Microbial Growth (in Vitro)

Question 1

What are Halophilic MOs?

Answer 1

MOs that prefer salty environments

Question 2

What are Haloduric MOs?

Answer 2

MOs that don’t prefer salty environments (but can still grow)

Question 3

What happens to cells without cell wall in Hypotonic solution?

Answer 3

Hemolysis (lysis)

Question 4

What happens to cells without cell wall in Hypertonic solution?

Answer 4

Crenation

Question 5

What happens to cells with cell wall in Hypotonic solution?

Answer 5

Plasmoptysis

Question 6

What happens to cells with cell wall in Hypertonic solution?

Answer 6

Plasmolysis

Question 7

Which temperature classification do pathogenic MOs have?

Answer 7

Mesophiles (closest to humans)

Question 8

List the 6 classifications of temperature tolerance in bacteria:

Answer 8

(Hyper)Thermophiles
Mesophiles
Psychrophiles & Psychrotrophs
[Psychroduric]

Question 9

What is the optimum range of Thermophiles?

Answer 9

50-60

Question 10

What is the optimum range of Mesophiles?

Answer 10

20-40

Question 11

What is the full range of Psychrophiles ?

Answer 11

-5 ~ 30
Optimum is 10~20

Question 12

What are Alkaliphiles?

Answer 12

MOs that prefer a pH>8.5

Question 13

What is the only human pathogen that is classified as an alkaliphile?

Answer 13

Vibrio cholera (small intestine)

Question 14

What is an Acidiophile?

Answer 14

MO that prefer pH 2-5

Question 15

Preferable pH for pathogenic MOs?

Answer 15

Neutral/slightly alkaline

Question 16

What are Microaerophiles?

Answer 16

MOs Require O2 in sub-atmospheric conc (5%)

Question 17

What are Facultative anaerobes?

Answer 17

MOs that Doesn’t care about O2 conc

Question 18

What are Aerotolerant anaerobes?

Answer 18

MOs that prefer no O2 but tolerate it

Question 19

What is considered a high CO2 concentration?

Answer 19

5-10 %

Question 20

What does HBOT stand for?

Answer 20

Hyperbaric oxygen therapy

Question 21

What are piezophiles?

Answer 21

MOs that grow in high atmospheric pressure

Question 22

2 types of enriched medium agar

Answer 22

Blood agar
Chocolate agar

Question 23

State a type Enriched medium broth

Answer 23

Thioglycolate for anaerobic cultures (at the bottom)

Question 24

Give an example on a selective medium
+ state what it’s selective for
(+ What inhibitors are added)

Answer 24

MacConkey agar ; G- bacteria ; (Bile salts & Crystal violet)

Question 25

What is the incubation time forr mycobacterium TB?

Answer 25

4-6 weeks (slow grower)

Question 26

Usual incubation time for MOs?

Answer 26

24-28h

Question 27

3 types of incubators

Answer 27

Ordinary (room air) Anaerobic CO2 incubator

Question 28

2 life forms that survive desiccation

Answer 28

Bacterial spores Protozoan cysts

Question 29

Give 3 examples of cell cultures

Answer 29

Embryonated chicken eggs Lab animals Cell culture lines

Question 30

Give 3 examples of cell culture lines

Answer 30

Monkey kidney cells Human lung cells Cancer cells

Question 31

How is positive growth of obligate pathogens identified?

Answer 31

Cytopathogenic effects

Question 32

3 examples of obligate intracellular pathogens

Answer 32

Viruses Chlamydia Rickettsia

Question 33

Which agar has the lowest pH

Answer 33

Subouraud dextrose agar

Question 34

What agars can be used for fungi?

Answer 34

BHI & SDA

Question 35

What MOs kingdom are acidiophiles?

Answer 35

Fungi

Question 36

2 species of ameba & ameba-like protozoa that causes fatal CNS infection

Answer 36

Acanthamoeba Naeglaria

Question 37

Xenic vs axenic ?

Answer 37

Xenic contain foreign cell

Question 38

What is an example of a subject of a sporicidal?

Answer 38

Clostridium spores

Question 39

Aseptic vs antiseptic techniques

Answer 39

Aseptic: during procedure (sterile) Antiseptic: eliminating pathogen on a living surface (disinfection)

Question 40

Which 3 microbes are most resistant to sterilization?

Answer 40

Prions Coccidia Mycobacteria

Question 41

Which microbe is least resistant to sterilization?

Answer 41

Lipid / medium sized viruses

Question 42

Which 2 microbes have intermediate resistance to sterilization?

Answer 42

Non lipid / small viruses Fungi

Question 43

What is TDP?

Answer 43

Thermal death point (Lowest temp to sterilize a pure culture)

Question 44

What is TDT?

Answer 44

Thermal death time (Shortest time to sterilize a pure culture)

Question 45

What temperature do we use in dry heat sterilization?

Answer 45

160-165 for 2h Or 170-180 for 1h

Question 46

What are the requirements for autoclaving ?

Answer 46

121.5°C / 15psi / 20mins

Question 47

When is filtration used? Give examples

Answer 47

When heat is inappropriate (Fluids & Protein)

Question 48

Define bionurden

Answer 48

Type & quantity of microbe to be disinfected

Question 49

How is the power of disinfectants assessed ?

Answer 49

By comparison to phenol

Question 50

Mechanism of disinfection of phenols (alcohols)

Answer 50

Destruction of cell membrane ++ proteins & enzymes

Question 51

2 Examples of disinfectant that destroy cell membrane

Answer 51

Surface-active soaps & detergents

Question 52

4 Examples of disinfectant that destroy protein & enzymes

Answer 52

H2O2 Formaldehyde Halogens heavy metal salts

Question 53

7 examples of heavy metal salt disinfectants

Answer 53

Silver Nickel Mercury Zinc Copper [A silver nickel maycure a زنجي cop] Calomel & Mercurochrome

Question 54

What is calomel made from?

Answer 54

Mercury chloride (Hg2Cl2)

Question 55

What is mercurochrome made from?

Answer 55

Hydroxymercurifluorescein

Question 56

What disinfectant work on nucleic acids?

Answer 56

Ethylene oxide

Question 57

Which disinfectants are also sterilizing?

Answer 57

Formaldehyde & Ethylene oxide