Archaea: Include prokaryotes that do not have peptidoglycan in their cell walls.

Live in extreme environments.

Bacteria: Includes all the pathogenic prokaryotes & nonpathogenic prokaryotes found in soil & water. Also included are photoautotrophic prokaryotes.

Features of Archaea a-d:

a). Methanogens

b). Hyperthermophiles

(pyrodictium)

c). Acidophiles

(sulfolobus)

• Includes 5 phylum
• Largest taxonomic group of bacteria
• gram-negative
• chemoheterotrophic: feeds on other/absorbs chemicals for nutrients

• Can grow in very low nutrient levels
• Includes nitrogen-fixing bacteria
• 2 Genera

1. Rickettsia
2. Rhizobium

• Species - Rickettsia recketsii
• Obligate Intracellular Parasite: must live in the cell of another organism.
• Rocky Mountain Spotted Fever caused by R. rickettsii

• agricultural bacteria that infect the roots of legume plants.
• Symbiotic relationship with legumes
• Nitrogen fixation - Bacteria takes nitrogen from atmosphere and converts it into ammonia/protein, which can be taken up by plants from soil

• 3 genera

1. Bordetella
2. Neisseria
3. Thiobacillus

• Present in the mucus of animals (humans)
• Neisseria gohorrhoeae causes gonorrhoea & meningitis
• Opportunistic pathogen  

Ex. Stress

• Bordatella pertussis causes whooping cough or pertussis

Thiobacillus

(Thio = Sulfur)

• Not a pathogen
• Chemoautotrophs
• Common soil inhabitant
• sulfur-oxidizing bacteria (mining operations - leach metals from rocks)

• Includes the enterics (biggest group of pathogens for humans.
• Largest subgroup of proteobacteria
• Includes 6 genera.

• Giant bacterium - 750 microns
• sulfur pearl of nambia

• Francisella Tularensis causes tularemia.

Order - Legionellales

Genera -Legionella

• Causes legionnaires disease (pneumonia in the lungs due to breathing in bacteria contained in water droplets of spas, hot tubes etc.)
• Species - Legionella pneumophila

Order - Pseudomonadales

Genera - Azobacter

• Free Living (non-symbiotic)
• Nitrogen Fixing Bacteria

Order - Vibrionales

Genera - Vibrio

• Vibrio cholerae is the cause of cholera.
• Curved rods.

Order - Pseudomonadales

Genus - Pseudomonas

• Very common bacteria found in soil.

• Inhabit the mucous membranes of the upper respiratory tract, mouth, vagina & intestinal tract.
• Haemophilus influenzae cause meningitis in young children & ear aches.

Order - Enterobacteriales 

(enterics)

• Includes 8 genera
• Common in the human intestines.

• Most familiar organism in microbiology.
• Species - Escherichia coli

• Species - Samonella enterica

• Shigella can cause dysentery

• Commonly found in soil & water.
• Species - Klebsiella pneumoniae causes pneumonia.

• Species Serratia marcescens cause urinary & respiratory tract infection.
• bacteria commonly found on hospital equipment.

• Called a swarmer cell
• Concentric rings on streak plates

• Species - Yersinia pestis causes plague, the black death of medieval Europe.

• Species - Enterobacter cloacae & Enterobacter aerogenes causes urinary tract infections and hospital acquired infections.

• Includes predatory bacteria
• 3 genera

• Attack gram-negative bacteria.
• Host cell lysis.

• Sulfur-reducing bacteria

• Thin gram-negative rods, helical or vibrioid.
• 2 genera

• gastrointestinal pathogen
• Species - C. jejuni

• Species - Heliobacter pylori cause of peptic ulcers and stomach cancer.

• Gram - Negative bacteria

• Oxygenic - generate oxygen
• Conduct photosythesis
• Some free living, nitrogen fixers
• Bacteria: 1. Anabaena 2. Gloeocapsa 3. Nostoc 4. Oscillatoria 5. Spirulina (A Giant Never Orders Shrimp)

• Cyanobacteria evolved 2.2 billion yrs ago.
• Caused increase in oxygen to the atmosphere resulting in photosynthesis.
• Endosymbiosis  Theory (one organism[smaller] lives within another[larger])

• Are Anoxygenic - Do Not produce oxygen.

• Carry out photosynthesis
• Are anaerobic
• Habitat is in deep sediments of lakes and ponds.
• Bacteria is anoxygenic - Do Not produce oxygen.

• Low Guanine & Cytosine in DNA; Gram-Positive Bacteria(Bacteria that retain the crystal violet color after decolorizing by alcohol; they stain purple.)
• 7 Genera

• Common soil bacteria.
• Endospore-producing rods
• Species - Bacillus anthracis cause  anthrax, a disease of cattle, sheep and horses.
• white-ish and common contaminant in streak plates.

• Rod shaped cells contain endospores that are resistant to heat & chemicals.
• Obligate anaerobes.
• 3 pathogens are:

1. Clostridium tetani - cause tetanis
2. Clostridium botulinum-causes botulism
3. Clostrium perfringens  

• includes Staphylococcus aureus (impetigo)
• aureus = yellow 
• Facultative anaerobes
• Stahylo - cluster
• coccus = spherical in shape
• MRSA

• Grows  in the human intestine, vagina, mouth
• used to ferment foods (sauerkraut, pickles, buttermilk & yogurt

• includes many human pathogens
• Strepto = chains
• Many have enzymes that destroy host cells and tissues
• Includes Streptococcus pyogenes (beta-hemolytic streptococci)& S. pneumoniae (alpha-hemolytic streptococci)
• Necrotizing Fasciitis-releasing toxins that destroy tissue.

• Leading cause of nosocomial infections; resistant to antibiotics. 

• very small (can pass through bacteria filters.
• Lacks a cells wall
• includes Mycoplasma pneumoniae
• pleomorphic - different shapes

• High Guanine-cytosine base pairs in DNA & Gram positive bacteria
• Many are pleomorphic
• 5 genera

• Acid fast (mycolic acid)- mycolic acid in cell walls which is a waxy substance & prevents drying out. Not decolorized by acid alcohol.
• exhibit filamentous growth
• Mycobacterium tuberculosis - causes tuberculosis
• Mycobacterium leprae - causes leprosy

• Commonly isolated from soil
• produce most of our common antibiotics
• aerobes

• Facultative anaerobes
• Found in mouth & throat of humans/animals
• Filamentous (fungus like)

• Coryne = club shaped
• pleomorphic
• C. diphtheriae cause diphtheria

• Aerobic
• Acid fast(mycolic acid)- mycolic acid in cell walls which is a waxy substance & prevents drying out. Not decolorized by acid alcohol.

• 2 genera
• Cell walls do not contain peptidoglycan

• Gram negative coccoid bacteria
• C. trachomatis - causes blindness in less developed countries.

• C. psittaci causes the respiratory disease psittacosis.
• C. pneumoniae causes a mild form of pneumonia in adults. 

• Have axial filaments (endoflagella), making them rotate like corkscrews.
• Includes 3 genera

Borrelia causes lyme disease.

Leptospirosis is a disease usually spread to humans by water contamination.