Microbiology

MICROBIOLOGY NOTES

Aseptic Technique

• Procedures to prevent bacterial growth

1. Used for surgery
2. Used for microbiology lab

• Wash & use disinfectant/antiseptic on any surface
• Wash hands & don't touch surfaces directly
• Use clamshell method to open/access petri dishes
• Do not breathe on specimen (wear masks)

Basic Streak-plating

• There are several methods for isolating colonies of bacteria on the agar
• Obtain speciman on cotton swab
• Gently rub swab over surface of the agar in the desired area
• Be sure not to penetrate the surface but also to touch the surface

Measuring Susceptibility

• Divide & label the sections of the plate according to the independent variables
• Evenly spread bacteria on entire plate

Zone of Inhibition (the place where bacterial growth was prevented)

• Place disk containing anti-microbial agent on agar in specific locations
• Measure the diameter of the area where bacterial does not grow

Disinfectants

• Destroy microorganisms found on nonliving area
• Bleach, lysol, lime away

Antiseptics

• Kills inhibits on living surfaces
• Lysterine, hydrogen peroxide

Antibiotics

• Kill inside living things
• Inhibits their growth; changes cell membrane

Bactericidal

• Penicillan
• Ampicillan

Bacteristatic (doesn't kill, just stops growth)

• Erythromycin
• Streptomycin
• Rifampin

Identifying Bacteria

• Colonies

1. Usually differ in shape, color, & shininess
2. Composed of thousands of cells
3. Can be seen with the naked eye