quiz 2-25-15 Flashcards
what is the study of how a specific infectious agent survives and spreads through a community
epidemiology
what is the actual way the infectious agent is spread?
Disease transmission
what is the entrance way through which a specific microbe is able to invade a host
portal of entry
what are the 2 most common portals of entry
respiratory tract and GI tract
person to person form of transferring microbes is known as
direct transmission
any object living or non-living that allows a microbe to grow , reproduce and maintain its ability to remain infective is
reservoir of infection
a non-living object capable o allowing a microbe to survive but not reproduce is known as a
fomite
an inanimate object that can serve as vehicle for the spread of disease
fomite
what can control fomite transmission?
hand washing
what is the single most important method of controlling microbes in a clinical setting
hand washing
what is the goal of isolating bacteria?
to obtain a pure culture
what are pure cultures used forq
to carry out biochemical testing to determine abt sensitivity to develop vaccines determining the nutritional requirements study organisms that cause disease
agar is a substance derived from
seaweed
agar melts at what degrees
100 degrees C
agar solidifies at
42 degrees C
agar remains liquid at
45 degrees C
what is the solid surface to grow isolated colonies of bacteria
agar
what is a colony
a clump of bacteria growing on a solid surface
true or false
every cell in the colony is genetically identical
true
what are the usual temperatures used in a laboratory propagation?
it falls between 20C and 40C
a container of medium, that grows only a single known species or type of microorganism is called
a pure culture
what is frequently used to allow the precise examination and control of one microorganism by itself
a pure culture ( axenis )
a water based solution that do not solidify at temperatures above freezing and that tend to flow freely when the container is tilted is what kind of media
liquid media that comes in broth, milk or infusion.
what form of media exhibits a clot like consistency, used to determine the motility of bacteria
semi-solid media
what type of media provides a firm surface on which cells can form discrete colonies and are advantages for isolating and culturing bacteria and fungi
solid media
what type of media can viruses grow
none. viruses can only be cultivated in live host cells not media
what are the two types of solid media
liquefiable solid media and non-liquefiable solid media
name a general purpose media type
tryptic soy
tryptic soy broth
brain heart infusion
what are bacteria that require growth factors and complex nutrients are termed
fastidious
how is media made
powder is mixed with distilled water, the media liquid is dispensed into tubes or bottles and its then autoclaved to be sterilized
an autoclave reaches what tempurature
121 degrees C
an autoclave reaches what PSI
15 pounds of PSI
how long is media placed in the autoclave?
20 minutes kills all bacteria, fungi, spores and viruses