Bacteria diversity

Page 1

3 domains

Eukaryotic

Bacteria

Archeae

Measuring diversity

House keeping genes

Whole genome sequence

Cyanobacteria

One of the most abundant

Responsible for O2 pressure in atmosphere

Photosynthetic

Form symbiotic relationships with other organisms -- i.e. lichen

Bacillus

Lost of diff habitats

Water

Soil

Extremophiles

Hot

Cold

Lots o salt

Involved in production of antibiotics

Produce spores in right conditions

Aerobic

Spores are heat resistant, antibiotic resistant

Serve to protect DNA for survival

gram positive

Pathogenetic bacillus spp

Bacillus anthracis

Spores

10-20 thousand spores inhaled -- move to lymph nodes, prod toxins

Often lethal as symptoms appear too late for effective treatment

Eaten-- move to lymph nodes then prod toxins

Cutaneous -- sores easy to treat

Bite and fly

Injection

Bioterrorism ?

Notifiable

Correct disposal

Decontamination

How it causes disease?

Capsule - on plasmid

Anthrax toxin - another plasmid

Protective antigen

Edema factor

Lethal factor

Vaccines available

Bacillus cereus

Spores ubiquitous in environment

Food poisoning

Emetic

Heat stable emetic toxin

Diarrhoeal

Non-haemolytic enterotoxin

Haemolytic enterotoxin

Bacillus thuringiensis

???

Stream

Biocontrol agent

GM crops

Parasires of bacteria

Vampirococcus

Attach

Bdellovibrio

Sit in periplasmic space

Daptobacter

Harpoon themselves

Bacteriophages

Lytic cycle

Lysogenic cycle

See previous lectures

Causes kidney failure and brain damage in young children

Symbiosis

Nitrogen fixing bacteria

Legumes

Lichens

Commensal bacteria

Neither harm nor help

May produce Vitamins

Colonisation inhibition

Opportunistic pathogens

Unculturables

<1% of bacteria are culturable

Culture independent techniques allows studies of other 99%

Metagenomics

All DNA from a particular community

Use PCR or shotgun sequencing

Cattle GI micro biome

Variation along gut

How microbes interact

GM ??

Bacterial communication

Quorum sensing

Way of seeing what other organisms nearby

Cross talk

Biofilms

Slime layer around colony of bacteria

Virulence

Applications

Antibiotic resistance??

Drugs to effect Quorum sensing ??

Communication with eukaryotes

Pseudomonas aeruginosa

2 different quorum sensing systems

??

Thermus aquaticus

Found in hot springs in yellowstone

Responsible for discovery of main enzyme in PCR

Endosymbiont theory

Human micro biome -

???

Of 200 million species of bacteria

about 2000 cause disease in humans in livestock

0.001%

Bacterial diversity