Microbiology

1
Microbiology

• Class Three
• February 7-9
• Culture Characteristics

2
Class schedule( Part One)

• Check results from week 2.
• Record results in templates.
• Organisms studied week 2
• S. marcescens
• B. subtilis
• M. luteus
• E. coli

3
Culture characteristics

• Use supplement and handout to observe the growth
  of the four organisms in the slant, deep, broth,
  and on the plate.
• Do the organisms look like one of the examples on
  your sheet?
• Try to record their appearance on your templates

4
Culture observations on the agar plate

• Color production( chromogenesis). An example of
  this is the pink color of Serratia
• Growth pattern and characteristics
• Amount of growth( scant or heavy)

5
Comparison of E. coli and Micrococcus luteus
6
Colony morphology
7
Colony morphology
8
Margin of the colonies
9
Elevation
10
Broth culture( refer to supplement)

• Cloudy
• Turbid( Flocculent)
• Sediment formation
• Pellicle formation

11
Slants

• Is there growth in the bottom ?
• Is there growth on the slant itself
• What are the growth characteristics on the slant?
• Key words
• Aerobic
• Anaerobic
• Facultative

12
Isolation of Pure culture

• Observe your dilution streak of your mixed
  culture
• On the bottom of your Petri dish circle colonies
  of two organisms
• Example
• ML/SM mixture circle yellow and pink cultures
• With your inoculating loop lift cells from
  circled colonies and streak on new plate or
  inoculate a slant per detailed instructions in
  class

13
Part One Completion of week 2 work

• When you have finished observing all of your
  cultures
• Place all tubes in rack in hazardous waste
• Place all plates in cans in hazardous waste
• Wipe down desk top

14
New work( supply table)

• Eight Organisms for Study/Table
• 8 Plates
• 8 Deeps( if available)
• 8 Slants
• 8 Broths

15
Preparation

• Label all tubes and plates carefully
• Assign each member of the group 2 organisms
• Transfer the organisms to the culture media using
  aseptic techniques used in weeks one and two

16
Organisms for study

• Gram negative organisms
• PA - Pseudomonas aeruginosa
• PV- Proteus vulgaris
• EC- Escherichia coli
• EA- Enterobacter aerogenes
• Gram Positive Organisms
• BS - Bacillus subtilis
• SA - Staphylococcus aureus
• SE - Staphylococcus epidermidis
• SS- Streptococcus salivarius

17
Review for Quiz One

• Aseptic techniques
• Culture transfer techniques
• Media
• Safety precautions
• Microscope identification