Controlling Microbial Growth in Vitro

Question 1

What is the pathogenic staphylococcal species?

Answer 1

staphylococcal aureus

Question 2

What microbes are obligate intracellular pathogens?

Answer 2

Viruses

Question 3

Sterilization

Answer 3

Removal of all microorganisms (absolutely free of microbes, endospores and viruses).

Question 4

Disinfection

Answer 4

Eliminates most pathogens (not endospores)

Some viable microbes may exist.

Question 5

What disinfectants is used on inanimate objects and surfaces?

Answer 5

Disinfectant or biocides or germicides

Question 6

What disinfectant is used on living tissues (skin)?

Answer 6

Antiseptics (de-germining)

Question 7

Pasteurization

Answer 7

Brief heat treatment used to reduce organisms that cause food spoilage.

Question 8

True or False:

Surfaces can also be pasteurized?

Answer 8

True

Question 9

Sanitized

Answer 9

Reducing microbial contamination to acceptable “safe” levels.

Question 10

Preservation

Answer 10

Process used to delay spoilage of perishable items.

Question 11

What control approach often includes that addition of growth inhibiting ingredients?

Answer 11

Preservation

Question 12

What do the sufix -cide or dical refer to?

Answer 12

Killing

Question 13

What are chemicals that kill microbes?

Answer 13

Germicidal agents, biocidal agents and microbicidal agents.

Question 14

What agents kill bacteria, but not necessarily endospores?

Answer 14

Bactericidal agents

Question 15

What do sporicidal agents kill?

Answer 15

Bacterial Endospores

Question 16

What agents kill fungi and fungal spores?

Answer 16

Fungicidal agents

Question 17

What do algicidal agent and viricidal agents?

Answer 17

Algicidal - kill algae

Viricidal - destroy viruses

Question 18

What is growth?

Answer 18

The acquisition of biomass leading to cell division, or reproduction.

Question 19

Tolerance means?

Answer 19

Microbes will survive under certain conditions, but will not necessarily grow.

Question 20

-phile means

Answer 20

Describe conditions permitting growth.

Question 21

What the difference between thermophilic bacterium and thermotolerant?

Answer 21

Thermophilic will grow under conditions of elevated temperature. Thermotolerant bacterium will survives, but will not necessarily grow.

Question 22

What is the difference between obligate and facultative?

Answer 22

Obligate - means that a given condition is required for growth.
Facultative means the organisms can grow under conditions, but is not required.

Question 23

What factors can affect microbial growth?

Answer 23

Nutrients, moisture, temperature, pH, Osmotic pressure and salinity, barometric pressure.

Question 24

What means that the microbes prefer pH of 2-5?

Answer 24

Acidophiles (ex. Helicobacter pylori)

Question 25

What means that the microbes prefer pH greater than 8.5?

Answer 25

Alkaliphiles (ex. yeast, vibrio cholerae)

Question 26

What are Halophilies?

Answer 26

Microbes that prefer a certain osmotic pressure and salinity. (ex. staphylococcus aureus)

Question 27

What microbes prefer barometric pressure?

Answer 27

Barophiles

Question 28

What is pickling?

Answer 28

Pickling is in a hypertonic. The bacteria undergo plasmolysis which prevents food spoilage.

Question 29

What types of microbes are obligate aerobes?

Answer 29

Most fungi, algae, protazoa, and bacteria

Question 30

Are facultative aerobes gram positive or negative pathogens?

Answer 30

Gram negative pathogens (ex. escherichia)

Question 31

What amount of oxygen do microaerophiles require?

Answer 31

Roughly 5% of oxygen

Question 32

What microbes are killed by the presence of oxygen?

Answer 32

Obligate anaerobes (ex. clostridia)

Question 33

Aerotolerent

Answer 33

Can live in oxygen environments, just won't necessarily grow.

Question 34

What are capnophiles?

Answer 34

Grow in environments with higher concentration of CO2.

Question 35

Where are most canophiles found in the body?

Answer 35

Most are found in the intestinal tract, respiratory tract, and other body tissues where pathogenic bacteria grow.

Question 36

What does an anoxic jar do?

Answer 36

An anoxic jar creates an oxygen free atmosphere for anaerobe growth.

Question 37

What is the O2 free chamber used for?

Answer 37

The anaerobic chamber is for building up for culturing bacteria.

Question 38

Is bacterial growth an increase in number or size?

Answer 38

Number

Question 39

How do bacteria divide?

Answer 39

Binary fission

Question 40

What is generation time?

Answer 40

The time is takes one cell to be come two cells. (ex. E.coli = 20 minutes)

Question 41

What are artificial media?

Answer 41

Liquid and solid (physical state) Chemical defined, complex media (composition) Selective media, differential media, enriched media, aerobic media (function)

Question 42

Define: Chemically defined

Answer 42

Highly purified inorganic and organic compounds in H2O

Question 43

What is complex (undefined) microbial growth?

Answer 43

digests of casein, beef, soybeans, yeast

Question 44

What are the three types of media? And what does each mean?

Answer 44

Selective - suppress unwanted microbes Differential - differentiation of colonies Enriched - similar to selective but increase desired microbes levels

Question 45

Are the three types of media (selective, differential, and enriched) exclusive?

Answer 45

No, they are not exclusive. Blood agar, for example, is both enriched and differential.

Question 46

What is MacConkey agar used for?

Answer 46

Inhibit gram (+), lactose, pH indicatior (pink = acid) Lactose fermenter pink colonies (Ex. E. coli) Non-lactose fermenter white/transparent (salomnella)

Question 47

What is Mannitol-salt agar is used for?

Answer 47

For staphylococus | It inhibits most bacteria. Yellow = acid

Question 48

What indicates staphylococus aureus?

Answer 48

Yellow colonies

Question 49

Does staphylococus epidermidis have any color?

Answer 49

No

Question 50

What do metallic green sheen colonies on a eosin methylene blue agar indicate?

Answer 50

Strong lactose fermenter. Also, can indicate E. coli.

Question 51

What does brown-pink coloration of growth on a eosin methylene blue agar indicate?

Answer 51

Weak fermentation of lactose. Also can indicate klebsiella or enterobacter.

Question 52

What does translucent color on a eosin methylene blue agar indicate?

Answer 52

Non-lactose. Also indicates pseudomonas or salmonella (non-coliform)

Question 53

What kind of enterobacteriaceae are found when a patient has E. coli?

Answer 53

EHEC-0157:H7 ex. of symptoms = bloody diarrhea

Question 54

How do you culture Protoza?

Answer 54

Protozoa can be cultured in vitro.

Question 55

What are the four main phases of growth in bacterial culture?

Answer 55

Lag phase, exponential growth, stationary, and death phase.

Question 56

When brewing beer, which phase of the four main phases would you need to have the beer in?

Answer 56

The exponential growth phase. This is done by continuously adding more of the food or liquid to the growth chamber.

Question 57

What are contaminants?

Answer 57

Unwanted organisms

Question 58

What is the cloudiness or haziness of a fluid caused by large numbers of individual particles in the test tubes called?

Answer 58

Turbidity

Question 59

What is direct cell count?

Answer 59

When special slides are used to count how many living cells are in a mL.

Question 60

What is a flow cytometer used for?

Answer 60

It is a technology that is used to analyse the physical and chemical characteristics of particles in a fluid as it passes through at least one laser.

Question 61

What is a laboratory technique of molecular biology based on the polymerase chain reactions?

Answer 61

Real-time PCR

Question 62

What types of plates are used for indicating streptococcus species?

Answer 62

Blood agar plates

Question 63

What are the three branches of streptococcus?

Answer 63

alpha-hemolytic, beta-hemolytic, and gamma-hemolytic.

Question 64

What can alpha-hemolytic cause?

Answer 64

Pneumoniae and viridans

Question 65

What can beta-hemolytic cause?

Answer 65

Pyogenes (group A strep) and agalactiae (group B strep).

Question 66

Which type of streptococcus causes strep throat?

Answer 66

Streptococcus pyogenes group A bacteria.

Question 67

What can gamma-hemolytic cause?

Answer 67

Entreococcus

Question 68

Which type of strep reacts with bacitracin disks?

Answer 68

Group A

Question 69

What are chocolate agar plates used for?

Answer 69

Growth of fastidious organisms. (ex. neisseria gonorrhoeae and neisseria meningitis)

Question 70

What is a drug or chemical that inhibits growth?

Answer 70

Microbistatic agents

Question 71

What agent is one that specifically inhibits the metabolism and reproduction of bacteria?

Answer 71

Bacteriostatic agent

Question 72

What is the process that combines dehydration and freezing. Typically used to preserve foods, make antibiotics, microorganisms and other biological materials?

Answer 72

Lyophilization

Question 73

What is the term used to refer to the presence of pathogens in the blood and tissue?

Answer 73

Sepsis

Question 74

What does asepsis mean?

Answer 74

The absence of pathogens.

Question 75

What do antimicrobial procedures depend on?

Answer 75

Type of microbe, extent of contamination, environment, and composition of infected tissue.

Question 76

Which bacteria is resistant to heat, drying, and numerous chemicals?

Answer 76

Bacterial endospore

Question 77

What bacteria's resistance is dependent on the cell wall structure?

Answer 77

Mycobacterium species

Question 78

What microbes generally excrete in feces and cause diarrheal disease?

Answer 78

Protozoan cysts and oocysts

Question 79

What species can grow in the presence of many chemical disinfectants?

Answer 79

Pseudomonas species

Question 80

Which viruses lack envelopes and are more resistant to chemical killing?

Answer 80

Naked viruses

Question 81

What temperature destroys most microoganisms and viruses?

Answer 81

Boiling

Question 82

Is boiling a good means of sterilization?

Answer 82

No

Question 83

True or False: | Boiling destroys endospores

Answer 83

False

Question 84

What does pasteurization do?

Answer 84

Pasteurization reduces organisms, but does not sterilize. It also increases shelf life of food.

Question 85

What does an autoclave do?

Answer 85

An autoclave uses pressurized steam to sterilize.

Question 86

What are the requirements to sterilize prions in an autoclave?

Answer 86

132*C and 15 psi for 4.5 hours

Question 87

Do cold temperatures kill microorganisms?

Answer 87

No, generally the microorganisms won't die. Instead, their metabolic activities are slowed down.

Question 88

What is desiccation?

Answer 88

When microoganisms are dried. They are still viable, but cannot reproduce.

Question 89

True or False: | Radiation (gamma rays) can be used to destroy microbes in air, drinking water, and surfaces?

Answer 89

True

Question 90

What are ultrasonic waves used in hospitals and medical and dental clinics for?

Answer 90

Sterilization of equipment

Question 91

How do you separate cells/microorganisms from liquids or gases?

Answer 91

Filtraton

Question 92

True or False: | Gaseous atmospheres can be altered to inhibit growth?

Answer 92

True

Question 93

True or False: | Chemicals used to disinfect and sterilize are called germicidal chemicals?

Answer 93

True

Question 94

True or False: | Strong organic acids are often used as food preservatives?

Answer 94

False, weak ones are

Question 95

True of False: | Nitrates and nitrites are used in processed meats?

Answer 95

True; they are used to inhibit germination of endospores and growth of vegetative cells.

Question 96

What are lipid-containing viruses (category A)?

Answer 96

Lipoviruses

Question 97

True or False: | Category B viruses contain lipid in the virus?

Answer 97

False; they do not contain them