Transcript The Nonproteobacteria Gram

Gram Positive Bacteria
• Grouped based on C + G ratio (nitrogen bases
cytosine and guanine)
• Divided into 2 Phyla
– Firmicutes (low C + G )
– Actinobacteria (High C + G)
Firmicutes
• Low G + C ratio
• Includes endospore forming and wall-less bacteria
• Phylum: Firmicute
• 3 Classes:
– Clostridia
– Bacilli
– Mollicutes (mycoplasmas)
Clostridia
• Clostridiales
• Clostridium
– Obligate anaerobes
– Endospores
• C. tenani – tetanus
• C. botulinum - botulism
• Epulopiscium
– Very large bacteria
– Huge genome
– Endosymbiont in
surgeonfish
– Reproduces by releasing
cells through slit
Single Thiomargarita cell
• Thiomargarita
– gamma Proteobacteria
– Anaerobic chemolithotroph
that oxidizes sulfur and
reduces nitrates
– Even larger than
Epulopiscium
– Large vacuole to increase
surface area to volume ratio
Fruit Fly
Bacilli
• Bacillales
– Includes both rods and cocci
– Includes medically/ commercially
important genera
• Bacillus
–
–
–
–
–
Endospore-producing rods
Aerobe or facultative anaerobe
B. anthracis- anthrax
B. thuringiensis – insecticide
B. cereus - food borne illness
• Staphylococcus - grapelike clusters of cocci
–
–
–
–
–
facultative anaerobes
Yellow pigmented colonies
common inhabitant of skin and the nasal cavity
grows in foods with high osmotic pressure
S. epidermidis and S. aureus
–
–
–
–
–
–
–
–
S. aureus highly virulent
surgical wound infections
toxic shock syndrome toxin
enterotoxin - induces vomiting
exfolatin toxin – scalded skin syndrome
Folliculitis
Impetigo
MRSA and VRSA
• Lactobacillales
– Commercially important
– Aerotolerant or facultative anaerobes
• Lactobacillus
– Aerotolerant; Lactic acid fermenting rod
– common in vagina, intestinal tract, and oral
cavity
– used in production of pickles, buttermilk, and
yogurt
• Streptococcus
– chains of cocci
– Aerotolerant; Lactic acid fermenter
– Pathogenic strains produce multiple
extra-cellular enzymes and toxins
– Responsible for more illnesses and a
greater variety of diseases than any
other group of bacteria
• Beta-hemolytic streptococci
– S. pyogenes
• Impetigo, strep throat, scarlet
fever, necrotizing fascitis
• Alpha-hemolytic streptococci
– S. pneumoniae
• Pneumonia, ear infections,
sinusitis, meningitis
– S. mutans
• Dental carries
• Listeria
– Facultative anaerobe
– L. monocytogenes
– Contaminates dairy
products
– Psychrotroph
– Survives inside phagocytes
– May be responsible for
stillbirths and birth defects
Mollicutes (mycoplasmas)
• Mycoplasmatales
–
–
–
–
Wall-less, highly pleomorphic
Very small (0.1 - 0.24 µm)
May produce filaments
Degenerative evolution
• Mycoplasma
– M. pneumoniae
– walking pneumonia
• Spiroplasma
– Corkscrew morphology
– plant pathogen and parasite
of plant feeding insects
Actinobacteria
• High G + C
• Mycobacterium
– acid fast; aerobic rods;
filamentous growth
– non-endospore former;
mycolic acid
– M. tuberculosis – tuberculosis
– M. leprae - leprosy
• Corynebacterium
– Club shaped, metachromatic
granules
– C. diphtheriae –diphtheria
• Propionibacterium
• propionic acid fermenter
– Important in swiss cheese
production
– P. acnes commonly found on
human skin; primary cause of
bacterial acne
• Gardnerella
• gram variable; highly plemorphic
– G. vaginalis – bacterial vaginitis
• Actinomycetes
– Common soil inhabitants
– Branching filaments
– Asexual spores
– Frankia, Streptomyces, Actinomyces
• Streptomyces
– most antibiotics are produced by Streptomyces
species
– about 500 known species
– asexual spores (conidospores)
– Produce gaseous geosmin
• Actinomyces – facultative anaerobes
– mouth and throat of animals
– A. israelii - actinomycosis (tissue-destroying
disease affecting the head, neck, or lungs)
• Frankia
– nitrogen fixing bacteria
– Forms root nodules with alder trees
Domain Archaea
• Highly diverse morphology and physiology
• Frequently inhabit extreme environments
• Three primary groups are halophiles, thermophiles
and methanogens
• Currently classified into 3 Phyla
– Crenarchaeota
– Euryarchaeota
– Korarchaeota
Euryarchaeota
• Gram+ to gram variable halophiles, methanogens
and a few thermophiles
– Halobacteriales
• Obligate halophiles
– Bacteriorhodopsin based light capturing system
• Methanobacteriales
– Methanogens
• Convert CO2, H2
and organic acids
into methane
– Largest known group
of archaea
– Gram +; Obligate
anaerobes
Crenarchaeota
– Gram-; most thermophiles
– Sulfolobales
• acidophilic thermophilic sulfur metabolizers
– Desulfurococcales
• Hyperthermophiles
• Korarchaeota
– No members have ever been observed
– Known only from environmental rRNA
samples