Sterilization
kills all microbes present
Disinfection
reduces the number of pathogens
Sanitization
reduction in the number of microbes present to a safe level
Heat
most common, effective, and inexpensive method
Moist Heat
Boiling
kills vegetative cells
Autoclave
steam under pressure
Pasteurization
heat material to a specific temperature for a specific amount of time, cool rapidly
dairy, wine, beer
Dry heat
hot air ovens
incineration
Incineration
loop sterilization
Filtration
solids physically separated from liquids by passage through filters with extremely small pores
used for materials that can't be heated, beer, wine, swimming pools, sewage, air, allergen testing
Two types of radiation
ionizing rays (gamma, xray)
nonionizing (UV)
Preservation
increased osmotic pressure
Desiccation
Acid, alkaline, pH
Decreased temperature
Lyophilization
Desiccation
drying, removal of water
Refridgerator
retards growth, does not prevent
Freezer
prevents growth, does not kill all organisms
Lyophilization
materials rapidly frozen at temps. well below 0 C
Disinfectants
used on inanimate objects
Antiseptics
used on viable tissue
Cide
killing effect
Static
inhibits growth
Ethylene Oxide
inactivate proteins, acts on nucleic acids
destroys all types microorganisms
Chemotherapy
use of chemical agents to treat disease
Chemotherapeutic agent
chemical agents used for treatment
Types of antimicrobial agents
Synthetic agents
Natural agents
Semi-synthetic agents
Effectiveness of antimicrobial agents
Selective toxicity
Broad spectrum
Non-mutagenic
Soluble in body fluids
Stable in body fluids
Absorbed by tissues
Non-allergenic to host
Should not disturb host's normal flora
Competitive inhibition
competes with essential substrate to act with microbial enzyme
Noncompetitive inhibition
reacts directly with enzyme
Sulfonamides
Inhibits synthesis folic acid by competitive inhibition
Bacteriostatic
Penicillin
Binds to & inhibits enzyme
Bactericidal
Erythromycin
Binds to bacterial ribosome
Bacteriostatic
Tetracyclines
Binds to bacterial ribosome
Bacteriostatic
Chloramphenicol
Binds to bacterial ribosome
Bacteriostatic
Streptomycin
Binds to active site on ribosome
Bactericidal
Quinolones
Inhibits DNA gyrase
Rifampin
Inhibits RNA polymerase
AZT
Inhibits reverse transcriptase
Ribavirin
Act as guanine analogues
Prevents viral replication
Griseofulvin
Prevents mitosis fungi
Binds to keratin
Polymixins
Causes cleavages (openings) in cell membrane
Bacteriocidal
Avoid antimicrobial agent disadvantages
Avoiding indiscriminate use of AMA
Maintain proper levels
For sufficient (prescribed) length of time
Use a combination of 2 or more AMA when resistance develops - synergistic effect
Do antibiotic sensitivity test to determine the most effective AMA