P1 Bacterial Cultivation (LECTURE) Flashcards
prelims
Refers to the increase in the number of bacteria rather than in size
- bacteria grow in number and do not grow in size
- This growth is affected by various factors such as optimum growth requirements, dynamics of growth, including the use of a medium that can be artificially prepared in the laboratory
Bacterial Growth
Bacterial Growth Requirements
- Nutrition
- Environmental
NUTRITIONAL REQUIREMENTS:
(C.ES.ES.N.W.ME.S.A/SGR.GR.TR.PHR)
- Carbon
- Energy Source
- Electron Source
- Nitrogen
- Water/Moisture/Humidity
- Mineral Elements
- Salt
- Additional/ Special Growth Requirements
- Gaseous Requirement
- Temperature Requirement
- pH Requirement
Needed for the synthesis of cellular components
Carbon
Carbon is at least ____ of weight
50%
Carbon Dioxide from the air
Autotroph
Organic compounds in the culture media (glucose)
Heterotroph
Energy source is ______ of weight?
4%
Light?
Phototroph
Chemical Energy?
Chemotroph
Electron Source
(I.O.N.F) “INOFF”
- Inorganic molecule (Fe2+)
- Organic molecule
- NADH reduced from NAD
- FADH2 reduced from FAD
- Inorganic molecule - litotroph
- Organic molecule - organotroph
Needed for the synthesis of proteins
Nitrogen
- Free nitrogen from the air
- Nitrogenous compounds in the culture media (e.g., peptone, yeast, beef extract)
Nitrogen is (___) of weight?
14%
Water/ Moisture/ Humidity is (_________) of bacteria
70%
Needed as co-factors in various metabolic process of the bacteria
Mineral Elements
Bacteria can tolerate salt concentration below (____)?
6%
certain bacteria that can survive high salt concentration environment
Halophilic bacteria or Halophiles (salt loving)
Bacterias that are Halophilic or Halophiles (salt loving):
(S.E.V.B)
- Staphylococcus spp.
- Enterococcus spp.
- Vibrio spp. (except: Vibrio cholerae & Vibrio mimicus)
- Bacillus spp.
Bacteria that are very difficult to grow
Fastidious
- requires special or additional requirements to grow in culture media
Example of blood loving organism?
Haemophilus spp.
Requires both X & V factor
Haemophilus spp.
Additional/ Special Growth Requirements
Culture media:
* intact RBC
* x factor only
Blood Agar Plate
Culture media: Blood Agar Plate
1st priority:
5% defribinated sheep’s blood
Culture media: Blood Agar Plate
2nd priority:
horse blood
Culture media: Blood Agar Plate
3rd priority:
Rabbit’s blood
Culture media: Blood Agar Plate
Least priority:
Human blood
(must be type O – no presence of antigens)
Since blood agar plate lacks V factor, use (____)?
Chocolate Agar Plate
contains NAD – v factor
* lysed RBC (heat)
* has v and x factor
Chocolate Agar Plate
hydrolyzes the NAD
NADase
hydrolyzed NAD means?
NAD = Nicotinamide Adenine Dinucleotide
No V factor
Degradation product of Hgb (hemoglobin)
X Factor (Hemin/ Hematin)
Gaseous Requirement
Bacteria that grow, live, and survive in the presence of oxygen
Aerobe
Gaseous Requirement
Absolutely requires oxygen to grown, live, and survive
Strict/Obligate Aerobe
Gaseous Requirement
Example of Strict/Obligate Aerobe bacteria?
(M.M.P.N.B.F.B.L) - spp.
- Micrococcus spp.
- Mycobacterium spp.
- Pseudomonas spp.
- Neisseria spp.
- Brucella spp.
- Francisella spp.
- Bordetella spp.
- Leptospira spp.
Gaseous Requirement
Bacteria that have the ability to grow, line and survive in small concentration of oxygen environment
Facultative Anaerobe
Gaseous Requirement
Example of Facultative Anaerobe bacteria?
(S.S.FE)
- Staphylococcus spp.
- Streptococcus spp.
- Family Enterobacteriaceae
Gaseous Requirement
Bacteria that prefers small concentration of oxygen environment
* approximately (_____)?
Microaerophilic
- 2%-10%
Gaseous Requirement
Example of Microaerophilic bacteria?
(C.H.A.S) - spp.
- Campylobacter spp.
- Helicobacter spp.
- Arcobacter spp.
- and some Streptococcus spp.
Gaseous Requirement
Bacteria that grow, live and survive in the absence of oxygen
Anaerobe
Gaseous Requirement
Absolutely do not requires oxygen to grown, live, and survive
Strict/ Obligate Anaerobe
Gaseous Requirement
Example of Strict/Obligate Anaerobe bacteria?
(C/CN.B.FB.PS.PR) - spp.
- many Clostridium spp. (Clostridium noyvi)
- Most Bacteroides spp.
- Fusobacterium spp.
- Peptostreptococcus spp.
- Porphyromonas spp.
Gaseous Requirement
Bacteria that do not require oxygen but may tolerate or withstand limited exposure to oxygen
Aerotolerant Anaerobe
Gaseous Requirement
Example of Aerotolerant Anaerobe bacteria?
(C [CP,BF])
(PB & LB)
- Some Clostridium spp. (Clostridium perfringens, Bacteroides fragilis)
- Most strains of Proprionibacterium & Lactobacillus
Gaseous Requirement
Bacteria that requires 5%-10% CO2 to grow
Capnophilic
Gaseous Requirement: Capnophilic
N.H.A.CB.E.K.SP GROUP
- Neisseria spp.
- Haemophilus spp.
- Aggregatibacter spp.
- Cardiobacterium spp.
- Eikenella spp.
- Kingella spp.
- Streptococcuse pneumoniae
Most pathogenic bacteria would grow at temperature between 35-37C
- hence incubator in the laboratory is usually set and maintained within this temperature range for routine isolation of pathogens
Temperature Requirement
Temperature Requirement
- Mesophilic
- Psychrophilic/Cryophilic
- Thermophilic
- Hyperthermophilic/ Extremely Thermophilic:
- Eurithermophilic:
- Sternothermophilic:
- 20-40C
- 0-20C
- 50-60C
- 80-110C
- wide range
- narrow range
most pathogenic bacteria can grow in a neutral or slightly alkaline environment
hence most culture media used in routine isolation of pathogens is adjusted to this (____)
pH Requirement
(pH range)
pH requirement (___)
pH 7.0 – 7.5
pH Requirement
Acid loving bacteria
Acidophilic
pH Requirement
Example of acid loving bacteria?
(LB.A)
Lactobacillus acidophilus
normal flora of vagina
pH Requirement
Alkali loving bacteria
Alkaliphilic
pH Requirement
Example of alkali loving bacteria?
(GV)
Gardnerella vaginalis
pH Requirement
Osmophilic bacteria
High Osmotic Pressure
pH Requirement
Example of osmophilic bacteria
(AB spp.)
Archaebacteria spp.
Bacterial Growth Phase
- Generation time
- Fast Growing Bacteria
- Slow Growing Bacteria
- Time to replicate & Refers to the stages of bacterial growth
- 20 minutes
- 24 hours
4 Bacterial Growth Phase:
- Lap Phase
- Log/Logarithmic/Exponential Phase
- Maximum stationary/Plateau phase
- Decline/Death phase
Bacterial Growth phase:
Bacteria are still adjusting to the new environment hence there is no cell division that occurs in this phase
they are activity synthesizing DNA & proteins that are necessary for cell division
Lag Phase