MICROBIAL CONTROL Flashcards
1
Q
refers to microbial contamination
A
SEPSIS
2
Q
the absence of significant contamination
A
ASEPSIS
3
Q
Killing C. botulinum endospores
A
COMMERCIAL STERILIZATION
4
Q
Removal of pathogens
A
DISINFECTION
5
Q
Removal of pathogens from living tissue
A
ANTISEPSIS
6
Q
Lower microbial counts on eating utensils
A
SANITIZATION
7
Q
Kills microbes
A
BIOCIDE/GERMICIDE
8
Q
Inhibiting, not killing microbes
A
BACTERIOSTASIS
9
Q
Kills bacteria
A
BACTERIOCIDAL
10
Q
EFFECTIVENESS OF ANTIMICROBIAL TREATMENT
DEPENDS ON:
A
- Number of microbes
- Environment
- Time of exposure
- Microbial characteristics
- Condition of microbes
11
Q
T or F
high population = shorter time for
healing
A
False
-longer time for healing
12
Q
MECHANISM OF ACTION OF ANTIMICROBIAL
CONTROL AGENTS
A
CONTROL AGENTS • Alteration of membrane permeability • Damage to proteins • Damage to nucleic acid • Interfere with metabolic pathways
13
Q
-very commonly used physical method of microbial control
A
Heat
14
Q
Time to kill all cells in a culture at a
given temperature
A
THERMAL DEATH TIME (TDT)
15
Q
Lowest temperature at which all cells in
a culture are killed at a given time
A
THERMAL DEATH POINT (TDP)
16
Q
type of heat which denatures proteins
A
Moist heat
17
Q
Equivalent treatments for pasteurization
A
● 63C for 30 mins.
● High-temperature short time: 72C for 15 secs.
● Ultra-high temperature: 140C for <1 sec
18
Q
type of heat which kills by oxidation
A
○ Flaming
○ Incineration
○ Hot-air sterilization
19
Q
Equivalent treatments for dry heat
A
Hot air: 170C, 2hrs
Autoclave: 121C, 15 min
20
Q
● removes microbes
● for materials not conducive to be subjected in high
temperatures
A
Filtration
21
Q
Examples of techniques which uses LOW TEMPERATURE as microbial control
A
● Refrigeration
● Deep freezing
● Lyophilization
22
Q
● prevents metabolism
● drying and removing moisture
A
DESICCATION
23
Q
causes Plasmolysis
A
OSMOTIC PRESSURE
24
Q
Electromagnetic spectrum, shorter wavelength
means great energy and can penetrate further
A
Radiation
25
IONIZING RADIATION:
Xrays, gamma
| rays, electron beams
26
NON-IONIZING RADIATION:
UV
27
is derived from radurization,
combining “radiation” with the stem of
“durus”, the Latin word for hard, lasting
Radura
28
Often chemical methods are compared to
_______
- grandfather of all chemicals used for microbial control
PHENOL
29
Phenol coefficient:
| MORE EFFECTIVE THAN PHENOL:
>1
30
LESS EFFECTIVE THAN PHENOL:
<1
31
PRINCIPLES OF EFFECTIVE DISINFECTION
● Concentration of disinfectant
● Organic matter
● pH
● Time
32
Disks of filter paper are soaked with
various chemicals and placed on an
inoculated agar plate
Disk Diffusion Method
33
T or F
In disk diffusion method, The greater the zone of
inhibition the better
True
34
Technique in which containers holding
identical volumes of broth with antimicrobial
solution in incrementally (usually
geometrically) increasing concentrations are
inoculated with a known number of bacteria.
Broth Dilution
35
carbolic acid
PHENOL
36
The MOA of Bisphenols
Disrupts plasma membranes
37
Example of biguanides
chlorhexidine
38
```
Forms bleach (hypochlorous acid) when added to
water.
```
Chlorine
39
● More reactive, more germicidal
| ● Alters protein synthesis and membranes
Iodine
40
Iodine solution with alcohol
Tincture of iodine
41
MOA of Alcohols
Denature proteins, dissolve lipids
42
Alcohols are easily inactivated by ______
organic debris
43
MOA of heavy metals
Denatures proteins by metal ions
combining with sulfhydryl (-SH) and other
groups
44
against chlorophyll containing
| organisms → Algicides
Copper
45
Mercury-containing used for skin lesions
Thimerosal HgCl2
46
Antiseptic for eyes of
| newborns
AgNO3
47
ZnCl2 in mouthwashes; __ in antifungal
ZnO
48
Major purpose of soap
Mechanical removal and use
| as wetting agent
49
→ Anion reacts
with plasma membranes. Nontoxic, noncorrosive, and fast acting. Laundry soap,
dairy industry.
Acidic-Anionic detergents
50
```
→ Quaternary
ammonium compounds (Quats). Strongly
bactericidal against wide range, but
especially Gram (+) bacteria
```
Cationic detergents
51
______prevents endospore germination (Can
combine with chemicals in stomach to form
nitrosamine
Nitrite
52
Inactivate proteins by cross-linking with functional
| groups (-NH2,-OH, -COOH, -SH)
ALdehydes
53
Sweet smelling gas. Used for
fabrics, clothes & plastics - materials that are not
amenable to being heated.
Ethylene oxide
54
Endospores are
| best dealt by the ______
autoclave
55
the killing or removal of all viable
| organisms within a growth medium
Sterilization
56
effectively limiting microbial growth
Inhibition
57
the treatment of an object to
| make it safe to handle
Decontamination
58
directly targets the removal of all
| pathogens, not necessarily all microorganisms
Disinfection
59
is the most widely used method of controlling
| microbial growth
HEAT STERILIZATION
60
Amount of time required to reduce viability
| tenfold is called the _______
decimal reduction time
61
is a sealed device that uses steam
| under pressure.
autoclave
62
is the process of using controlled heat to reduce the
| microbial load in heat-sensitive liquids
PASTEURIZATION
63
has sufficient energy to cause modifications and
| breaks in DNA
Uv
64
T or F
| UV can penetrate solid, opaque, or light-absorbing surfaces
False
| -it cannot penetrate
65
- Electromagnetic radiation that produce ions
and other reactive molecules
- Generates electrons, hydroxyl radicals and
hydride radicals
Ionizing radiation
66
approved by the WHO and is
used in the USA for decontamination of food
particularly susceptible to microbial
contamination e.g. (hamburgers, chicken,
spices)- may all be irradiated
Radiation
67
Filtration can be accomplished by
| syringe, pump, or vacuum
MEMBRANE FILTERS
68
is the smallest amount of an agent
needed to inhibit growth of a
microorganism
MINIMUM INHIBITORY CONCENTRATION
| MIC
69
Antimicrobial agents added to filter
| paper disc
DIFFUSION ASSAY
70
Antimicrobial drugs are classified on the basis of
- Molecular structure
- Mechanism of actions
- Spectrum of antimicrobial activity
71
Alter membrane permeability (cell wall synthesis)
Penicillin
| cephalosphorins
72
Damage proteins
| protein synthesis-50s
Erythromycin
Chloramphenicol
Clindamycin
Lincomycin
73
Damage proteins
| protein synthesis-30s
```
Tetracyclines
Spectinomycin
Streptomycin
Gentamicin
Kanamycin
Amikacin
Nitrofurans
```
(KANGTSS)
74
Example of DNA gyrase inhibitor
quinolones
75
Example of RNA elongation
Actinomycin
76
DNA directed RNA polymerase MOA is
| mainly on the
DNA
77
taken by the bacteria in order to metabolize it to
| produce tetrahydrofolate.
PABA (para amino benzoic acid)
78
Folic acid metabolism group interfere with
DHF
| and THF
79
is the ability to inhibit
or kill a pathogen without affecting the
host.
Selective toxicity (Paul Ehrlich)
80
discovered by Gerhard
| Domagk in the 1930s
SULFA DRUGS
81
Isoniazid is a growth analog effective
| only against ____
Mycobacterium
82
SULFA drugs interfere synthesis of_____
Mycolic acid
83
are one of the most important groups
| of antibiotics of all time
B-lactam antibiotics
84
Penicillins are primarily effective against gram_
+
85
Penicillins target the ____
Cellwalls
86
Semisynthetic penicillins:
```
● Methicillin (acid-stable)
● Oxacillin (acid-stable)
● Ampicillin (broad spectrum & acid
stable)
● Carbenicillin (broad spectrum & acid
stable)
```
87
- Produced by fungus Cephalosporium
| - Same mode of the action as the penicillins
CEPHALOSPORINS
88
Cephalosporins are commonly used to treat_______
Gonorrhea
89
are antibiotics that contain amino
| sugars bonded by glycosidic linkage
Aminoglycosides
90
Streptomycin can only be given via _______
injection
91
contain lactone bonded to sugars
Macrolides
92
Tetracyclines contain ____rings
four
93
○ Also produced by Streptomyces (which is a fungus)
○ Used to treat gram-positive bacterial infections
○ Forms pores in cytoplasmic membrane
Daptomycin
94
○ New structural class of antibiotic (Figure 26.25)
○ Broad-spectrum, effective against MRSA, and
vancomycin-resistant enterococci
Platensimycin
95
bind directly to RT and inhibit reverse
| transcription
Non-nucleoside reverse transcriptase inhibitors
| NNRTI
96
inhibit the processing of large
| viral proteins into individual components
Protease inhibitors
97
prevent viruses from successfully
| fusing with the host cell
Fusion inhibitors
98
Two categories of drugs successfully limit
| influenza infection
○ADAMANTANES
| ○NEURAMINIDASE INHIBITORS
99
small proteins that prevent viral
multiplication by stimulating antiviral proteins in
uninfected cells
Interferons
100
Acquired ability of a microorganism to resist the effects
of a chemotherapeutic agent to which it is normally
sensitive
Antimicrobial drug resistance
