximally effective during exponential phase.

Front 16

1) Why is oxygen toxic to obligate anaerobes? 2 examples?
2) Function of superoxide dismutase, catalase (peroxidase)

Back 16

1) Because they don't have superoxide dismutase. Clostridium, Bacillus
2) Superoxide dismutase: superoxide ion (O2-) -> hydrogen peroxide. Catalase/peroxidase: hydrogen peroxide -> water and oxygen

Front 17

1) What are fastidious bacteria?
2) Energy production requires a source of?
3) What are siderophores?

Back 17

1) Bacteria that are so host adapted, have many additional requirements
2) Carbon
3) Iron (Fe3+) chelating compounds, essential for growth in many bacteria. Binds iron then cell wall, transported inside and used for energy

Front 18

What kind of bacteria usually use fermentation?
1) What is fermentation?
2) Why can the streptococcus species only ferment? What do they have that allows them to be able to stand oxygen?
3) How much more ATP does oxidative respiration produce than fermentation?
4) What is usually the terminal electron acceptor?
5) Do a majority of bacteria use fermentation or respiration?

Back 18

Most anaerobic, and all Streptococcus species
1) Anaerobic breakdown of glucose to make ATP
2) Can't make cytochromes or catalase. Have superoxide dismutase and peroxidase, so they are facultative anaerobes
3) 20x
4) *Oxygen, nitrate, fumarate
5) Opt for respiratin over fermentation, but OBLIGATE AEROBES only respire, must use oxygen as electron acceptor (M. tuberculosis). Most versatile.

Front 19

1) Spores' resistance to radiation, drying, and disinfectants are due to what two substances in the core?
2) Vegetative growth of spores is triggered by exposure to stimuli such as?
3) What substance causes autolysis of the spore cortex? What does the spore core membrane develop into?

Back 19

1) Calcium, dipicolinic acid in the core
2) Glucose, nucleic acids, amino acids
3) Autolysin. Cell wall.

Front 20

1) What is transformation? What needs to happen for the transformation to be successful?
2) How can you induce transformation in a lab?
3) 4 medically important natural transformer species?

Back 20

1) Uptake/integration of NAKED DNA from environment. Homologous recombination w/ chromosome of the recipient
2) Salt, heat shock (this forces cells to take up plasmids with
genes)
3) Strep, Haemophilus, Neisseria gonorrhaea, Helicobacter pylori

Front 21

1) What is transduction and what are the 2 types?
2) Describe the 2 types of transduction.
3) What occurs at a higher frequency?
4) How is the gene for diptheria toxin transferred?

Back 21

1) Phage mediated transfer of DNA. Generalized, specialized.
2) Generalized - bacterial DNA accidentally packaged in phage head. Homologous recombination must occur.

Specialized - lysogenic bacteriophage incorporated in bacterial DNA excises, takes some bacterial DNA with it.
3) Specialized
4) Lysogenic bacteriophage

Front 22

1) What is conjugation? What does it require?
2) Through what vehicle does most conjugation occur?
3) What is a narrow host range plasmid?
4) What is a broad host range plasmid?

Back 22

1) Direct transfer of bacterial DNA between organisms. Cell-cell contact required.
2) Through plasmids (extrachromosomal piece of circular DNA that can replicate itself) - carries genes and virulence factors.
3) Plasmid that can exist only within a single species
4) Plasmid that can transfer between different genera of organisms

Front 23

What is the most important mechanism for widespread transfer of genetic information between bacteria? (Transformation, transduction, conjugation)

Back 23

Conjugation

Front 24

1) What the name of a plasmid that can only exist within a single species?
2) Plasmid that can transfer between different genera of organisms?
3) Plasmid that codes for genes involved in transfer between cells?
4) Plasmid that needs the help of a conjugative plasmid to transmit itself to bacteria?

Back 24

1) Narrow host range plasmid
2) Broad host range plasmid
3) Conjugative plasmid
4) Nonconjugative plasmid

Front 25

1) What are insertion sequences and what do they code for?
2) What does a transposon consist of?
3) T or F: transposons and insertion sequences need homology at the site of insertion
4) Transposons are primarily responsible for the formation of?

Back 25

1) Small 1000 bp pieces of DNA, code for transposase (allows it to jump in and out of DNA)
2) 2 insertion sequences flanking antibiotic resistance gene
3) F - don't need significant homology
4) Multiple drug resistant plasmids

Front 26

Sterilization vs. disinfection? Major distinction between the two?

Back 26

1) Sterilization = absence of all life forms. Disinfection = reductions of # of microorganisms w/ elimination of pathogens to point that instrument is safe. Sterilization can kill spores of Bacillus and Clostridium. Disinfection will not kill spores.

Front 27

5 sterilization methods?

Back 27

1) Autoclave
2) Dry heat
3) Ethylene oxide
4) Combined heat/chemical (chemiclave)
5) MIsc - "cold sterilization"

Front 28

1) T or F: disinfection will kill bacterial spores
2) T or F: disinfected instruments are sterile

Back 28

1) F
2) F

Front 29

Sterilization methods:

1) Autoclave utilizes what 2 things to sterilize? What temp? How long? Psi?
2) Dry heat (Dri-clave): Temp? How long?
3) Ethylene oxide: How long?
4) What is a chemiclave? Temp? How long? Pressure?
5) Is cold sterilization using long-term disinfectants valid?

Back 29

1) Steam heat, pressure. 121 C, 20-30 min, 15 psi
2) 160 C, 1-2 hours
3) 8-12 hours, + extra time to air out residue
4) Heat/chemical: formaldehyde + alcohol. 132 C, 20 minutes, 20-40 psi
5) No, spores not killed by long disinfectant unless used for LONG TIME (Glutaraldehyde, 12-15 hours)

Front 30

1) What is the quickest and simplest sterilization method?
2) What is the choice of sterilization for heat sensitive materials?
3) What is the choice of sterilization when sharp edges are important to maintain?
4) What are 2 main negatives of autoclave?
5) What is the main problem with dri-clave and ethylene oxide?
6) T or F: boiling can sterilize
7) T or F: cold can be used to kill microorganisms
8) T or F: cold sterilization is sterilization
9) T or F: alcohols are generally good surface disinfectants and poor soaking disinfectants

Back 30

1) Autoclave
2) Ethylene oxide
3) Dri-clave/ethylene oxide
4) Dulling, corrosion sharp edges esp. carbide steel
5) Turnaround time
6) F - Boiling disinfects only
7) F - generally ineffective
8) F - just disinfecting
9) F - poor surface b/c evaporates easily, but good soaking

Front 31

1) 3 factors that can interfere with sterilization?
2) What must you do to instruments prior to sterilization?
3) Why is it bad to have proteinaceous factors on instruments before sterilizing?
4) 4 reasons why an autoclave would fail to sterilize?

Back 31

1) Proteinaceous factors (blood/tissue), too short time, overpacking autoclave
2) Clean - can't have bloody/proteinaceous instruments
3) Can shield microoganisms from sterilizing effect of heat
4) Overpacked, proteinaceous stuff left, time insufficent/wrong cycle used, autoclave cycle interrupted (power problem, shut off)

Front 32

How do the following disinfectants kill?

1) Steam heat/most disinfectants
2) Ethylene oxide
3) Dry heat
4) Glutaraldehyde
5) Phenols
6) Alcohol
7) Detergent
8) Soap
9) Chlorhexidine
10) Mercury compounds
11) Peroxides
12) Iodine compounds

Back 32

1) Denature protein
2) Alkylates DNA
3) Protein denaturation
4) Alkylation DNA
5) Protein denaturation + disrupts cell membranes
6) Protein denaturation + disrupts cell membranes
7) Membrane disruption
8) Emulsifies fat/debris removal
9) Membrane disruption
10) Oxidation of sulfhydryl bonds
11) Oxidation of sulfhydryl bonds
12) Oxidation of sulfhydryl bonds

Front 33

Disinfectant guidelines:

1) Who must it be registered with?
2) What is the benchmark organisms it must kill, and why is this benchmark?
3) Should have what seal of approval?
4) Difference between disinfectants and antiseptics?

Back 33

1) EPA
2) M. tuberculosis - hard to kill b/c waxy cell wall w/ mycolic acids
3) ADA
4) Disinfectants used on materials/surfaces, antiseptics used similarly, but on live tissue

Front 34

What are sterilization monitors used for and what are the two types?

Back 34

Ensure process has actually killed microorganisms. Process indicator, biologic monitor

Front 35

Process indicator:

1) What is it?
2) What does it show?
3) T or F: used as legal requirement for sterilization monitoring

Back 35

1) Color change strip for autoclave
2) Temp/pressure met for autoclave run. Physical parameters only, does NOT show directly that orgs killed
3) F - not legal requirement for sterilization monitoring

Front 36

Biologic monitor:

1) What is it?
2) T or F : used as legal requirements for sterilization monitoring
3) How often must you test your autoclave?
4) How do you use this?

Back 36

1) Strip made up of spores of Bacillus - "spore strip"
2) T
3) Weekly
4) Autoclave test strip, incubate control strip - standard autoclave report: + for control strip, - for test strip

Front 37

1) What are spore forming bacteria? Which ones are used to test autoclaves? What diseases can the other one cause?
2) What does "benchmark organism" mean? What is the benchmark for sterilization? Disinfection?

Back 37

1) Bacillus and Clostridium. Bacillus used for test only. Clostridium causes pseudomembranous colitis, tetanus, botulism.
2) Standard. Sterilization - Bacillus. Disinfection - Mycobacterium tuberculosis

Front 38

Universal precautions:

1) All patients are assumed to be ____
2) All setups are done by ___, not patient
3) Barrier methods
4) What are critical instruments and how do you treat them?
5) What are semi-critical instruments and how do you treat them?
6) How must you treat handpieces? Can you disinfect?
7) What is one of the most crucial methods of infection control that can be the single most effective measure?

Back 38

1) Infectious
2) Procedure needed, not patient
3) Use
4) Pierce mucosa or enter sterile areas of the body (elevators, forceps, scalpel). Sterilized or disposed.
5) Touch mucous membranes (mouth mirror). Sterilized or high level disinfected or disposed.
6) Sterilize - can't disinfect b/c material can move backwards inside
7) Handwashing - single most effective measure.

Front 39

1) Most dental surfaces can be (disinfected/sterilized). Instruments are (disinfected/sterilized)
2) What two organisms can be especially hard to kill on surfaces?

Back 39

1) Disinfected, sterilized.
2) Mycobacterium tuberculosis, hepatitis A

Front 40

1) What were universal precautions developed in response to?
2) What happened in the 1980's?
3) T or F: standards for hepB are equally effective for HIV

Back 40

1) Hepatitis B clusters in 1970s
2) Emergence of HIV refocused infection control
3) T

Front 41

Clinically related HBV/HIV:

1) Which is easier to contract, HBV or HIV?
2) Needlestick conversion rates for HBV, HCV, HIV?
3) How must HepB vaccinations apply to workers?
4) Current HepB vaccination series?
5) T or F: you can contract diseases from vaccinations
6) What were older vaccinations made of?

Back 41

1) HBV
2) 30%, 3%, 0.3%
3) Must be offered to all workers, must be free
4) 3 injections - 0 months, 1 month, 6 months
5) F
6) Human blood products