Mcrobiology

What type of bacteria is this?

Spirillum

What type of bacteria is this?

Coccus

What type of bacteria is this?

Bacillus

What type of **attached** cell is this?

**Dipto-:** Cells arranged in pairs

What type of **attached** cell is this?

**Strepto-** : cells in attached in chains

What type of **attached** cell is this?

**Tetrads:** Cells arranged in squares

What type of **attached** cell is this?

Random planes of clumped cells + planes

Describe the features of **Gram Positive Bacteria**

• Thick layer of peptidoglycan

• This holds on to the dye crystal violet

• Dye is washed out by ethanol

• They appear purple

Give an example of a **gram positive**

Stapyloccus

**T/F:** Penicillin is effective against **Gram Positive Bacteria**

**True**

Describe **Gram Negative Bacteria**

• They have a complex cell wall w/ a thin layer of peptidoglycan

• They also have a thick outer layer of lipopolysaccharide

• Crystal Violet is removed when rinsed with ethanol

• They appear pink

Give an example of **Gram Negative Bacteria**

E.Coli

**T/F: Penicillin is not effective against Gram Negative Bacteria**

**True:** Penicillin is not effective against GNB so Vanomycin is used instead

Described the process of **A Gram Stain**

• Begin with a heat-fixed emulsion

• Cover the smear with crystal violet stain for 1 minute

• Grasp the slide with a slide holder + rinse w/ distilled water

• Cover the smear w/ iodine stain for 1 minute

• Rinse w/ distilled water

• Decolorise with 95% ethanol until the run-off is clear

• Counterstain with safrinin

• Gentle blot dry in bibulous paper