Biosafety levels BSL - answer✔BSL1-few safety controls open lab bench non pathogenic
organisms
BSL2-open bench gloves lab coat eye protection required-moderate pathogens
BSL3-designed for pathogens; organisms manipulated in biological safety cabinets room under
neg pressure filtration of air
BSL4-life threatening pathogens transmitted by aerosols, pressurized suits for workers-ebola
the common sources to obtain clinical specimens - answer✔1. blood-look for bactermia or
viremia-bacteria in blood presence of antibodies to pathogen
2. urine-bacteriuria bacteria in urine, urinanalysis dip stick growth dependent
3. feces-intestinal pathogens
4. abscesses and wounds-swab
5. throat/nasal swabs
6. genital samples-sexually transmitted pathogens
growth dependent identification - answer✔clinical specimens used to obtain pure cultures of
bacteria
selective vs differential medium - answer✔selective-contains substances that inhibit growth of
certain types of bacteria
Differential-compounds that allows visualization of certain biochemical pathways and products
ways to test sensitivity to antibiotics - answer✔test sensitivity to drug best used to treat
pathogen
testing methods
1. minimum inhibitory concentration (mic) tube dilution assay-the clear tubes
2. disk diffusion assay-pure culture on plate disks containing antibiotcs are placed on plate
comes up with clear lawn around it the clear spot in the cloudy area. aka kirby bauer test
3. Etest-MIC is read from edge of clear zone using the scale on strips
antigen-antibody immunoassay reactions - answer✔highly specific recognition of an antibody
for its related antigen
allows for diagnostic-detection of antigens in blood, urine, serum means you have pathogen
same with if you find antibodies you have pathogen
antibody and antigen definitions - answer✔antibody-blood protein produced in response to
antigen, combines with toxin/foreign substance
antigen-a toxin which induces immune response-antibodys
epitopes - answer✔where antibody attaches itself-epitopes are on antigens
reaction is specific due to antibodies recognizing and binding to epitopes on proteins
serology - answer✔serology:is the use of antigen-antibody reactions to detect antigens and
antibodies
serotype: identification of a pathogen using antigens on its external surface!
identify serotypes
serotypes are the different kinds of antigens to identify strains identified by host range,
virulence factors, and symptoms
done by using antibodies for genetic analysis by PCR or fingerprinting
E.coli serotypes
Influenza serotypes
3. example - answer✔E.coli
antigens-LPS(O) and flagella(H)
naming-O#H#
example-O157H7
Influenza
antigens-hemaglutinin(H) and neuraminidase(N)
naming-H#N#
example-H1N1
antibody titer - answer✔lowerst concentration of serum at which an antibody antigen reaction
is observed
mantoux skin test - answer✔common for testing of previous exposure or current infection with
mycobacterium tuberculosis
inject MT antigen into body if swollen then you have latent infection
Agglutination - answer✔soluble antibodies cause clumping of antigens that are on the surface
of synthetic particle or cell
ex: agglutination of blood cells in blood typing (hemagglutination)
staph aureus
antibodies bind blood cell
produce cisible clumping and aggregation
immunofluorescence - answer✔uses specific antibodies that are chemically linked to
fluorescent molecules to detect pathogen
2. Indirect-antibodies can also be made that recognize antibodies from another host. antirabbit
antibodies purified and labeled w/fluorescent-increases sensitivity of detection
Enzyme immunosorbent assays EIA or ELISA - answer✔enzymes chemically attached to purified
antibodies-produce colored product
1. direct- immunoassays use immobilized antibody to test for an antigen from the patient
2. indirect-use immobilized antigen to detect antibodies from a patient
PCR to detect pathogens - answer✔one of the most powerful diagnostic tools
does patient sample contain DNA of a specific pathogen
PCR product is made if PCR primer sequences exactly base pair with pathogen DNA
1. template
2. primers bind to template
qPCR quantitative real time PCR - answer✔diagnostic PCR products can be detected by this
requires thermocycler
a fluorescent probe-fluorescence increases as double stranded DNA product is made
binds DNA product
the line that is closest as has less amplification cycles has more E.coli
types of genome alterations - answer✔genome rearrangements
mobile genetic elements (plasmids)
phage integrations
pathogenecity islands
all alterations associated with increased antibiotic resistance
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