Week 1-BACTE INTRO Flashcards
Wrote a treatise on the germ theory of disease
entitled “de Contagione”
Girolamo Fracastoro or Hieronymous Fracastorius
Made key observations on microscopic organisms
Robert Hooke
the ability of bacteria, such as the
Mycobacterium spp., to retain dye when treated with
mineral acid or acid-alcohol solution
Acid-fastness
microorganisms that grows
best in the absence of oxygen (O2) but can toerate low
concentrations of oxygen (O2)
Aerotolerant anaerobes
organisms that produce organic
compounds from carbon dioxide as a carbon source
Autotrophs
Infectious waste should be placed into two leak-
proof, plastic bags for sturdiness; this is known as
double-bagging
Air that contains the infectious material is sterilized,
either by heat, UV light, most commonly by passage
through a
HEPA filter
Dry heat
Requires longer exposure times
(1.5 to 3 hours) and higher
temperatures than moist heat
(160°C to 180°C)
It is the method of choice for
antibiotic solutions, toxic
chemicals, radioisotopes,
vaccines, and carbohydrates,
which are all heat sensitive.
Filtration
used in
microwaves and radiograph
machines are short wavelength
and high-energy gamma rays.
Used for sterilizing disposables
such as plastic syringes,
catheters, or gloves before use.
Ionizing (gamma) radiation
Most common sterilant is_____
which is used in gaseous form for sterilizing heat-
sensitive objects.
Ethylene Oxide (EtO),
____and ____have been used to
sterilize HEPA filters in BSCs.
Formaldehyde capor and capor-phase hydrogen
peroxide (oxidizing agent)
is sporicidal in 3 to 10
hours, is used for medical equipments such as
bronchoscopes, because it does not corrode
lenses, metal, or rubber.
Glutaraldehyde
The use of peracetic acid or glutaraldehyde is
called
Cold sterilization
CHEMICAL DISINFECTANTS
Phenolics
Aldehyde
Halogen (Iodine, Chlorine)
Alcohol (Ethanol, Isopropanol)
Heavy Metals
Quaternary ammonium compounds
Includes information on the nature of the chemical,
the precautions to take if the chemical is spilled, the
disposal recommendations.
Manufacturer’s Material Safety Data Sheet (MSDS)
_____are provided in the laboratory to prevent
inhalation of toxic fumes.
Fume hoods
FIVE MOST FREQUENTLY ACQUIRED LABORATORY
INFECTIONS
Shigellosis
Salmonellosis
Tuberculosis
Brucellosis
Hepatitis
Allow room (unsterilized) air to
pass into the cabinet and around
the area and material within,
sterilizing only the air to be
exhausted.
They have negative pressure,
are ventilated to the outside, and
are usually operated with an
open front.
Class I cabinets
Sterilize air that flows over the
infectious material, as well as air
to be exhausted.
The air flows in “sheets” which
serve as barriers to particles
from outside the cabinet and
direct the flow of contaminated
air into the filters; thus, called
vertical laminar flow BSCs.
Class II cabinets
is self-
contained, and 70% of the
air is recirculated; mostly
used in hospital clinical
microbiology laboratory
Type A (Class IIA)
exhaust
air is discharged outside the
building; is selected for
radioisotopes, toxic
chemicals, or carcinogens
will be used.
Type B (Class IIB)
Offer the most protection to the
worker because they are
completely closed and have
negative pressure.
Air coming into and going out of
the cabinet is filter sterilized, and
the infectious material within is
handled with rubber gloves that
are attached and sealed to the
cabinet.
It is important to the proper
operation of laminar flow
cabinets that an open area for 3
feet from the cabinet be
maintained during operation of
the air-circulating system; this
ensures that infectious material
is directed through the HEPA
filters.
Class III cabinet
CLASSES OF BIOLOGICAL SAFETY CABINETS
Class I CABINET
CLASS II CABINETS
CLASS III CABINETS
