M1 & Sterilization and Disinfection

Cotton swabs with wooden shaft

70% isopropyl alcohol

Cleaning material for microscope

1. Brightfield or Light Microscope

2. Phase-contrast microscope

3. Fluorescence Microscope

4. UV light

5. Electron microscope

Types of Microscope

Brightfiled or Light Microscope

Forms a fark image against a brighter background,
hence the name

phase contrast microscope

Phase contrast microscope
 The condenser is similar to that of dark field
microscope
 The __ converts these tiny
differences into changes in light intensity (brightness
and contrast), making transparent specimens visible
without staining

Fluorescence Microscope

By the use of dyes, some microorganisms and
particles having low wavelength which is invisible to
eye are converted into longer wavelength which is
visible to the eye

UV light

This method is used for demonstration of
microorganisms; naturally occurring fluorescent
material or particles after staining with some
fluorescent dyes eg. M. tuberculosis.

Electron microscope

a micriscope that uses an electron beam to create an image, with elctromagnets acting as lenses

• Transmission electron microscope

• Scanning electron microscope

types of electron microscope

Transmission electron microscope

creates images of a sample's internal
structure by analyzing electrons that pass
through it, providing high-resolution 2D
projections

Scanning electron microscope

images a sample's surface by detecting
reflected or emitted electrons as a focused
beam scans its topography, producing 3D-
like views

• Brucellosis

• Tuberculosis

• Shigellosis

• Salmonellosis

• Hepatitis

5 most common laboratory-acquired infections:

Proper handwashing

Most common practice to prevent the spread of disease?

N95 mask

surgical mask

Airborne precaution

HCW wears __ while the patient wears a
_

surgical mark

Droplet precaution

HCW wears _ when working within 3 feet
of patient

Gown, Mask, Goggles, Gloves

Donning:

Gloves, Gown, Goggles, Mask

Doffing:

Gloves

Minimum required PPE?

Sterilization (Biocide)

is a provess whereby all forms of microbial life, including bacterial spores are killed

Heat

• Moist Heat - Autoclave, Fractional

• Dry Heat - Flame, Oven, Incineration, Cremation

Filtration

Ionizing Radiation

Physical Method (STERILIZATION):

Bacillus stearothermophilus

Autoclave- Quality control spored of _____

Autoclave

Most effective method for sterilization and waste disposal

121°C (250 F) for 15 mins

Autoclave is used to sterilize liquid media, instruments, glassware at?

132°C (270 F) for 30 to 60 minutes

Autoclave is used to sterilize infectious medical waste @

3 days

Fractional is autoclaved for __

Fractional

Alternate heating (kills vegetative cells),
incubation (spores germinate), and heating
again (kills remaining vegetative cells and
spores)

100°C for 30 minutes for 3 successive days

75°C-80°C for 2 hrs for 3 successive days

a. Tyndallization
- Flowing steam, _____

b. Inspissation
- ____

-Used for culture media with
increased proteins (L-J, Loeffler's) - used
for MTB culture

Flame

used for sterilizing wire loops and inoculating

Bacillus subtilis var. niger

Oven Quality control: spores of ?

Oven

160°C-180°C for 1 ½ to 3 hrs

used for sterilizing glassware, certain metals, oils, petrolatum, or powders, for _____?

Incineration

Most common method of treating infectious waste

870°C-980°C

Hazardoes materials are literally burned to ashes in incineration at ?

Cremation

used for controlling diseases

Filtration

Method of choice for antibiotic solutions, toxic
chemicals, radioisotopes, vaccines, and
carbohydrates, which are all heat sensitive

Bacillus pumilus

Ionizing Radiation- Quality control: _____

Ionizing radiation

 Plastic syringes, catheter, or gloves
 Short wavelength, high energy gamma rays

• Ethylene glycol

• Formaldehyde Vapor and Vapor Phase hydrogen peroxide

• Glutaraldehyde

• Peracetic aicd

Cheminal methods:

Bacillus subtilis var globitii

Ethylene glycol- Quality control: _____

Ethylene glycol

Most common chemical sterilant

Formaldehyde Vapor and Vapor Phase Hydrogen
Peroxide

Chemical that sterilize HEPA Filters in BSCs

Glutaraldehyde

 Sporicidal (Kills spores) in 3-10hrs
 Used for bronchoscopes, because it does not
corrode lenses, metal, rubbers

Peracetic acid

 Effective in the presence of organic material
 Also used for the surface sterilization of surgical instruments
 Cold sterilization

Disinfection (Anti-sepsis)

is a process whereby organisms, but not necessarily all microorganisms or spored, are destroyed.

Only pathogenic organisms are killed

• Boiling

• Pasteurization

• Non-Ionizing Radiation

Physical Method for Disinfection

Pasteurization

Used mostly in the food industry, eliminated food-borne pathogens and organisms responsible for food spoilage

Pasteurization

Main advantage: Treatment at this temperature reduces spoilage of foods without affecting its taste;

Disadvantage: Endospores survive

63°C for 30 minutes

72°C for 15 seconds

Batch method:__

Flash method:__

• Alcohol

• Aldehydes

• Halogens

• Heavy metals

• Quaternary Ammonium Compound

• Phenolics

• 
  

Chemical methods on Disinfection

antiseptics

disinfectants used on living tissue are called

Alcohol

is non-sporicidal and evaporates quickly

its use is limited to the skin as an antiseptic or on thermometers and injection vial rubber septa as disinfectant

50% ethanol or 10 sodium hypochlorite

Open wounds: use _______

70% ethyl alcohol

iodophor

__, followed by an_, is
the most common compound used for skin
disinfection before drawing blood specimen for
culture or surgery

1% silver nitrate

Eye-drop solution containing _______
is still placed in the eyes of newborn to prevent
infection with N. gonorrhoeae

Quaternary Ammonium Compound

Used to disinfect bench tops, or other surfaces
in the laboratory

Phenol

Gold standard disinfectant

Laminar Flow Biosafety Cabinet

Class II BSC is also known as?

Biosafety Level 1

have no known potential for infecting healthy
people

Biosafety Level 2

common clinical pathogens in blood and body
fluids