1.1.1 Cultivation of bacteria Flashcards
Process of growing microorganisms in culture by taking bacteria from in vivo (Infection site) to In vitro environment (Artificial environment)
Bacterial cultivation
What is in vivo environment in Bacterial cultivation?
Infection site
What is in vitro environment in Bacterial cultivation?
Artificial environment that mimics in vivo
What are the main purpose of Bacterial Cultivation
To grow and isolate
To determine which bacteria that grow that causes infection
To obtain sufficient growth of clinically relevant bacteria to allow Identification, characterization, and susceptibility testing
What are the nutritional needs for bacteria?
Carbon
Nitrogen
Non-metallic elements (Sulfur, phoshorus)
Metallic elements
Vitamins
Water
Energy
Most essential and central atom common to all cellular structures and functions
Carbon
Organisms requires inorganic compounds or carbon
Autotrophs (CO2)
Organisms requires organic compounds or carbon
Heterotrophs (Carbohydrates)
Essential atom for proteins and nucleic acid
Nitrogen
Type of proteins that is responsible for metabolic activities
Enzymes
Example of Non metallic elements?
Sulfur
Phosphorus
Integral to some amino acids and component of proteins
Sulfur
What is the source of sulfur for organic compounds
amino acids
What is the source of sulfur for inorganic compounds
Sulfates
Non metallic elements that forms the nucleic acid DNA and RNA
Phophorus
Phosphorus synthesize a high energy organic compound called?
Adenosine triphoshate
What is phosphorus being supplied to the cell?
Phosphate salt
What are the metallic elements
Calcium, Zinc, Sodium, Potassium, Copper, Manganese, Magnesium Ferrous, and Ferric
What are the activities for metallic elements?
Osmoregulation,
Regulation of enzyme activity,
Electron Transport
How is metallic elements present in the body?
Present in small amounts and are supplied by inorganic salts
Sources of coenzymes which are required for the formation of active enzyme systems
Vitamins
Vitamins are present in _____ amount and produce by?
Small
Organic substance
Universal medium requires to cross the cell membrane
water
Purpose of energy?
Active transport
Biosynthesis
Biodegradation of macromolecules
Bacteria requires radiant energy
Phototrophs
Dependent on oxidation of chemical compounds
Chemotrophs
Nutrients are incorporated on or in which bacteria are grown?
Culture media
What are the consideration for culture media?
Growth requirements
Optimal environmental conditions
Bacteria that needs relatively complex, and exceptional media components
Fastidious microorganisms
Bacteria that needs relatively basic and straightforward nutrients (Clinicaly important bacteria)
Non-Fastidious micoorganisms
NOTE:
Additional requirement nutrients require for the growth of fastidious microorganisms
What is the difference between broth and Plate
Concentration of agar
What is the basis for growth in broth/Culture media?
Turbidity
The higher the turbidity, ____________
more cell density
How many to know if the bacteria is in the broth?
10th to the 6th bacteria/mm of broth
What is the basis for growth of bacteria in agar?
Colonies
Composed of KNOWN quantities of chemically pure, specific organic and/or inorganic compounds.
Their use requires knowledge of the organism’s specific nutritional needs
Chemically defined media / Minimal media
Example of Chemically defined media?
Inorganic synthetic broth
Glucose salts broth
The Exact chemical composition of these media is NOT KNOWN.
They are made of extracts of plants and animal tissue and are variable in their chemical composition
Complex media
Example of complex media?
Nutrient agar
Yeast Extract broth
This type of medium is not usually used in diagnostic microbiology laboratory
Chemically defined media (Minimal media)
This type of medium is not usually used in diagnostic microbiology laboratory
Chemically defined media (Minimal media)
Components of Nutrient agar
peptone (Nitrogen)
Beef extracts (Organic carbon, vitamins, inorganic salts)
Contain specific nutrients required for the growth of particular bacterial pathogens.
Enrichment media
Example of Enrichment media?
Buffered charcoal-yeast extract agar (BCYE)
What bacteria can grow on BCYE?
Legionella pneumophila
Nocardia
Used to ensure growth of an organisms when no organisms grow on solid media after initial specimen inoculation
Enrichment broths
Causative agent of Legionnaires disease
Legionella pneumophila
What contains in BCYE for the growth of Legionella pneumophila?
L-cystine
Example of Enrichment broth?
Thioglycollate broth
Todd-hewitt broth
Gram negative broth (GN broth)
What is the purpose of Thioglycollate broth?
Separation anerobic microorganisms
What is the component for Todd-Hewitt broth?
Colistin and Nalidixic acid
What bacteria grow on Todd-Hewitt broth?
Streptococcus agalactiae
What is the purpose of GN broth?
Enrich Enteric gram negative microorganisms
Contain nutrients that support growth of most non-fastidious organisms WITHOUT any particular organisms a growth advantage
General purpose
Nutritive media
Example of Nutritive agar
Tryptic soy agar/broth
Nutrient agar (Bacteria)
Sabouraud’s dextrose agar (Fungi)
Contain one or more agents that are inhibitory to all organisms except those “selected” by the specfic growth condition or chemica
Selective media
Examples of inhibitory agents
Dyes (Crystal violet)
Bile salts
Alcohols
Acids
Antibiotics
BAlAcDAn
Example of Selective media?
Phenylethyl alcohol with 5% SBA
What is the purpose of PEA?
inhibits the growth of aerobic and facultatively anaerobic gram-negative rods
Employ some factor/s that allow colonies of one bacterial species or type to exhibit certain metabolic or culture characteristics that can be used to distinguish then from other growing on the same agar plate
Differential media
Example of Differential media?
MacConkey agar
Media used in diagnostic bacteriology that provide more than one function
Combination media
Differentiate lactose fermenter from non lactose fermenter
MacConkey agar
Positive indicator for MacConkey
Pink colonies
Negative indicator for MacConkey
Colorless
Components of MacConkey agar?
Bile salts
Crystal violet
- Inhibits Gram positive cocci
