Microbiology Exam #3 - TERMS

variolation

inoculation of smallpox (Variola virus) into the skin

vaccine

provokes a primary immune response leading to the formation of antibodies and memory cells

herd immunity

immunity in most of the population due to vaccinations

live attenuated vaccines

weakened, live version of the pathogen to trigger an immune response without causing disease

inactivated killed vaccines

type of vaccine that contains pathogens that have been killed or inactivated; stimulate the immune system to produce antibodies against the pathogen

subunit vaccines

use antigenic fragments to stimulate an immune response and produce antibodies and memory cells

recombinant vaccines

lab made vaccines that are created by taking a small piece of DNA and inserting it into a manufactured bacterial or yeast cell to trigger and immune response

virus-like particle vaccines

resemble intact viruses but do not contain viral genetic material

conjugated vaccines

type of subunit vaccines where antigens are linked to polysaccharides

nucleic acid (DNA) vaccines

injected naked DNA that produces the protein antigen encoded in the DNA; protein antigens carried to the red bone marrow stimulate humoral and cellular immunity

toxoids

modified bacterial toxins used in vaccines to stimulate an immune response without causing disease

adjuvants

chemical additives added to vaccines to improve the innate immune response

sensitivity (true positive rate)

probability that a test is reactive if the specimen is a true positive

specificity (true negative rate)

probability that a test will NOT be reactive is a specimen is a true negative

hybridoma

“immortal” cancerous B cell (myeloma) combined with an antibody-producing normal B cell; produces monoclonal antibodies

monoclonal antibodies

man-made proteins designed to mimic the function of natural antibodies in the body

precipitation reactions

type of antigen-antibody reaction where soluble antigens and antibodies combine to form an insoluble complex (precipitate); help identify and quantify the presence of specific antigens or antibodies

precipitin ring test

detect the presence of antigen-antibody complexes; cloudy line forms where there is the optimal ratio of antigen and antibody

immunodiffusion test (ouchterlony)

precipitation reaction carried out in an agar gel medium; precipitate develops at the point where the optimal antigen-antibody ratio occurs

immunoelectrophoresis

combines electrophoresis with immunodiffusion; separates proteins in human serum to identify and characterize them, particularly antibodies

agglutination reactions

when RBCs clump together in a liquid due to the binding of antibodies to specific antigens on the surface of those particles

direct agglutination tests

detect antibodies against large cellular antigens; measure concentration of serum antibody (titer) ——> rise in titer indicates a greater immunity to disease

seroconversion

the production of antibodies in the blood of a person who did not have the antibodies before

indirect (passive) agglutination tests

inert particles coated with antigens to detect specific antibodies in a sample

hemagglutination

agglutination of RBC surface antigens and complementary antibodies; used in blood typing

viral hemagglutination

the linking together of the red blood cells by the viral particles resulting in clumping; detects the presence of viral particles

neutralization reactions

antigen-antibody reaction where the harmful effects of an exotoxin or a virus are blocked by antibodies to the toxin

viral hemagglutination inhibition test

used to determine the concentration of antibody response to a viral infection

direct fluorescent-antibody test

uses a fluorescently labeled antibody to directly bind to a TARGET antigen making it visible under a fluorescence microscope

indirect fluorescent-antibody test

fluorescent-antibody test to detect the presence of specific antibodies

antihuman immune serum globulin

an antibody added to an FA test that reacts specifically with human antibodies if the result is positive

fluorescence activated cell sorter

counts and sorts cells labeled with the fluorescent antibodies; detector determines size and fluorescence

ELISA

a group of serological tests that use enzyme reactions as indicators

direct ELISA

uses only ONE antibody to detect antigens

indirect ELISA

uses TWO antibodies to detect antigens

western blotting (protein immunoblotting)

analytical technique used to identify and locate specific proteins via electrophoresis and a blotter based on their ability to bind to specific antibodies

selective toxicity

selectively finding and destroying pathogens without damaging the host

chemotherapy

the use of chemicals to treat a disease a disease

antibiotic

a substance produced by a microbe that, in small amounts, inhibits another microbe

antimicrobial drugs

synthetic substances that interfere with the growth of microbes

narrow spectrum of microbial activity

drugs that affect a narrow range of microbial types

broad-spectrum antibiotics

affect a broad range of gram-positive or gram-negative bacteria

superinfection

overgrowth of normal microbiota that is resistant to antibiotics

bactericidal

kill microbes directly

bacteriostatic

prevent microbes from growing

interferons

produced by viral-infected cells to inhibit further spread of the infection

disk-diffusion method (kirby-bauer test)

tests the effectiveness of chemotherapeutic agents

zone of inhibition

the area of no bacterial growth around an antimicrobial agent in the disk-diffusion/kirby-bauer method

epsilometer test (e test)

agar diffusion test to determine antibiotic sensitivity using a plastic strip with varying concentrations of an antibiotic

persister cells

microbes with genetic characteristics allowing for their survival when exposed to an antibiotic

superbugs

bacteria that are resistant to large numbers of antibiotics

synergism

the effect of two drugs together is GREATER than the effect of either alone

antagonism

the effect of two drugs together is LESS than the effect of either alone