Final Exam Flashcards
1
Q
cleaning
A
removal of dirt , dust , food , grease , particles, feces, vomit etc.
2
Q
sterilization
A
removal of all living cell and endospores
should only apply to object as we would be dead if were sterile
technically we include viruses
3
Q
disinfection
A
removal of microorganisms from inanimate surfaces
- does not include endospores and some viruses
ex. chemical compounds like bleach, alcohol
4
Q
antisepsis
A
removal of microogranims form living tissues such as skin or mucous membrane
- does not include endospores and some viruses
ex.mouth wash, alcohol
5
Q
sanitation
A
reducing microbe numbers to “safe” levels
-safe= public health standard
6
Q
bacteriostatic agents
A
- Slow or stop metabolism or reproduction
- Bacteriostatic agents inhibit bacterial growth.
- Fungistatic, virustatic, algistatic, etc.
7
Q
bactericidal agents
A
- Lethal effects
- Bacteriocidal agents kill bacteria.
- Fungicides, virucides, algicides, etc.
8
Q
External factors that influence microbial control
A
- population size
- composition of the population ( who is present)
- concentraiton/dose of agent
- contact time
- location
- temperature
9
Q
Mode of action of antimicrobial processes
A
- Inhibit some cell process
1. DNA replication
2. Transcription
3. Translation
4. Metabolism - Alteration of membrane permeability
- Damage to the cell wall or inhibition of wall synthesis
- Damage to DNA or proteins
10
Q
List of how hard it is to remove microbes (1 easy 10 hardest)
A
- Enveloped virus
- most gram-postive bacteria
- noneveloped viruses
- fungi and fungal spores
- most gram-negative bacteria
- protozoan trophozoites
- protozaon cyst
- staphlyococcus and pseudomonas ( including biofilm)
- myobacterium
- bacterial endospores (including biofilm)
- prions
11
Q
protozoa of medical interest
A
- They have two “lifestyles”
Trophozoites
Cysts - Depends on protozoa, which stage is
infective - Some protozoa never form cysts, others
alternate between the two depending on
environmental conditions
12
Q
Physical Control Methods
A
Outcomes:
disinfection, sanitization, and sterilizaiton
usually only used on inanimate objects, liquids or gases
- temperature, radiation,filtration
13
Q
Physical Control method
temperature
A
Hot
- moist heat
- pasteurization
- dry heat
Cold
- refrigeration
- freezing
14
Q
Effects on microbes due to cold
A
- -static
- Low temperatures reduce the speed of
cellular activities - Some pathogens are resistant /
tolerant to refrigeration (Listeria monocytogenes)
15
Q
Effects on microbes due to heat
A
Denatures nucleic acids, proteins, and lipids
* inhibiting cellular processes
Advantages
* Quick, cheap, and no toxic residues
Disadvantages
* Some heat processes do not remove endospores
* Not everything can be heated to “kill” temperatures
16
Q
Effects of moist heat- boiling
A
Temperature and Exposure Time
* 100C for 1-3 min for drinking
* 100C for 20 min for an object
- Disinfection / Sanitization
Example: Autoclave
* Temperature and exposure time:
* 121°C and 15 lb. pressure for 20 min.
* Outcome: Sterilization
17
Q
Moist Heat-Canning
A
- High Temperature and Pressure
- If not done well Clostridium
botulinum endospores will survive
and cause food poisoning
18
Q
Clostridium botulinum
A
- Gram positive rod
- Endospore former
- Strict Anaerobe
- Neurotoxin
19
Q
Pasterurization
A
- Developed by Louis Pasteur
- Thermal process that is carried out in liquids (usually food) to reduce
the presence of pathogens - Disinfection / Sanitization
20
Q
Dry Heat
A
For materials that cannot be exposed to water or moisture
* Metals
Requires higher temperatures and exposure times
* Ovens (16 hours at 121 ° C !!!)
* Incineration – flaming loop
Sterilization
21
Q
Radiation
A
- Damages DNA structure, preventing DNA
replication and transcription
Ionizing and Non-ionizing
22
Q
Ionizing radiation
A
used in medical equipment and food
preservation
* Gamma
* X-rays
* Sterilization
23
Q
non-ionizing radiation
A
disinfection of surfaces, gases and
fluids
* Ultraviolet light
24
Q
Filtration
A
- Mechanical control
- Small pores of 0.2µm
- Removal of microorganisms (Has no effect on microbes)
- It is used with materials that usually
cannot go through other processes - Sterilization
25
Pratical concerns in microbial control and how circumstance dictate selection.
1. What is the desired outcome?
- Does it need sterilization?
2. Is the item to be reused?
* Can the item withstand heat, pressure, radiation, or chemicals?
3.Will the control method penetrate to the necessary extent?
4.Is the method cost- and labor-efficient, and is it safe?
26
What is a chemical control?
* Use of chemical compounds for the control of microorganisms
* It is the most used type of control
* The effectiveness is affected by temperature, exposure time, and
amount of organic matter (dirt) in the environment
* The concentration and age of the chemical also affect its effectiveness
27
CDC levels of disinfection chemical compounds
high: ethylene oxide,glutaraldehyde , formaldehyde
intermediate: phenolics, halogens
low: alcohols , quaternary ammonium
28
CDC level high removes
Vegatative bacteria cells
myobacteria
endosopores
fungi
viruses
29
CDC level intermeditate removes
Vegatative bacteria cells
myobacteria
fungi
viruses
30
CDC level low removes
Vegatative bacteria cells
fungi
viruses (some )
31
Ethylene Oxide
* Gas
* High level- sterilization
* Damages proteins and DNA
* Negative: in high concentrations, it is
explosive and poisonous
* Used for medical equipment and products
-Sutures, catheters, artificial valves, plastics
-Things that cannot be autoclaved or heated
32
Hydrogen peroxide
* Liquid
* Intermediate to high-level
-Can sterilize inanimate objects in certain
concentrations
* Damages macromolecules by producing free
radicals
* Most effective against anaerobes
* Works well with organic materials
* Toxic if ingested, inhaled, or comes into contact
with the skin or eyes
33
Halogens
* Gaseous or liquid
-Iodine, Chlorine, Fluorine, etc
* Intermediate level
*-Some are low-acting against endospores*
* Damage proteins
* Effective against bacteria, fungi, many viruses,
protozoa, protozoal cysts, fungal spores
* Chlorine can tolerate some organic material,
but can be corrosive.
34
Alcohols 70%-90%
* Liquid
* Low activity
* They damage proteins and the plasma membrane.
* Bactericide, fungicide, and inactivates enveloped viruses.
-It does not eliminate spores.
* Positive: leaves no chemical residue
* Negative: evaporates quickly, leaving little contact time with microbe
35
Quaternary Ammonium
* Liquid
* Low activity
-Activity lowered in the presence of
organic matter
* Damages membranes (detergent)
* Also used for sanitation
36
Soaps
* Solid or liquid
* Very low activity
* They only remove microbes
* According to the CDC,
antibacterial soaps are no
more effective than regular
soap and water
* Non-toxic
37
What is antibiotic and what was their orgin?
Chemical drug that is antagonist to the growth of bacteria
* Alexander Fleming in England - 1929
-Accidental discovery
-Produced by Penicillium mold
* Roadblock
-Low production of penicillin by mold
38
Penicillin production
1929 - Discovery by Fleming
1938 – Research on Penicillin starts at Oxford
1939 – WWII starts
1940 – Animal Trials successful
1941 – Scientist Travel to Peoria Il to work on mass
production
1942 – Just enough for 10 patients
1943 - Mary Hunt finds cantaloupe with golden mold
1944 – Enough production for soldiers on D-Day
1945- WWII ends, 646 billion units/year, Nobel Prize
39
History of anitbiotic industry
* From 1940’s until 1980 --
discovered and commercialized
dozens of antibiotics
* 1980s – “we’ve conquered
infectious disease”
* 1980s – more lucrative diseases
apparent
40
Antibiotic mechanism of action
-Peptidoglycan synthesis ( cell wall or membrane inhibitors)
-metabolic inhibitors
-DNA replicaiton inhibitors
-RNA polymerase inhibitors
-Protein synthesis inhibitors ( 50s or 30s ribosome subunit)
can be cidal or static
41
Toxicity and other side affects of antibiotics
* May harm body tissues and
organs
* Disrupt the normal microbiota
* Induce allergies and
hypersensitivities
* Contributes to antibiotic
resistance
42
Spectrum of activity of antibiotics
Different antibiotics can target vairous types of bacteria having wide net, and then narrow antibiotics that allow speicific bacteria to be targeted.
43
Explain what is antibiotic resistance and why it is a problem
* Changes in DNA
*Selection
* Multiplication of resistant
cells
* = EVOLUTION
* DNA replication mistakes
* Directional selection
* One phenotype has the
highest fitness. The bell curve
shifts towards the more fit
phenotype.
44
Stategies for antibiotic resitance
1. Keep antibiotics out of the
cell.
2. Prevent antibiotics from
binding the target.
3. Dislodge an antibiotic
already bound to its target.
45
Keep antibiotics out of the cell
* Destroy the antibiotic
-enzyme specifically destroys
penicillin
* Pump the antibiotic out of the cell
-Membrane pumps bail drugs out of
cell faster than they can enter.
* Decrease membrane permeability
46
prevent antibiotics from binding the target
* Modify the target so that it
no longer binds the antibiotic
* Make more copies of target
* Alternate pathway/enzyme
47
dislodge an antibiotic already bound to its target
* Newly discovered!
* Ribosome protection or
rescue.
-proteins that bind to
ribosomes and dislodge
macrolide antibiotics
48
Identify where we can find microorganisms.
Everywhere on earth and all levels of cycling CHONPS
49
Define and identify microbial interactions with the environment and
other organisms.
Biogeochemical Cycling
Precipitation Cycle
50
Describe the importance of microbes to the health of the planet and
ecosystems.
Present across the bioshpere with vast metabolic diveristy allowing the processing of CHONPS which allows the use and recycling of all nutrients.
51
Correlate nutritional types, oxygen relationships, and metabolic
processes to global biogeochemical cycles.
methanogenesis- lithotrophs
primary producers- autotrophs
consumers- heterotrophs
decomposers- everyone
52
Describe the interactions among the biogeochemical cycles.
Sum of the microbial, physical, and
chemical processes that drive the flow
of elements.
Microbial metabolism
* Nutritional types
*Electron Donors
*Carbon source
* Relationship with oxygen
** Electron acceptor*
Many microbes working together
* Good things …
* Bad things …
53
Microbiota
All the microbes found in the
human body
* Estimates of microbiota numbers
vary ...
* ~ same number of bacteria as
human cells
* 6 pounds of microbes ... brain
weighs 3 pounds ...
5
54
Compare the composition of microbiomes from different areas of the body
Human bodies are composed of various pH levels, tempature, salinity, moisture, oxygen concentration all these factors play a role in which microbes may be present in each region
55
Identify the benefits of the microbiota
Digesting food (plant fiber)
Vitamins (B and K)
Help develop intestines
Help develop and enhancing function of the
immune system
Interfering with colonization by
pathogens by:
* Competing for attachment sites
* Competing for food sources
* Synthesizing antimicrobial compounds
56
Explain the intercommunications between human cells and microbiota
* Microbial metabolites in
blood and urine affect
host gene expression
* Human neurotransmitters
and hormones change
bacterial gene expression
* Gut microbiota produces
compounds that have
neurotransmitter activity
* Microbiota can affect
behavior !!!
* Correlation between
microbiota and anxiety,
moods, autism, Parkinson’s
57
Identify possible effects of a deficient microbiota
Hygiene Hypothesis
* Lack of exposure to microbes during
childhood
*increases susceptibility to allergies and
asthma in adulthood
delayed or incorrect development of the
immune system*
People in developing countries have a larger and
more diverse microbiota
58
Identify factors that affect the microbiota
clean water
cesarean deliveries
use of preterm antibiotics
reduced breast feeding
smaller family size
widespread antibiotic use
increased bathing and showering + antibacterial soaps
use of mercury amalgam dental fillings
59
Mention how the microbiota could be modified and recovered
microbiota transplants
