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Flashcards in BacT Lec 2 Deck (68):
1

What are some extracellular bacterial structures?

Flagella
endoflagella/axial filament
Pili/fimbriae
Capsule
Biofilm

2

What are some intracellular bacterial structures?

Nuclear material
Ribosomes
Inclusion granules
Endospores

3

Flagella

*Locomotion/Motility
*Number and arrangement can be used for identification
Long, thin structures that extend outward from the surface of the envelope

4

Monotrichous Flagella

only one flagellum extending from one end of the bacterium

5

Many flagella extending from one end of the bacterium

Lophotrichous Flagella

6

Amphitrichous Flagella

One flagellum extending from each of the bacterium

7

Flagella extending from many different sites on the bacterium

Peritrichous Flagella

8

Endoflagella/axial filaments

Present in periplasmic space (*inside the bacteria) of spirochettes

9

*Name two bacteria that move with the use of Endoflagella/axial filaments.

*Treponema pallidum
*Leptospira

10

Pili/fimbria

Small thread like structures that facilitate *adherence to the host and *contribute to antigenicity. Also use to *attach bacteria to maintain themselves in a favorable environment.

11

Give an example of bacteria with Pili/fimbria

Bordetella bronchiseptica

12

*What is conjugation?

Through *sex pili that allow one bacterial cell adhere to another and exchange genetic material.

13

*What may cause pili loss?

*Mutation in disease-causing bacteria.

14

*Will pili reestablish if lost?

*Nope

15

Capsule (thick glycocalix) Polysaccharide (Not present in all bacteria)

Protect against phagocytosis
*protect form drying out
help adhere to a surface where conditions are favorable for growth

16

Name a bacteria with a capsule.

Bacillus anthracis - Discovered by Sir John McFadyean

17

Biofilm

Microbes come together in masses cling to surfaces, produces extracellular substances and take in nutrients and biofilm
Mech used to increase virulence

18

Give an example of a biofilm

Dental Plaque

19

*Nucleoid

Nuclear region is a mass of DNA; well defined although it is not surrounded by membrane.

20

*Plasmids

Smaller circular DNA molecules

21

Ribosomes

Site of protein synthesis. 70S ribosomes composed of *50S and *30S subunits

22

Inclusion granules

Stores nutrients for times of nutrient shortage.

23

Endospores

A dormant form that is produced when essential nutrients are depleted in certain bacteria

24

*What protects the endospore form damage?

*Organic acid called Dipicolinic acid

25

Name two examples of bacteria that develop endospores?

Clostridium tetani, Bacillus anthracis

26

What type of bacteria develop endospores?

Low G+C Gram-Postive

27

*How do bacteria reproduce?

*Binary fission

28

The time required for the number of bacteria in a culture to double is called?

*generation time (G)

29

Two common methods of measuring bacterial mass in liquid cultures.

Tubidity
Colony counting

30

*Tubidity

A measure of total bacteria (live and dead)

31

*Colony Counting

The number of viable bacteria in a culture

32

Three requirements for bacterial growth.

Sources of energy "organic" carbon
Metal ions
Optimal temp, pH and need or lack of need for oxygen

33

Three forms of bacterial metabolism.

Aerobic Respiration - Molecular Oxygen
Anaerobic Respiration - No Molecular Oxygen
Fermentation - Anaerobic or Aerobic - Facultative anaerobic bacteria

34

4 environmental factors influencing bacterial growth

Temperature
Hydrogen ion
Water activity
Atmosphere

35

Methods used to limit microbial growth

Refrigeration
Freezing
Boiling
Pasteurization
Acidification
Increase osmotic pressure
Oxygen removal
Drying
Gamma irradiation
Hydrostatic pressure
Chemical additives

36

Sterilization Methods

Moist heat
Dry heat
Incineration
Alcohol flame
Gamma irradiation
UV light
Membrane filtration
Cemical

37

Types of culture media (non selective)

Liquid (broth)
Solid (Agar Media)
Trypticase soy agar with blood

38

Selective media culture types

Phenylethyl Alcohol Blood Agar
MacConkey Agar
Hektoen Enteric Agar

39

PEA culture media is for?

Gram-Positive

40

MacConkey Agar media is for?

Gram-Negative

41

Bacterial identification methods

Biochemical
Antigenic
Phage typing
Virulence typing
Whole-cell fatty acid analysis
Genetic analysis
Protein analysis
Enzyme isotyping

42

Matrix Assisted Laser Desorption Ionization-Time of Flight-Mass Spectrometry (MALDI-TOF)

Measure a unique molecular fingerprint of an organism. Specifically measures highly abundant proteins that are found in all microorganisms

43

What are the only bacteria that have the Endoflagella/axial filaments?

Gram-Negative

44

*What staining is used to detect capsule on bacteria

*Simple Polychrome Methylene Blue

45

Origin of cross contamination?

Biofilms

46

What is the structure of bacteria DNA?

Chromosome *Supercoiled

47

T:F Prokaryotic ribosomes are larger than eukaryotic ribosomes.

False
Prokaryotic ribosomes are smaller than eukaryotic ribosomes.

48

Bacteria in endospore form are considered?

Extraordinary Resistant: Because they are not readily killed by many antimicrobial treatments

49

*What are the three location of endospores?

*Center, terminal, sub-terminal

50

How can the locations of the endospores help?

Location of endospores is used for identification

51

*What gives endospores their resistant?

*Dipicolinic acid

52

*Pilli/Fimbriae's presence on a bacteria greatly increase?

*The bacteria's ability to attach to the host and cause disease.

53

What are some environmental stresses that would normally kill bacteria, but endosores can survive?

High Temp
High UV Irradiation
Desiccation
Chemical Damage
Enzymatic Destruction

54

T:F Bacteria endospores are a form of reproduction.

False
It is a survival technique

55

When do bacteria reproduce?

Under suitable conditions. Proper nutrients, temp, and atmosphere

56

Two daughter cells grow and divide at the same rate as parent cells is know as?

*Exponential or Logarithmic Growth Rate

57

Knowing a bacteria's generation time can help us?

Differentiate between bacteria

58

Plotting the log of turbidity or number of living cells versus time is referred to at?

The growth curve

59

What are the three phases of bacterial growth?

Lag Phase (adaptive)
Log Phase (exponential)
Stationary Phase

60

Draw the complete bacterial growth phase.

Refer to slide 26 of Lecture 2 BacT.

61

Which is more accurate turbidity or colony counting?

Colony Counting

62

How much growth is happening in the Lag Phase?

Very little

63

What is needed for the Log Phase to be successful?

All the nutrients required, as well as proper temperature, pH and etc.

64

Which growth phase is it when nutrients becomes depleted?

Stationary Phase

65

Oxygen required for growth

Aerobic, Microaerophilic (Req O2, High O2 is toxic), & Capnophilic (High CO2)

66

Oxygen not required or utilized for growth

Obligately Anaerobic (Death by normal atmospheric O2 concentration), Aerotolerant Anaerobe (Poor growth in O2)

67

Oxygen not required but can be utilized for growth

Facultative Anaerobe

68

Draw the Food Danger Zone Guidelines

Refer to slide 33 lecture 2 BacT