Transcript Microbiology Chapter 15 part 2

Microbiology Chapter 15 part 2
Practical Applications of Immunology
I. Vaccines
a. Substances that contain antigens to stimulate the
immune system to produce antibodies specific for
those antigens
b. Artificial acquired immunity
c. Principles and Effects of Vaccination
i. The injection produces the primary response of the
immune system leading to the formation of antibodies
and long term memory cells
ii. If a second exposure is encountered the memory
cells are stimulated producing a rapid response
(second response is quick and more intense than
primary)
Microbiology Chapter 15 part 2
d. Types of Vaccines
i. Attenuated whole agent vaccines: living, but
weakened
1. more closely mimic an actual infection
2. lifelong immunity accomplished with boosters
3. Ex: MMR
4. Danger: live microbes can back mutate to
virulent forms
ii. Inactivated whole agent vaccine: Microbes have
been killed. Ex: rabies, influenza, polio
Microbiology Chapter 15 part 2
iii. Toxoids: inactivated toxins that are no
longer toxic but retain antigenic character
that stimulates antibodiy response
1. Tetanus and Diphtheria
2. require boosters every 10 years
iv. Subunit vaccines: Use only an antigenic
fragment of a microbe that best stimulate
an immune response
1. Recombinant vaccines: produced by genetic
engineering tech. (hep B)
2. inherently safer because can’t reproduce in
the recipient and contain little or no extraneous
material that can produce side effects; also,
separate fractions of the disrupted bacterial cell
and retain and use only the fraction desired
(ex:acellular vaccine for pertussis)
Microbiology Chapter 15 part 2
v. Conjugated vaccines: help deal with poor immune
response in young children to vaccines based on
capsular antigens (polysacch)
vi. Nucleic acid vaccines: DNA vaccines: actually
inject plasmids of naked DNA into muscles to get
production of proteins encoded in DNA (scary?)
OH DEER
15.
19
Fig. 15.20
Microbiology Chapter 15 part 2
II. Immunological Tests
A. Serology: based on blood serum tests to detect and
quantify antigens and antibodies found in serum samples
B. Precipitin Test (precipitate) – precipitation reactions
between soluble antigens and antibodies, when the meet
they form a visible precipitate (tube – precipitin ring test,
or plate – gel immunodiffusion ) pgs. 523
i. Can be used to determine the presence of
more than one antigen in a serum sample
ii. We will do one as an example in lab
Microbiology Chapter 15 part 2
C. Agglutination Reactions (Clumping) pg. ______
i. Particulate antigens (particles like cells, or artificial
particles made in the lab with latex beads)
ii. Antigen Antibody reaction produces a distinct clumping
as the Antigens and Antibodies react to link together
and produce large easily seen clumps.
1. used to quantify the amount of antibody against an
antigen (is it increasing? - antibody titer)
2. Hemagglutination reactions: clumping of RBC:
blood typing - ABO blood groups
16.9
16.10
Fig.
16.11
Microbiology Chapter 15 part 2
D. Neutralization Reactions
i. Neutralization: antigen-antibody reaction in
which harmful effects of bacterial
exotoxins or a virus are blocked by
specific antibodies
ii. Can be used a s diagnostic test to identify
viruses and ascertain viral antibody titer
Microbiology Chapter 15 part 2
E. Tagged antibody tests
i. Immunofluorescence: uses antibodies that
fluorescent dye has been attached to, glow with green
or orange color when exposed to UV light pg 516,
526, fig 17.4, fig 17.15
ii. Radio immunoassay: Uses a radioactive marker on
the Antigen or antibody, and the amount of radiation is
measured in the end; used to determine tiny amounts
of antigen or antibody (problem these days of
disposing of radioactive material)
Fig. 17.15
Fig.
17.4
Microbiology Chapter 15 part 2
• iii. ELISA (Enzyme Linked Immunosorbent
Assay) very important, sometimes called EIA.
• Review your notes from last chapter and be
sure you can illustrate for the test. See page
528, fig. 17.16 in text.
Fig.
17.16
Microbiology Chapter 15 part 2
*****WESTERN BLOT TEST – CONFIRMATORY
TEST FOR HIV – DETECT SPECIFIC HIV
PROTEINS – fig 17.13, pg 524
Fig.
17.13