GENERAL PRINCIPLES IN MICROBIOLOGY (PART 1)

Reduces/inhibit pathogenic microorganisms but not all (prions, viruses, endospores etc.); prolonged exposure may destroy bacterial endospores; Cleaning laboratory surfaces, working area, bathrooms; Household bleach, phenols (e.g., Lysol), glutaraldehyde, alcohol

• DISINFECTION
• DECONTAMINATION
• STERILIZATION

Removal of pathogenic organisms for safe handling; Treatment of infectious waste prior to disposal; onizing radiation, halogens, peracetic acid, autoclave, incineration

• DISINFECTION
• DECONTAMINATION
• STERILIZATION

Complete elimination of all vegetative cells including spores and viruses; Preparation of surgical equipment and needles for injection, etc.; Autoclave, biocides, radiation

• DISINFECTION
• DECONTAMINATION
• STERILIZATION

Kills/inhibits multiplication of microorganism; Cleaning injured skin or in preparation of surgical procedures; Iodophor, 70% ethyl alcohol

• ANTISEPSIS
• DEGERMING

Reduction of microbial load by gentle to firm scrubbing; Handwashing; Soap and water, alcohol

• ANTISEPSIS
• DEGERMING

DRY HEAT: Dehydrates cell wall; denatures protein; Used to treat infectious waste; burned to ashes at high temp.; recommended for prions and infective proteins; Ashes produced are toxic and presence of heavy metals are observed

• INCINERATION
• DRY HEAT OVEN

DRY HEAT: Dehydrates cell wall; denatures protein and nucleic acid by disrupting cell membrane; Used to sterilize glassware, oil, petroleum, or powder; Requires longer exposure time compared to moist heat

• INCINERATION
• DRY HEAT OVEN

INCINERATION

• 870°C to 980°C
• 160°C- 180°C 1-3 hours

DRY HEAT OVEN

• 870°C to 980°C
• 160°C- 180°C 1-3 hours

MOIST HEAT: *Most efficient method; Coagulates and denatures structural proteins and enzymes irreversibly; Sterilization of biohazardous trash and heat-stable objects

• AUTOCLAVE
• BOILING