CH7 Flashcards
1
Q
Radiation Types :
A
- Ionizing Radiation
2. Non-Ionizing Radiation
2
Q
What the wavelength of Non-Ionizing Radiation ?
A
Wavelength > 1 nm
3
Q
Example of Non-Ionizing Radiation
A
UV Light
4
Q
Mechanism of non-ionizing radiation
A
Damage DNA , Thymine dimerization
5
Q
True or false
Non-Ionizing Radiation does not penetrate plastic, glass or proteinaceous matter
A
True
6
Q
Non-Ionizing Radiation Uses
A
• Used to reduce microbial populations
– hospital rooms
– nurseries
– operating rooms
7
Q
True or false
Chemical Methods may be used on living organisms
A
True
8
Q
Factors that may effect disinfecting
A
- Concentration of the disinfectant
- What is to be disinfected
• pH
• Organic materials - Contact with microbe (easy or difficult)
- Time to be left on the surface (contact or challenge time)
9
Q
معلومات قيمة
Phenol coefficient test was the standard test used to compare the
activity of the disinfection with that of phenol
• Now the standard method is Use-Dilution test
A
.
10
Q
Methods of Evaluating Disinfectant
A
- Use dilution test
determine the bacterial survival in recommended dilution of a disinfectant and antiseptics - Disk-diffusion method (مايكرو لاب) look at the inhibition zone
11
Q
Microbes used in dilution test :
A
Three microbes are used
Salmonella choleraesuis
Staphylococcus aureus
Pseudomonas aeruginosa
12
Q
Types of disinfectants
A
- Phenol
- Chlorine
- Iodine
- Alcohols. Ethanol, Isopropanol
- Heavy Metals. Ag, Hg, Cu
- Aldehydes
- Gaseous Sterilants
- Peroxygens
13
Q
Types of phenol ?
A
1.Lister: Phenol
2. Phenolics.
O-phenylphenol used as
surfaces disinfectant
3. Bisphenols:
– Hexachlorophene,
– Triclosan
4. Biguanide :
Chlorhexidine
14
Q
Phenol uses ?
A
- Surgical disinfection in operating room
- Irritant to skin and has disagreeable odor
- Used in throat lozenges in low concentration
- Above 1% it has significant antimicrobial effect
15
Q
Advantages of Phenols as disinfectant
A
- Remain active in presence of organic compounds
- Stable
- Persist for long periods after application
16
Q
Difference between Phenolics and phenol
or
عرف Phenolics and give example
A
derivative of phenol that reduce irritation effect and increase the antimicrobial activity
Example : O-phenylphenol
17
Q
MOA of Phenolics
A
injuring the lipid containing plasma membrane, resulted in leakage of cellular content
18
Q
Phenolics derived from?
A
Coal tar; group called Cresols
19
Q
True or False
Phenolics used as surfaces disinfectant
A
True
20
Q
True or False
phenolic Active in presence of organic materials like phenol ?
A
Yes True
21
Q
Bisphenols effective against Gram +ve or Gram -ve
A
Gram +ve
Broad spectrum activity
22
Q
Example of Bisphenols and the uses
A
a. Hexachlorophene; skin lotions
b. Triclosan: Used in soaps, tooth pastes and mouth wash.
23
Q
True or False
Biguanide effective against gram-negative bacteria (not pseudomonads)
A
True
24
Q
معلومة
Biguanide not sporicidal, but have some activity against enveloped viruses
A
.
25
Example of Biguanide and the uses
a. Chlorhexidine:
I. on skin and mucous membranes.
II. for surgical hand scrubs
III. preoperative skin preparation in patients.
IV. Coating on medical devices to prevent infection and colonisation
26
Why Hypochlorite ion (OCl-) cannot enter the cell freely ?
because of the –ve charge
27
True or false
| Hypochlorite ions Don't have Germicidal action
False
28
Hypochlorite disinfectants (chlorine disinfectants) Examples and uses
1. NaOCl used as household disinfectant (Clorox®)
2. Ca (OCl)2 used to disinfect dairy equipment
3. Chlorine dioxide (ClO 2); gaseous form used for area disinfection
4. Chloramines (chlore & ammonia) are used ;
a. To sanitize glassware & to treat dairy and food manufacturing equipments
b. For treatment of water –will kill aquarium fish and so must be neutralized
c. Less effective as germicide
29
Iodine is effective against
1. bacteria
2. endospores
3. fungi
4. some viruses
30
True or False
| Iodine is Strong oxidizing agent and is Antiseptic and disinfectant
True
31
MOA of Iodine
impairs protein synthesis and alters cell membranes by forming complexes with amino acids and unsaturated fatty acids.
32
Iodine disinfectants examples
1. tincture (solution in aqueous alcohol)
| 2. iodophor (iodine and organic molecule)
33
Iodophors have
1. antimicrobial activity of iodine
2. Do not stain
3. Less irritating
34
Example of iodophor and used for
Example; Betadine which is Povidone-iodine
– Used for
1.skin disinfections and wound treatment
2.Water treatment Iodine tablets or water pass through
iodine treated resin filters
35
Alcohols. Ethanol, isopropanol how they work ?
by Denature proteins, dissolve lipids including the lipid component of enveloped viruses
36
What Alcohols. Ethanol, isopropanol can kill
Kills bacteria and fungi
37
معلومة
| Alcohols. Ethanol, isopropanol cannot kill endospores and non-enveloped viruses
.
38
optimum recommended concentration for alcohol to work best ?
70%
39
dose 60%- 95% alcohol has killing effect
Yes
40
True or False
| Pure ethanol less effective than aqueous solution
True
41
Heavy Metals. Ag, Hg, Cu are
```
biocidal or antiseptic
Oligodynamic action (small amounts are active)
```
42
Moa of Heavy Metals. Ag, Hg, Cu
```
Denature proteins (combines with sulfydryl groups on cellular
proteins)
```
43
Example of Disinfectants (Heavy Metals)
1. 1% AgNO3 was used as an antiseptic for the eyes of newborns to
protect against gonorrheal infections
– Renewed interested as a result of antibiotic-resistant bacteria; silver sulfadiazine in topical creams for burns
– Applied on the surface or within catheters (nosocomial infection)
2. Mercuric chloride-long history of use as a disinfectantmainly bacteriostatic
3. Copper –destroy green algae (algicides) in ponds and swimming pools
4. Zinc; zinc chloride in mouth wash, zinc oxide antifungal in paint
44
معلومة
| Aldehydes have effective antimicrobial action
.
45
MOA of Aldehydes
Inactivate proteins by cross-linking with functional groups (–NH2 , –OH, –COOH, —SH)
46
Examples of Disinfectants (Aldehydes
1. Formaldehyde gas
| 2. Glutaraldehyde
47
The excellent disinfectant Formaldehyde gas commonly available as
formalin, a 37% aqueous solution of formaldehyde gas. (biological specimen reservation)
48
Glutaraldehyde less irritating and more effective ??
yes
49
Disinfectant used for respiratory equipment as 2% solution (Cidex) ?
Glutaraldehyde
50
Glutaraldehyde Cidal to what type of M.O and how much time it take
bactericidal, tuberculocidal, virucidal in 10 min
| and sporicidal in 3 -10 hrs.
51
Ethylene oxide kills what
all microbes and endospores
52
lengthy exposure period for Ethylene oxide
4-18 hours
53
احكيلي عن Ethylene oxide
toxic and explosive in its pure form so usually mixed with a nonflammable gas such as nitrogen.
highly penetrating
54
Disadvantage of Ethylene oxide
suspected carcinogen (cause cancers)
55
Peroxygens
Oxidizing agents
◦ O3
, H2O2
, peracetic acid
56
what is often used to supplement chlorine in the disinfection of water
because it helps neutralize tastes and odors
Ozone
57
Give me the uses of
1. Hydrogen peroxide
2. Benzoyl peroxide
3. Peracetic acid
1. Hydrogen peroxide
1. may slow wound healing (poor antiseptic);
2. effectively disinfects objects such as packing materials and contact lens
2. Benzoyl peroxide- works against anaerobic bacteria
3. Peracetic acid-sterilant, sporicide within 30min—disinfect food
processing and medical equipment (leaves only water and traces of acetic
acids which is safe)
58
Sterility assurance
The product either to be sterile or not
59
Elimination of viable M.O from the product is depends on:
– time dependent,
– influenced by rate and duration of the biocidal action
– initial microbial contamination level
60
Sterility assurance level (SAL) it gives / equal what
10^-6
61
The quality standards of manufacturing process can be assured by combination of process monitoring criteria;
1. Bioburden determination
2. Environmental monitoring
3. Validation and in-process monitoring of sterilization process
4. Sterility testing
62
Bioburden determination
The concentration of M.Os in a material (total number per gm or ml) before sterilization
63
Bioburden determination undertaken by who
1. by suppliers
| 2. May also be checked by the recipient
64
The maximum permitted concentrations are specified in the
pharmacopoeias
65
Environmental monitoring
The levels of microbial contamination in the manufacturing area is monitored on the regular basis to confirm the number not exceed specified limit
66
TESTING METHODS for Environmental monitoring
* M.Os in atmosphere; by settle plates method or by air sampling
* Surfaces of the equipment; by overfilled plates, swabs or contact plates
67
Validation
is the process will consistently produce the results that it is intended to
68
Validation includes
1- suitability of the process
2- uniformity
3- reproducibility
69
For sterile products validation would be necessary for each of individual aspects of
1. manufacturing process
2. environmental,
3. raw materials
4. sterilization process
70
Different approaches to demonstrate adequate sterility assurance in
steam sterilization .
• General principle of validation:
1. Physical indicators
2. Chemical indicators
3. Biological indicators
71
Physical indicators
• In heat sterilization,
1. Temperature record chart, the temp. be taken from the coolest part of the
loaded sterilizer (autoclave)
2. Heat distribution and penetration within the sterilizer
• For sterilization filters;
1. Filters are subjected to bubble point pressure test to determine the pore
size and the integrity of the filter
2. Efficiency testing of HEPA filters used for the supply of sterile air to
aseptic areas
72
Chemical indicators
• Chemical monitoring of sterilization process is based on the ability of
the heat, steam or gases to alter the chemical or physical
characteristics of the chemical substances
• Chemical indicators undergo melting or color changes
73
biological indicators
• Consist of standardized bacterial spore preparations
74
Sterility testing
1. The direct inoculation method
• Two media:
A- Fluid thioglycolate (Fluid mercaptoacetat) media which contain
glucose
• Suitable for the cultivation of anaerobic organisms, incubation temp. 30-35C
B- Soyabean casein digestive (tryptone soya broth) media
• Support the growth of both aerobic bacteria (incubation temp. 30-35C) and yeast (incubation temp. 20-25C)
2. Membrane filtration method (0.45 micron)
• Is the technique recommended by most pharmacopoeia
3. Sensitive method for detecting low levels of contamination in I.V infusion fluids
• By addition of a concentrated culture medium to the fluid in its original container then sampling of the entire volume is achieved
75
Antimicrobial agents within the product Such as
preservative
It must neutralize its activity during sterility testing so that an
inhibitory action in preventing the growth of any contaminating M.O
is overcome
76
Antimicrobial agents within the product achieved by the following methods
1. Specific inactivation
2. Dilution (examples: phenols and alcohol by dilution)
3. After membrane filtration, addition of preservatives
