Week3 Control Of Micobial Growth

Question 1

Who and What is the CDC?

Answer 1

The Center for Disease Control collaborates to create the expertise, information, and tools that people and communities need to protect their health - through health promotion, prevention of disease, injury and disability, and preparedness for new health threats.
The CDC seeks to accomplish its mission by working with partners throughout the nation and the world to:
• monitor health,
• detect and investigate health problems,
• conduct research to enhance prevention, develop and advocate sound public health policies,
• implement prevention strategies,
• promote healthy behaviors,
• foster safe and healthful environments, provide leadership and training.

Question 2

Gloves

Answer 2

Question 3

Categories of Disinfecting / Sterilizing
Chemicals

Answer 3

Question 4

Dental Unit Waterlines (DUWLs), Biofilm and Water Quality

Answer 4

1. Discharge air and water for 20-30 seconds after each client, from any dental device connected to the dental water system that enters clients mouth. (handpieces, cavitron, air/water syringe)
2. Flush dental waterlines and faucets for 1-5 minutes before using for client care.
   *
3. Disinfect dental unit waterlines (DUWLs).
   *Reminder: this is CDC; we do 2 mins!

Question 5

Infectious Disease

Answer 5

• Infectious disease: occurs when a microorganism in the body multiplies and causes damage to the tissue

Question 6

Pathogens

Answer 6

Micro organisms that cause infectious diseases

Question 7

Opportunistic Pathogens

Answer 7

When normal microorganisms have favourable conditions for them to become harmful

Question 8

Endogenous diseases

Answer 8

Are caused by microorganisms in or in the body

Question 9

Exogenous disease

Answer 9

Caused by microorganisms not normally present on or in the body
Contaminated from outside

Question 10

Toxigenic disease

Answer 10

Eating contaminated food
When microorganisms come from exogenous, then infect body

Question 11

Bacteriophage

Answer 11

Viruses that infect bacteria
1915-1922

Question 12

Prion

Answer 12

Infection agent composed of protein
Causes degenerative brain disease
In humans called Creutzfeldt-Jacob
Prions are not microorganisms
Always Fatal
In animal- mad cow

Question 13

Asepsis is

Answer 13

Cleaning and disinfecting

Question 14

Standards precautions

Answer 14

Standard Precautions
Are a set of infection control practices used to prevent the transmission of diseases through the contact with:
1. blood
2. all body fluids, secretions, and excretions (except sweat) regardless of whether they contain blood
3. nonintact skin
4. mucous membranes.

Question 15

Modes of Disease Transmission
Direct Contact

Answer 15

1. Direct Contact: Contact with microorganisms at the source as in the clients mouth. Touching soft tissue or teeth.
   Can penetrate the body through small breaks or cuts in the skin, fingernails of ungloved hands
   •Ex: Herpes infections of the fingers, STD’s, Skin diseases

Question 16

Modes of Disease Transmission
Indirect

Answer 16

2. Indirect Contact: Contact with items contaminated with a clients microorganisms such as:
   > surfaces, hands, contaminated sharps, contaminated instruments, equipment.
   > carry a variety of pathogens through blood, saliva, other secretions from previous client
   • Hep B and C viruses
   • Ex: Needlesticks
   •Skin infection and common cold are spread by this mode

Question 17

Modes of Disease Transmission
Droplet Infection

Answer 17

3. Droplet Infection: Contact with sprays, splashes, aerosols or splatter containing microorganisms. E.g use of cavitron
   •Transmitted through close contact
   •Enter through unprotected skin, eyes, nose, mouth.
   •Masks, eyeglasses, face shields
   •Influenza, mumps, rubella, herpes virus

Question 18

Modes of Disease
Transmission
Airborne Infection

Answer 18

4. Airborne Infection: smaller particles, can remain airborne for hours, can be inhaled
   •Tuberculosis, chickenpox, measles
   •Surgical masks are not designed to protect
   •N-95 respirator

Question 19

Chain of Infection

Answer 19

Question 20

Routes of Entry Into the Body

Answer 20

Question 21

Sterilization:

Answer 21

• process intended to destroy/kill all mo’s in a material or on an object
• highest level that can be achieved.
• Destroys spores which are the most difficult to destroy.

Question 22

Disinfection:

Answer 22

• process that destroys mo’s, NOT spores & viruses OR
• decreases/minimizes amount of pathogenic organisms on objects or in materials so that they pose no threat of disease.

Question 23

Bactericides

Answer 23

Kills Bacteria

Question 24

Bacteriostatic

Answer 24

Stop of Growth does not kill

Question 25

Pasteurization

Answer 25

Reduce bacteria and destroy pathogens. (Milk)

Question 26

Lyophilization

Answer 26

Preserving microbes by removing water, then rapidly freeze, dry using vacuum pump

Question 27

SPORES

Answer 27

• One of the resistant forms of life against heat, drying, and chemicals • Bacteria that develop a defense mechanism against death • Biologic monitors: spores of Geobacillus stearothermophilus, and Bacillus atrophaeus used to monitor use and function of heat and gas sterilizers

Question 28

Sterilization

Answer 28

• The three common types of sterilization used in dentistry are: 1. Heat Sterilization 2. Gas Sterilization 3. Liquid Chemical Sterilization

Question 29

Heat Sterilization

Answer 29

• Steam, dry heat, and unsaturated chemical vapour • Heat sterilizers 121C-190.6C and monitored using bacterial spores (biological monitoring) • Effective

Question 30

Gas Sterilization

Answer 30

Ethylene oxide gas sterilizers- not commonly used Long exposure time High cost of gas sterilizers Special handling of ethylene oxide gas sterilant

Question 31

Liquid Chemical Sterilization

Answer 31

Room temp Used on items that can be damaged by heat sterilization Glutaraldehyde, special hydrogen perovide, Glutaraldehyde-phenate No spore tests, difficult to monitor Estimate chemical concentration of active sterilant

Question 32

Disinfecting ingredients

Answer 32

Question 33

Factors Influencing Microbial Growth

Answer 33

1. Temperature 2. Atmospheric Pressure 3. pH 4. Salinity 5. Osmotic Pressure 6. Hydrostatic Pressure 7. Radiation

Question 34

Factors Affecting Microbial Growth

Answer 34

1. MESOPHILES Optimal growth is at body temperature (37°C). Eg. human body. о Can grow @ temperatures ranging from 22-45°C Bacteria in human body, including those causing infectious diseases such as: • caries, • periodontal disease, • tuberculosis, • bacterial pneumonia, • tetanus.

Question 35

Factors Affecting Microbial Growth

Answer 35

2. THERMOPHILES • heat-loving bacteria. • range of 45-70°C. (Ideal temp. for growth is 56°C) • Eg. Compost, "geyser" hot water

Question 36

Factors Affecting Microbial Growth

Answer 36

3. PSYCHROPHILES • cold-loving bacteria. • Temperature ranges from 1-22°C, (Ideal temp. for growth is 7°C) • Eg. Refrigerator, ocean bacteria, principal cause of spoilage of refrigerated food

Question 37

Atmospheric Pressure (oxygen metabolism)

Answer 37

• Many microorganisms require molecular oxygen to carry on metabolic activities. • Microorganisms can also be classified according to the requirement for oxygen: 1. Obligate Aerobes- grow only in presence of oxygen (20% concentration). 2. Obligate Anaerobes- grow only in absence of oxygen 3. Facultative Anaerobes- grow in the presence or absence of oxygen - in absence of oxygen they undergo anaerobic respiration or fermentation & produce less ATP=less growth 4. Microaerophiles- can tolerate only low conc. of oxygen (4%) 99% of the bacteria in the mouth are obligate anaerobes or facultative anacrobes

Question 38

PH levels

Answer 38

Question 39

Acidogenic

Answer 39

Bacteria produce acid during growth

Question 40

Aciduric

Answer 40

Bacteria that survive and grow in an acidic environment Contribute to dental caries

Question 41

Salinity Halophilic Bacteria

Answer 41

NACL loving Bacteria • Halophiles : Halophiles are organisms that thrive in high salt concentrations. They are a type of extremophile organisms.

Question 42

Salinity Haloduric Bacteria

Answer 42

2. Haloduric Bacteria- capable of existing(do not prefer) in a medium containing a high concentration of salt(sodium chloride) Example: Staphylococcus aureus

Question 43

Osmotic Pressure Osmotolerant

Answer 43

• Osmotolerant : Osmotolerant bacteria are those bacteria that can tolerate high osmolarity. Osmolarity is established when there are solutions of different concentrations on either sides of a semipermeable membrane.

Question 44

Osmotic Pressure Saccharophiles

Answer 44

Question 45

Hydrostatic Pressure (pressure exerted by a fluid)

Answer 45

Barotolerant-survive in varying pressure environment; adaptable barophile, also sometimes called a piezophile, is 1 organism which thrives at high pressures, such as eep sea bacteria or archaea.

Question 46

History of Antimicrobials

Answer 46

• Paul Ehrlich (1854-1915) was the first person to use chemotherapeutic drug or antimicrobials to treat a bacteria infection. • He used sulfonamides to treat the disease syphilis. • Alexander Fleming (1881-1955) discovered a "Penicillium" mold producing a substance he called "Pericillin" that killed staphylococci bacteria.

Question 47

How Do Antimicrobials Work?

Answer 47

• Interfere with growth and replication of microbes. • Inhibit the metabolic machinery of the host cell to replicate. • Cause damage to the host cells.

Question 48

Antibiotics

Answer 48

• Discovery of antibiotics occurred in the 1950's • Antibiotics are one type of antimicrobial and act on a bacterial cell (prokaryotic cell). • Antibiotics do not impact or harm eukaryotic cells or viruses.

Question 49

Sulfonamide

Answer 49

• Antimicrobial agents • Bacteriostatic and inhibit growth and multiplication of bacteria, but do not kill them.