Chapter 9
What are the 4 basic steps of binary fission?
1. growth of cell size and increase in cell components
2. replication of DNA
3. division of the cytoplasm (cytokinesis)
4. septum formation and division of daughter cells
15 psi
121 C
autoclave
What are some examples of dermatophytes that imidazoles treat?
ring worm, tinea pedis (athlete's foot), and tinea cruris (jock itch)
Bacitracin stops...
DOUBLE POINTS: What is bacitracin derived from?
the process of the peptidoglycan precursors from coming across the membrane
(B. subtilis)
What is mixed in a open system culture for aerobic processes?
a controlled amount of air
Where do streamers (filamentous bioflims) form?
rapidly flowing water such as...
- freshwater streams
- eddies
- specifically designed laboratory cells
What is one of the oldest methods of moist-heat control of microbes, and is typically quite effective at kills vegetative cells and some viruses?
boiling
LPS structure alteration of affects polymyxins
RNA polymerase alteration to affect rifampin
These are examples of what?
target modification
what is an example of a electronic cell counting device?
coulter counter
What are some examples alkylating agents?
formaldehyde
glutaraldehyde
ethylene oxide
B-propionolactone
What temperature do mesophiles prefer?
(DOUBLE POINTS TO THE FIRST TEAM TO: draw on the whiteboard all (IN ORDER) the different types of temperature!)
20-45 C
What are bisbiguanides?
(DOUBLE POINTS: What can they do?)
cationic molecules that have antiseptic properties
(disrupt membrane and congeal cytoplasmic contents)
What is a reason that microbes make antimicrobials?
because they have competition in their own environment so they need methods of reducing them.
What are some examples of preservatives?
sorbic acid
benzoic acid
propionic acid
sulfur dioxide
nitrites
nisin
natamycin
What is a popular soil bacteria genus that is known for their natural production of a wide variety of antimicrobials?
streptomyces
If you are trying to find the growth of cells using the viable plate method and your equation is
CFU/mL = 50 x10^4 * 10 = 5.0 x 10^6
what does each part mean?
50 = number of colonies
10^4 = number of times diluated
10 = the original dilution
What are the mechanisms of action for heavy metals?
(DOUBLE POINTS: If you give all 4 examples.)
binds to and inhibits proteins
EX: mercury, silver, copper sulfate, zinc
Why does vancomycin not work on gram negative bacteria?
its inability to penetrate the protective outer membrane
What does the production of faulty proteins by aminoglycosides cause?
disruption of the cytoplasmic membrane that will kill the bacterial cell
What is something that B-lactams and vancomycin don't have in common?
(DOUBLE POINT: what kind of bacteria does it work against?)
the structure of vancomycin is not similar to that of cell-wall peptidoglycan subunits and does not directly inactivate penicillin-binding proteins
(gram-positive)
What are some examples of why it might be important to count the amount of living cells?
to know the extent of an infection
measure the effectiveness of antimicrobial compounds and medication
contamination of food and water
What are the steps of a in-use test?
1. 1 mL sample of the used disinfectant is diluted into 9mL of sterile broth medium that also contains a compound to inactivate the disinfectant
2. about 0.2mL of this mixture is them inoculated
3. look for microbial growth
4. if there are more than 5 colonies, the disinfectant is considered contaminated
What drugs inhibit protein synthesis by binding to the 50s subunits?
DOUBLE POINTS (If you add the 30s subunit drugs as well)
macrolide
lincosamides
chloramphenicol
(30s = aminoglycosides and tetracyclines)
What are the milk borne pathogens that are killed by pasteurization?
(You get points for 4, but double points if you get all 8)
Camplyobacter jejuni
Coxiella Burnetii
Listeria monocytogenes
Escherichia coli
mycobacterium tuberculosis
M. paratuberculosis
salmonella spp.
yersinia enertocolitica
(DOUBLE POINTS: what other drug is an antiprotozan and an antifungal?)
metrondiazole
(atovaquone)