Bacteria: eubacteria and Archaea

What magnification of the light microscope are we able to observe bacteria?

1000x

How do bacterial genomes differ from eukarya?

• Circular chromosome

• Haploid

• Condensed through supercoiling

• Do not contain introns

Intron

Non-coding segment within a gene that is not expressed in the final RNA product. Spliced out to change the functionality of a protein

Gram-negative bacteria

• Do not retain their stain (stains pink)

• Inner cell membrane

• Thin peptidoglycan wall

• Outer membrane contains lipopolysaccharides

PAMP (pathogen-associated molecular patterns)

Formed of LPS and peptidoglycans to trigger inflammation and immune response

Mollicutes

Eubacteria that lack a cell wall

Gram-positive bacteria

• Retain their stain (stains violet)

• Thick peptidoglycan cell wall

• Cell wall contains lipoteichoic acid (LTA)

Infection

The successful colonization of the body by a microbe capable of causing damage to the body

Virulence

The ability of a microbe to cause disease

Virulence factor

A microbial product or strategy that contributes to the ability of the microbe to replicate and/or survive without its host. (typically found on cell surface or excreted)

Pathogenesis

The development of a disease and the chain of events leading to that disease.

India ink capsules

Virulence factor produced by bacteria, sole function is to prevent phagocytosis by white blood cells.

Flagella

Whip-like propellers found in bacteria to enhance motility. Considered a virulence factor

Pili

Hair-like appendage found on the cell surface of bacteria, helps cell surface “stick” to things. Considered a virulence factor

Qualities of archaea that differ from eubacteria

• Ether linked cell wall

• EF2 sensitive

• Chloramphenicol resistant

• Kanamycin resistant

• Anisomycin sensitive

• Rifampicin resistant

• Has introns

Qualities of eubacteria that differ from archaea

• Ester linked cell wall

• EF2 resistant

• Chloramphenicol sensitive

• Kanamycin sensitive

• Anisomycin resistant

• Rifampicin sensitive

• No introns