Bacteria Classification Flashcards
What is the system institued by Carolus Linnaues for naming microorganisms
Binomial nomenclature
What are the two parts of a microorganism name
Genus name and specific epithet (species
Also trivial names as well
What is a eukaryotic species
A group of closely related organisms that interbreed among themselves (Dogs)
Prokaryotic species
A population of cells with similar characteristics
Clone
Population of cells derived from a single cell
Strain
Genetically different cells within a species
What are the levels of nomanclature from specific to broad
Species - Genus - Family - Order - Class - Phyllum - Domain
Related species are placed within the same _________
Genus
Related genera (genus) are placed within the same _______-
Family
Family names end in
Aceae
Order names end in
Ales
What are the five ways microorganisms are identified
Morphological characteristics
Differential staininng
Biochemical tests
Serological (antibodies)
Molecular Biology technique (most accurate)
Morphological identification of microorganisms
Based on cell wall, cell shape etc.
Dichotomous keys
Identification method based on successive questions with each Q having 2 possible answers (usually yes or no)
Enterics
bacteria whose natural habitat is the GI tract; contain pathogens that cause diarrhea
Two domains of unicellular organisms within prokaryotes
Archaea and bacteria
Bacteria domain breaks down further into
Gram negative:
- Proteobacteria
- Nonproteobacteria
Gram-Positive:
- Low G+C
- High G+C
What is the main strategy used to distinguish bw bacteria
Gram staining
Examples of Nonproteobacteria
Chlamydiae
“Chlamydia trachomatis”: STD and eye infections.
Spirochetales:
- Borrelia burgdorferi: Lyme disease
- Treponema pallidum: Syphilis
Why are proteobacteria called what they are?
After a Greek god that could assume many shapes (Like proteobacteria)
Five classes of proteobacteria
Alpha (a) - proteobacteria,
beta (b) -
gamma (g) -
delta (d) -
epsilon (e) -
Alpha-proteobacteria
M/os that grow at low level of nutrients
Include agriculturally important bacteria
Include human pathogens
Brucella: Causing brucellosis (to do with diseases contracted from animals)
Rickettsia: Resulting in sportted feveres (transmitted from insects)
Brucella
Brucellosis: Genre of zoonotic diseases causesd by animal contact and unpasteruized milk products
Alpha-proteobacteria
Rickettsia
Arthropod-borne, Spotted fevers
Alpha-proteobacteria
Examples of Beta proteobacteria
Neisseria:
Causing meningitis and Gonorrhoeae
Bordetella: Whooping cough
Gamma-Proteobacteria
Largest subgroup of proteobacteria
Includes enterics
- Escherichia
- Salmonella
Shigella
ALSO
Vibrio cholerae
Which is the largest subgroup of proteobacteria?
Gamma
Epsilon Proteobacteria (Main one)
Helicobacter: H. Pylori
What is considered to be a low Guanine and cytosine content for G+ bacteria?
Below 55%
3 major classes of Gram Positive bacteria
Mollicutes (Myoplasmas)
Clostrida (Clostridias)
Bacilli
Mollicutes (Myoplasmas)
Class of Low G+C Gram+
WITHOUT WALLS
Therefore pleomorphic
One example of myoplasmic bacteria
Mycoplasma pneumoniae
Causes atypical pneumonia
Clostridias
Low G+C Gram+ WITH walls
Anaerobic
Clostridium
Produce endospores
Name variants of clostridium
Botulism
Tetanus
Gas gangrene
Diarrhea and colitis
Bacilli (class of G+)
Low C+G
Aerobic
HAVE cell wall
Produce endospores
Ex of bacilli G+
Staphylococus: S. Aureus (Food poisoning)
Lactobacilli
Type of G+ Low G+C bacteria WITH a cell wall
DO NOT produce endospores
Ex of lactobacillie
Lactobacillus (Normal flora of V)
Listeria (Food poisioning)
Streptococcus (strep throat, impetigo…)
Enterococcus (UTIs, Endocarditis)
Ex of High G+C Gram+
Include
Actinomycetes
Mycobacteria
Propionibacterium
Gardenerella vaginalis
Methanogens are a type of
Archaea
what one key feature of salmonella as seen on the dichotomous keys
Would produce black precipitate (hydrogen sulfide)
Members of the order Enterobacteriales are
Gram-negative, facultatively anaerobic rods
major point of distinction amongst members of the order Enterobacteriales
Some members ferment lactose, others are non-lactose fermenters.
most likely mode of transmission for healthcare-associated Serratia infections?
Direct contact with the contaminated hands of healthcare personnel
Do algae cause infection?
Although algae don’t cause infections directly, some species can produce toxins that cause disease in shellfish, fish, marine mammals, and occasionally in humans who have consumed the shellfish or fish
Why is visualization not sufficient to properly identify bacteria?
Bacteria have a limited set of shapes and many unrelated bacteria share the same shape.
What is the main methods used to identify unknown bacteria
Biochemical tests
What test result indicates that the unknown can utilize citrate as its sole carbon source?
The medium turns blue.
How is fermentation of lactose detected?
The drop in pH turns the indicator dye yellow an gas may or may not be produced
Prokaryotic cells, ester linkages in phospholipids
Which is the best differentiators bw the three-domain system?
There are significant differences in nucleotide sequences in ribosomal RNA between all three domains.
The phylogenetic classification of bacteria is based on ________.
ribosomal RNA (rRNA) sequences
What is the distinct characteristic of the members of the Kingdom Fungi?
They absorb dissolved organic matter.
A genus can best be defined as
a taxon composed of one or more species and a classification level lying below family.
Describe the order Enterobacteriales
Members of the order Enterobacteriales are Gram-negative, facultatively anaerobic rods.
major point of distinction amongst members of the order Enterobacteriales?
Some members ferment lactose, others are non-lactose fermenters.
most likely mode of transmission for healthcare-associated Serratia infections?
Direct contact with the contaminated hands of healthcare personnel
Why are doxycycline and rifampin ideal agents for treating intracellular pathogens such as Brucella and Mycobacteria?
Both agents provide for good penetration of body tissues and reach therapeutic levels.
A key point in treatment for infections of intracellular pathogens is penetration of the antibiotic into host cells and tissues where the organism resides.
describe the bacterial group found primarily in the intestines of humans?
Facultatively anaerobic gram-negative rods
70S ribosomes
are contained within both Eukaryotic and prokaryotic organims
Do E and Ps both contain RNA? DNA?
Prokaryotes and eukaryotes contain both RNA and DNA
Are eukaryotes always multicellular?
Can be unicellular or multi
If two bacteria are gram positive, but one is low G+C and the other is high G+C, what can be concluded?
The organisms are unrelated
best reason to classify streptococcus in the lactobaciallaes
rRNA sequences
