Definitions (Dustin) Flashcards
Transport Medium
medium for transporting clinical specimens to the lab for examination. Able to keep the organism for 48 hours
Pathogenicity
Ability of a microbe to cause disease in the host
Virulence
Degree of damage caused by pathogen. Objective, quantitative measurement of pathogenicity. Can be measured by LD50 titer.
Endotoxin
Generally refers to phospholipid-polysaccaride components of cell wall in gram negative bacteria. Lipid-A of LPS -> endotoxin. Generally more heat stable, less specific, and less potent than exotoxins.
Active immunization
Giving live or killed infection agents or their antigens -> host actively produces antibodies, lymph cells able to respond to antigen
Passive immunization
Giving ready-made antibodies, for example when the patient is already ill.
Agglutination
Antigen-antibody rxn ends up in visible sedimentation of Ag-Ab complex. May be used in serotyping.
Antibody titer
Lowest concentration (highest rate of dilution) of antibodies at which the given rxn still gives a visible result
Resident vs transient microbial flora
pretty self explanatory. transient are only there temporarily
Vaccine
Any preparation used for active immunological preventive treatment. Often from killed or attenuated microbes of virulent strains
Toxoid
An exotoxin detoxicated by heat or formaldehyde. Can provoke an immuno response, but it’s non-toxic. E.g. the vaccine for diptheria and tetanus
Attenuation
Selecting mutant, not virulent strains of a microbe. These are alive, but harmless microbes. Can provoke immuno response, so can be used for vaccination. E.g. BCG vaccine contains attenuated mycobacterium bovis (for tuberculosis)
Agglutinin
An antibody that causes clumping or agglutination of bacteria or other cells
Co-agglutination
A passive agglutination test in which specific antibody is in vitro bound to surface of S. aureus cells. The bound antibodies cause agglutination if the homolog antigen is added. The antibodies (or antigens) can be bound to latex instead, then it’s latex agglutination.
Precipitin
An antibody that under suitable conditions crosslinks with its specific, soluble antigen and causes precipitation
O antigen
Somatic antigen of enteric gram-negative bacteria. External part of cell wall liposaccharide
H antigen
flagella. highly antigenic part of enteric gram-neg bacteria
Capsule Antigen
capusle of bacteria is highly antigenic. In enteric bacteria it is called the K antigen
Protective antigen
Antigen responsible for protective immunity, so we can use it for vaccination
Bacteriolysis
Dissolution of bacteria. For example, using hypotonic solution or a specific antibody and complement that destroys the bacterial membrane
Epidemy
Infections occuring as part of an outbreak of infection. Defined as a significant increase in the usual rate of infection.
Endemy
A disease which happens in relatively low numbers, but continuously in a specific community.