U3 LEC: BACTERIAL MORPHOLOGY AND GENETICS Flashcards
Size of bacteria
0.4 to 2um
Bacteria free water
less than 0.4 or 0.5
T/F: Not all cocci are round.
True
Strep
chains
Staph
clusters
Diplo
cocci in pairs
Bean / kidney / coffee bean shaped
Gram (-) diplococci
- Neisseria gonorrheae
- Neisseria meningitidis
Lancet shaped
Gram (+) diplococci
- Streptococcus pneumoniae
Bacilli
chains, picket fences, cigar packet
Palisades
Bacilli
Squared off ends
Gram (+) bacteria
- Bacillus anthracis
Bacilli
Thin or short
Vibrio
Bacilli
Slightly curved
Campylobacter jejuni
Bacilli
Robust
Gram (+) bacilli
Inverted christmas tree
Listeria monocytogenes
Chinese letters
Corynebacterium diphtheriae
School of fishes
Haemophilus ducreyi
Fried egg appearance
Mycoplasma
Railroad tracks
Haemophilus sp.
Bacteria that causes orchitis
Brucella abortus
Medically relevant spirochetes
- Leptospira interrogans
- Treponema pallidum
- Borrelia burgdorferi
Corkscrew form
Borrelia burgdorferi
Genetic potential of the organism’s DNA
Genotype
Expressed genetic characteristics
Phenotype
Prokaryotic transcription and translation occurs in the?
cytoplasm
Single dsDNA, closed, circular, supercoiled bacterial chromosome
Bacterial Genome
Extrachromosomal dsDNA, not essential for growth
Plasmids
Plasmids are significant in?
antibiotic resistance
Mobile Genetic Elements
- Transposons
- Insertion Sequence Element
This is mobile, can jump from one place in chromosome to another
Transposons
Transposons are significant in?
antibiotic resistance
This is the simplest mobile piece of DNA, causes disruption and inactivation of gene.
Insertion Sequence Element
Gene transfer/exchange between homologous regions on 2 DNA molecules.
Genetic Recombination
take up of naked DNA into bacterial cell
Transformation
Bacteria under Transformation
- Streptococcus pneumoniae
- Neisseria gonorrhoeae
- Haemophilus influenzae
transfer of genes by a bacteriophage
Transduction
Bacteria under Transduction
Corynebacterium diphtheriae
Refers to the phage in lysogeny
Temperate
transfer of genetic material from a donor to a recipient strain
Conjugation (Sex Pili / Conjugation Pili)
changes in the base sequence of DNA, insertions and deletions
Mutations
This is due to tautomeric shift of electrons in bases.
Spontaneous
This is due to mutagens.
Induced
2 Basic Groups of Bacteria
- Autotroph (Lithotrophs)
- Heterotroph
Bacteria that use carbon dioxide as source of carbon
Autotroph (Litotrophs)
Bacteria that require complex substances for growth
Heterotroph
Photoautotroph
Light, CO2
Photoheterotroph
Light, Organic Compounds
Chemoautotroph
Organic compound, CO2
Chemoheterotroph
Organic compounds
Growth requirements (Nutrients)
- Carbon source
- Nitrogen source
- Energy source
- Metallic Elements
- Organic substances
- High osmotic pressure
Growth requirements (Nutrients)
Synthesis of cell components
Carbon source
Growth requirements (Nutrients)
protein synthesis
Nitrogen source
Growth requirements (Nutrients)
for enzyme activation
Metallic Elements
Growth requirements (Nutrients)
under Metallic Elements
Mg, K, Fe, Cl, Na, Ca
Growth requirements (Nutrients)
Examples of organic substances
Amino acids
Growth requirements (Nutrients)
Example of osmophilic bacteria
Archaebacteria
Additional requirements for Fastidious organisms
- Blood
- Protein
- Salt
- Cysteine
Blood
X and V factors
Hemin and Nicotinamide adenine dinucleotide (NAD)
Blood is for what species?
Haemophilus spp.
Protein is used for what species?
Mycobacterium
Traditional carbon source of Mycobacterium species
potato starch and soy medium agar
Protein can be in the form of?
bovine albumin
How are proteins sterilized?
through <0.5 - <0.4 small pore size filters
Halophilic bacteria
Vibrio
This bacteria is positive in 5% NaCl.
Enterococcus
This bacteria needs cysteine to grow.
Legionella pneumophila
Medium with Cysteine for Legionella
Buffered Charcoal Yeast Extract (BCYE)
Agar that only has X factor
Blood Agar Plate
T/F: BAP has V factors but only manifested if organism is hemolytic.
True
Hemolyzed blood agar, has both X and V factors.
Chocolate Agar
CAP is placed in?
candle jar
Agar for aerobic conditions, gram (-) organisms, has crystal violet
MacConkey Agar
has 7.5% NaCl, for Staphylococcus sp.
Mannitol Salt Agar
has 4% NaCl
Mueller Hinton Agar
Environmental Factors
- Temperature
- pH
- Oxygen and Carbon Dioxide availability
- Moisture
pH range
6.5 to 7.5
Exceptions for pH
- Lactobacillus acidophilus
- Vibrio cholerae
- Streptococcus agalactiae
- Escherichia coli
20-40C
Mesophilic
Only bacteria that grows beyond 40C (42C)
Pseudomonas aerigunosa
50-60C
Thermophilic
<20C, food and water
Psychrophilic
Bacteria under Psychrophilic
- Staphylococcus aureus
- Listeria monocytogenes (dairy)
Short optimum temperature range
Stenothermophilic
Wide temperature range
Eurithermophilic
Gaseous requirements
- Strict/Obligate Aerobe
- Strict Obligate Anaerobe
- Facultative Anaerobe
- Aerotolerant
- Microaerophilic
- Capnophilic
How to tell if it is anaerobic
- deep seated infection
- very foul-smelling (sulfur)
- blackening in the area
- sandy granules
Bacteria under Capnophilic
- Neisseria
- HAECK (Haemophilus, Actinobacteria, Cardiobacterium, Eikenella, Kingella)
- Bacillus anthracis
- Mycobacterium tuberculosis
Major constituent of both agar & broth media
Water
Solid media
1-2%
Semi-solid media
0.5% (SIM, MIO)
Broth media
<0.5%
Bacterial numbers increase through?
Binary fission
Bacterial Growth
20 minutes
Escherichia coli
Bacterial Growth
24 hours
Mycobacterium tuberculosis
Growth rate is in terms of?
generation per hour
Other term for Petroff Hausser Counting Chamber
Neubauer Counting Chamber
Oxygen stable, active
Surface Hemolysis
Oxygen labile, sensitive, hemolysin cannot be exposed
Subsurface Hemolysis
T/F: The use of pure cultures must be observed in the pour plate and spread plate methods.
True