bact classification and identification Flashcards
what is taxonomy
science that studies organisms in order to arrange them into groups
what is identification
characterizing organism
what is classification
arranging organisms into similar or related groups
what is nomenclature?
assigning names to organisms
define phenotype
specific characteristics displayed by the organism
define genotype
genetic info contained in the DNA
define evulation
change in a line of descent over time leading to a new species
what is phylogeny
study of evolutionary relationship
which rRNA is used for bacteria?
16S rRNA
which rRNA is used for fungi?
18S rRNA
what are firmicutes?
- gram positive
- low GC content
- mycoplasma (no cell wall) : MOLLICUTES
what are actinobacteria?
- gram positive
- high GC content
what are proteobacteria/
- gram neg
- aerobic or facultative
what are bacteriodetes?
- gram negative
- anaerobic
what is the order of hierarchy?
- domain
- phylum
- class
- order
- family
- genus
- species
what are clones
population of cells derived from a single parent cell
what are strains
an isolate
what are species
a group of related isolates
what are subspecies
strains within a species with some important characteristics
what are the two mediums for growing bacteria?
- broth
- solid (agar)
what are the two types of dyes added to colorless bacteria?
acidic or basic
what charge do bacteria naturally carry?
negative charge - so you use basic dyes more often
what are some basic dyes
crystal violet, methylene blue, malachite green, safranin
what are the three staining techniques
simple, differential, special
what is simple staining
methylene blue, carbol fuchsin, crystal violet, safranin
what is differential staining
gram stain and acid-fast
what is special staining
stain specific structures
what does acid-fast staining diagnose?
mycobacterial infections
describe capsules when staining
difficult to stain, hence the background is stained
describe spores when staining
requires to heat to make the stains penetrate the thick spore coat
describe flagella when staining
too thin, hence the procedure used increases the thickness of the flagella
how do you detect enzymes produced?
substrates utilized and products produced
what is serology
the study of antigen-antibody reactions
how do serology tests work?
they test to detect surface antigens (proteins or polysaccharides) of bacteria using antibodies
what are some examples of serological tests
- neutralization
- precipitation
- agglutination
- western blot
what is precipitation
interaction of soluble antigen with an antibody
what is agglutination?
interaction of particulate antigen with antibody
what is passive agglutination
soluble antigen or antibody coated or linked to cells or insoluble particles such as latex,
what is western blot used for
identify specific antibodies
-proteins separated by electrophoresis
what two dyes are used in fluorescent antibody technique?
- rhomamine: red
- fluorescein isothyocynate: yellow-green
-Ab are linked to the dye
what is PCR
identification of cultivable and uncultivable bacteria
-allows amplification of a piece of DNA or RNA
what are the three steps in PCR indentification
- denaturation: separation of strands at 95 C
- annealing: binding of primers at 50 C
- elongation: synthesis of complementary
what is RT-PCR
- real time: immediate visual result
- fluorescent labeled primers
- quantitative
what is categorization of strains within a species?
typing
what is biochemical typing?
biotypes vs biovars
what is serological typing?
- serotypes vs serovars
- based on antigens
what is genetic typing?
based on genetic variation
-genotypes
what is virotyping
based on virulence factors
-called pathotypes
what is page typing
-based on phage susceptibility
what is bacteriocin typing
based on bacteriocin susceptibility
what is antibiogram typing
based on antimicrobial susceptibility
