BACTERIAL GROWTH CURVE AND BACTERIA Flashcards
Generation time can be every
30 minutes (E. coli) to every 24 hours (M. tuberculosis)
Increase in cell size, preparation to multiply
Adjustment/Lag phase
Increase in number of living cells; sensitive to antimicrobials
Exponential/Log phase
Equal number of dead and alive cells (constant number of cells); Decrease in nutrients; Increase in toxins; Sporulation occurs (Bacillus, Clostridium)
Stationary/Plateau phase
Increase in number of dead cells; more dead cells than alive cells
Death/Decline phase
In general Culture media preparation contains
pH: 7.2-7.4, distilled/deionized water; Dissolved till clear and no particles seen
Sterilization method for general culture media
AUTOCLAVE 121°C, 15PSI, 15 minutes
Sterilization method for heat-labile or delicate media
116-118°C or membrane filtration (pore size 0.2-0.45μm)
Types of Bacterial Culture
Pure culture, Mixed culture, Stock culture
Most common solidifying agent in bacterial culture
Agarose
Step after media sterilization and cooling
Add supplements (blood, vitamins, nutrients, or antibiotics)
Volume of cooled media dispensed on a 100 mm petri dish
20-25 mL at 55-60°C
LIQUID media examples
BHIB, THIO broth, TSB
SEMI-SOLID media example
SIM (0.5-1% agar)
SOLID media examples
TSI, MAC, CHOC (2-3% agar)
SYNTHETIC/DEFINED media
For research, all content is known
NONSYNTHETIC/COMPLEX media
Has some unknown content; examples: Nutrient broth, MAC
TISSUE CULTURE media for obligate intracellular organisms
Chlamydia, Rickettsia - McCoy, Vero, HeLa, Hep2
Sterilize and Dispense using petri dish
PLATED MEDIA
Dispense and Sterilize, examples: Agar Deep, Agar Slant, Butt-Slant media
TUBED MEDIA
Routinely used without special supplements for non-fastidious organisms (e.g., Nutrient agar, Trypticase soy)
SIMPLE/GENERAL PURPOSE/NUTRITIVE media
Grow certain groups with supplements while suppressing other flora (e.g., APW, Selenite F, BCYE, THIO, LIM)
ENRICHMENT MEDIA
For fastidious organisms (e.g., BAP, CAP)
ENRICHED MEDIA
Visualizes metabolic differences of bacteria (e.g., MAC, BAP, EMB, HEA)
DIFFERENTIAL MEDIA
Contains inhibitors to grow specific groups of bacteria (e.g., HEA, MAC, XLD, MSA)
SELECTIVE MEDIA
Isolate bacteria with specific requirements (e.g., LJ, TCBS, Cysteine agar)
SPECIAL MEDIA
Inhibitors that inhibit Gram-positive bacteria
Crystal violet, basic fuchsin, bile salt, sodium deoxycholate
Inhibitors that inhibit Gram-negative bacteria
Phenylethyl alcohol, potassium tellurite, sodium azide
Inhibitors for swarming Proteus spp
Alcohol, chloral hydrate
Base agar for Neisseria
Chocolate agar
Thayer Martin agar components
VCN (Vancomycin, Colistin, Nystatin)
Modified Thayer-Martin agar components
VCNT (Vancomycin, Colistin, Nystatin, Trimethoprim)
NYC agar components
VCAT (Amphotericin B)
Martin-Lewis agar components
VCAT (Amphotericin B, Anisomycin)
GC agar components
VCATL (Amphotericin B)
NYC agar supports growth of
Neisseria, Ureaplasma, some Mycoplasma
Antimicrobials for Neisseria culture media
Vancomycin, Lincomycin, Colistin, Nystatin, Amphotericin B, Anisomycin
Antimicrobials for Neisseria growth inhibition
Vancomycin (Gram positive), Colistin (Gram negative), Nystatin, Amphotericin B (Fungi)
