Bacteria (and other small topics)

The Good, The Bad, and The Ugly

Arrangement Groups

• Chains: strepto-• Pairs: diplo-• Irregular clusters:staphylo-• Foursomes: tetrad• Cubes: sarcina

Shape Groups

• Spheres – coccus (cocci)• Rods – bacillus (bacilli)• Spirals, bent rods, and corkscrews

– spirillum (spirillae)

Gram Stain Reaction

• Pink/red – Gram negative• Blue/purple – Gram positive• Mixture – Gram variable• See Gram Stain Procedure on next

slide

Fix the bacteria. Bathe with Crystal Violet for 1 minute. Rinse with water. Bathe with Gram’s Iodine for 1 minute. Rinse with water. Rinse with drops of ethanol until runoff is clear. Bathe with Safranin for 1 minute. Rinse with water. Flame dry. View, sketch and describe.

1. What is this?

1. What is this?

Gram negative diplococci

2. And this?

2. And this?

Gram positive bacillus

3. And these are…..

3. And these are…..

Gram negative spirillae

4. How about these?

4. How about these?

Gram positive streptobacilli

5. These are……..

5. These are……..

Gram positive spirillae

6. What are these?

They’re actually Gram positive staphylococci

7. What would you call these?

7. What would you call these?

Gram positive streptococci

8. And finally, these are…..

8. And finally, these are…..

Gram positive sarcina (cocci)

So how did you do?

5 out of 8 would be acceptable.