Module 2 - Notes Flashcards
Prokaryotes are divided into which 2 groups?
Bacteria & Archaea
Which morphological features do we use to define bacterial species?
Shape
Staining Patterns
Biochemical Tests
Growth Patterns
How do we use genetics to define bacterial species?
97% 16s rRMA identity
As genetic technology has improved, the definition of bacteria species has evolved.
What are the 5 groups of bacteria that were discussed in the lectures?
Proteobacteria
Non-proteobacteria gram-negative
Actinobacteria
Firmicutes
Deep branching bacteria
Proteobacteria can be subdivided into which groups?
Alphaproteobacteria
Betaproteobacteria
Gammaproteobacteria
Deltaproteobacteria
Epsilonproteobacteria
What are the properties of proteobacteria?
16s rRNA gene sequencing
Gram-Negative
subdivided into 5 groups
What are the properties of alphaproteobacteria?
Oligotroph (Grow in low nutrient environment)
Fix nitrogen
What are 2 examples of alphaproteobacteria?
Chlamydia
Rickettsiae
What is unique about the Chlamydia life cycle?
form elementary bodies that are infectious
bind to host cells and then invade them.
they become reticular bodies (most metabolically active form)
replicates within the cell
differentiates into elementary bodies and eventually kills the host cell
cells are released and spread to other healthy cells.
What are the properties of betaproteobacteria?
Eutroph (grow in high nutrient environment)
What are some examples of betaproteobacteria?
Neisseria
Meningitis & Gonorrhoea
Bordetella pertussis
= Whopping Cough
both are obligate human pathogens (only live in humans)
What are the properties of gammaproteobacteria?
largest & most diverse group
aerobic or facultative aerobes
(need oxygen) but (can grow in the absence of oxygen)
What are some sample families of gammaproteobacteria?
Pseudomonaceae
Pasteurellaceae
(important in agriculture)
Vibrionaceae
Legionellaceae
Enterobacteriaceae
(important in gasterointestinal tract)
Enterobacteriaceae can be split into 2 groups which are
Coliforms & Non-coliforms
What are coliform enterobacteriaceae?
Bacteria that ferment lactose
(acid & gas production)
Escherichia Coli
What are non-coliform enterobacteriaceae?
Bacteria that do not ferment lactose
(no acid or o gas)
Salmonella
What are the properties of Deltaproteobacteria?
Sulphate reducing bacteria
What are some examples of deltaproteobacteria?
Bdellovibrio
vampire/predatory bacteria that kills other bacteria
Myxobacteria
- slime bacteria
- motile & highly social
- survive harsh conditions
- thick cell wall
What are the properties of Epsilonproteobacteria?
Smallest group
microaerophilic
(they need oxygen but if they get too much they die)
What are some examples of Epsiolonproteobacteria?
Campylobacter
gives you bad stomach or intestinal infection
Helicobacter
gives you gastric ulcer
How can you differentiate between alphaproteobacteria and betaproteobactiera?
Their ability to grow in a low or a high nutrient environment
Oligotroph vs Eutroph
Non-proteobacteria Gram-Negative can be divided into the following 4 groups
Spirochetes
CFB (Cytophaga, fusobacterium, bacteriodes)
Planctomycetes
Phototrophic bacteria
What are the characteristics of spirochetes?
long thin spiral-shaped
(corkscrew)
difficult to gram stain
best seen using darkfield fluorescent microscopy
axial filament (flagella) for mobility
What are some examples of spirochetes?
Borrelia
responsible for lyme disease
Treponema
syphilis
What are the characteristics of CFB?
Cytophaga
Fusobacterium
Bacteroides
rod-shaped bacteria
anaerobic bacteria
(strict or aerotolerant)
Fermenters
What are the characteristics of Planctomycetes?
Aquatic environments
Budding cell division
Swarmer cells & Sessile cells
What are the characteristics of phototrophic bacteria?
carry out photosynthesis
oxygen-producing bacteria
cyanobacteria
What are the common characteristics of actinobacteria?
High G + C gram-positive bacteria
very diverse
found in the soil but some are aquatic
majority are aerobic
What are some examples of actinobacteria?
Acid-fast bacteria
Mycobacterium
Corynebacterium
- diptheria
*Bifidobacterium
- anaerobic
What are the common characteristics of Firmicutes?
Low G + C gram-positive bacteria
also known as Bacillota
there are 4 sub-groups
What are the 4 sub-groups of firmicutes?
Clostridia
Lactobacillales
Bacilli
Mycoplasma
What are the characteristics of clostridia?
obligate anaerobes
Endospores
What is an example of Clostridia?
Clostridium
tetanus
What are the characteristics of Lactobacillales?
Lactic acid bacteria
Ferment yogurts and cheeses
What are some examples of lactobacillales?
Listeria
Lactobacillus
- Leuconostoc*
Enterococcus
Streptococcus
What are the characteristics/examples of Bacilli?
Bacillus
Aerobic or facultative anaerobe
Endospore former
Staphylococcus
facultative anaerobes
What are the characteristics of Mycoplasma?
Special Group
No cell wall, no peptidoglycan
not gram-stainable
small and pleomorphic (many different shapes)
How do you differentiate a clostridia from a bacilli?
the oxygen requirements
obligate anaerobe vs obligate aerobe/facultative anaerobe
What defines the Deep Branching Bacteria?
Evolved from ancient and extinct forms of life
Adapted to the harshest/extreme conditions
What are some examples of deep branching bacteria?
Deinococcus radiodurans
- not killed by high radiation
Thermotogae
- stain gram-negative (sheath-like outer membrane)
- anaerobic
Aquificae
- adapted to the harshest conditions
How do you differentiate between a Thermotogae and gram-negative bacteria?
The composition of the outer membrane
Thermotogae has a sheath-like outer membrance
