1Types of Alcohols used for sterilization, disinfection, and preservation? Characteristics?
*ethanol
*isopropanol
*easy to obtain, inexpensive, rapid evaporation (limits contact time)
2What are the three levels of disinfection?
*high level
*intermediate level
*low level
3What types of organisms do high level disinfectors kill?
all organisms except high levels of of bacterial spores or prions
4What organisms do intermediate level disinfectants kill?
*mycobacteria, most viruses and bacteria
5What organisms do low level disinfectants kill?
*some viruses and bacteria
6What are some high level disinfectants?
Ethylene oxide, glutaraidehyde, formaldehyde
7What are some intermediate level disinfectants?
phenolics and halogens
8What are some low level disinfectants?
*alcohols, quaternary ammonium compounds
9What are two ways to test effectiveness of disinfectants?
*phenol coefficeint test
*use-dilution test
10How to interpret phenol coefficeint test info?
*all chemical agents compared to phenol chemical agent affect on bacteria
(#'s demonstrate how many more times it is effective)
11What class of disinfectant to Aldehydes belong to? How do they work?
*Aldehydes are high level
*inactivate proteins by cross-linking with functional groups
*considered a sterilant
12Sterilents kill endospores, T or F? ex?
True
*Aldehyde
13What are two examples of Aldehyde?
*Glutaraldehyde
*Formaldehyde
14How do gaseous sterilants work?
*protein denaturation
*crosslinking proteins functional groups
15Three main types of gaseous sterilants:
*Ethylene oxide
*Cholorine Dioxide
*Hydrogen Peroxide Vapor (HPV)
16Four main types of Intermediate Disinfectants?
*Halogens
*Peroxygens
*Phenol (and derivitives)
*Biguanides
17Classification of Halogens as disinfectant and mode of action?
*Intermediate Disinfectant
*oxidizing agent
18Examples of Halogens?
*chlorine and iodine
19Classification of Peroxygens and mode of action? ex)
*intermediate disinfectant
*oxidizing agent
*Ozone O3
*H2O2
*peracetic acid
20Peroxygens antimicrobial properities depends on?
*phase and concentration
21Classification of Phenols, mode of action?
*intermediate disinfectant
*disrupts plasma membrane
*inactivates enzymes
*denatures proteins
22Types of Phenols?
*Phenolics
*Lysol
*Bisphenols
*Hexacholorphene
*Triclosan
23What are Biguanides and mode of action?
*disrupts plasma membrane due to amphipathic nature
24Examples of Biguanides?
Chlorhexidine
25Alcohol disinfectant classification and types? Mode of action?
*low level disinfectant
*denatures proteins and dissove lipids
*ethanol and isopropanol
26What are tinctures? why?
ethanol is used as the solvent instead of water in the low level disinfectant
*helps improve disinfectant properities of solute
27What is the ideal range of alcohol?
60-90% range (no growth after 10 seconds)
28What are surfactants?
*surface active agents
*considered mechanical removal of microbes
29What are three categories of surfactants? Action of each?
*soap (degerming)
*acid-anionic detergents (sanitizing)
*Quarternary ammonium compunds (cationic detergents) Bactericidal
30Action of Acid-anionic detergents?
*sanitizing (disrupt plasma membrane)
31Action of Quarternary ammonium compounds or Cationic detergents?
*bactericidal (denature proteins, disrupts plasma membrane)
32Mechanism of action with Heavy metal disinfectants?
*oligodynamic action (not fully understood)
*denatures proteins
33Types of Heavy metal disinfectants?
*Ag, Hg, Cu
34Why would Ag or Cu be imbedded in surfaces?
*acts as long acting antimicrobial
35What is used as a chemical food preservative?
*Organic acids
*nitrite
*Antibiotics
36How to organic acids perserve food?
*inhibit metabolism of microbes
*control molds and bacteria in foods and cosmetics
37What are types of organic acids used in food preservation?
*sorbic acid
*benzoic acid
*calcium propionate
38How do nitrites chemically preservative food?
*prevents endospore germination
39What antibiotics prevent spoilage of cheese?
Nisin and Natamycin
40Antimicrobial agents exhibit ___toxicity?
Selective toxicity
41What impacts an Antimicrobial agents toxicity?
*characterisitcs of the organisms
*concentration of the agent
*time of exposure
42T or F, susceptibililty of microbes to different agents can change over the course of a single organisms life cycle?
True
43What is the most reisistant microbe? Why?
*Prions
*they are not alive (protien) so resistant to digestion
44What is the least resistant microbe? Why?
viruses with lipid envelope
*possess no machienary to repair damage to envelope, contain no phospholipid protection
45What chemical agents work against endospores?
bleach and cyclohexidine
46why are gram-negative bacteria more resistant than gram-pos?
*gram neg have two membrane system than pos one mem
47Why is gram pos thick cell wall not make it more resis than gram neg?
*thick cell wall helps with resilence to water environments (hypotonic solutions)
48What chemicals work good against mycobacteria?
*alcohols
*glutaraldehyde
49What are two ways to evaluate chem methods of microbial control?
*disk-diffusion method
*disk diffusion assays
50Brief description of Disk-Diffusion method?
*bacterial growth (lawn) on agar surface
*(filter paper discs soaked in antibiotic material)
*evaluate zones of inhibition
51What is the Kirby Bauer test?
*Mueller Hinton agar plate
*lawn of bacteria
*observe zones of inhibition (use standardized chart to evaluate sensitivity) and MIC values
52What is MIC values?
minimum inhibitory concentration
53Describe Synergism?
*the effect of two drugs (together) is greater than the effect of either alone
54Describe Antagonism?
*when the effect of two drugs together is less than the effect of either alone
55What is MIC?
Minimum inhibitory concentration
*lowest antibotic concentration that inhibits bacteria growth
56What is MBC?
*minimal bacteriocidal concentration
*the lowest concentration where 99.9% of bacteria are killed
57What is Therapeutic dose?
*minimun dose per kg of body weight that stops growth
58What is toxic dose?
*maximum dose tolerated by the patient
59What is chemotherapeutic index?
*ratio of toxic dose to therapeutic dose
60A higher chemotherapeutic index means what?
*higher=safer the drug