Growth control Flashcards
Decontamination?
Wiping
Sterilization?
Remove all microorganisms
Disinfection?
Agents that kill or inhibits growth
Sterilants?
Sterile –> Destroy all microorganisms + endospores
Disinfectants?
Kill microorganisms but not endospores
Sanitizers?
Reduce the number but do not kill
Antisepticts?
Kill or inhibits growth
3 antimicrobial controls?
H
R
F
Heat?
Measured in D = 10fold reduction in viability
Moist heat has better penetration @ given T
Thermal death time?
Basically the t for all cells to be killed. Sample heated –> medium –> incubated
Autoclavation?
Sterilization with steam under P @ high T a smaller sample - less t large sample - more t
Pasterurization?
Do not kill endospores
Reduces the nr of midroorganisms in food and increases the shelf life.
Flashpasteruization is a developed method
Radiation?
UV - for disinfection
Ionization?
Basically energy that penetrates and kills.
Have difficulty killing endospores, virus and resistant microorganisms.
Filter?
Used for not T sensitive and and no ionization. Pores that are 0.2um but cannot catch viruses.
Depth?
Sheets of glassfiber
HEPA
Pores >0.3um that removes from air
Membranes?
Used in labs. Small polymers with a high number of small pores.
Syringe/pump for (l) to a sterile vessel
Nucleopore?
Polycarbonate film + radiation + chemicals that isolate specimens for scanning in electron microscope.
Bacteriocidal agents?
Kills but do not bind and lyse
Bacteriostatic agents?
Inhibits and binds weak
Bacteriolytic agents?
Kills by binding and lysing
5 basic mechanisms for agents?
Inhibit cellwall synthesis Inhibits translation Alternates the cell membrane Inhibits nucleic acid synthesis Antimetabolite activity
MIC?
Minimum inhibatory concentration
Smallest amount that completely inhibits growth
E-test?
Plastic strip + [] of microbial agent to agar platform. From plate to agar and forms an eliptical zone of inhibition where the eclipse meets the strips mic.
Kirby-Bauer test?
Disc diffusion test for sensitivity or resistance of aerobes and anaerobes. Produces an inhibatory zone = no growth and the lowest [] with longest D into the media has the highest sensitivity to the bacteria.
Zone of inhibition?
It is compared to a chart: Sensitive Resistant Intermediate Basically zone of I + MIC value
