Disease definitions Flashcards
Infection
Infection is the invasion of a host organism’s body tissues by disease-causing agents
Infectivity
Refers to the ability of a pathogen to establish an infection
Virulence
The degree of pathogenicity within a group or species of parasites as indicated by case fatality rates
Pathogenicity
Refers to the ability of an organism to cause disease and cause harm to the host
Incubation period
The time from the moment of exposure to an infectious agent until signs and symptoms of the disease appear
Prokaryote
A single celled organism that has no nuclear membrane and no organelles in the cytoplasm except ribosomes
Bacteria shapes
Cocci - circular
Bacilli - rod shaped
Spirilli - spiral
Endospores
An endospore is a dormant, tough, non-reproductive structure produced by a small number of bacteria. The primary function is to ensure survival of bacteria through periods of environmental stress
Plasmids
A plasmid is a small, circular, double-stranded DNA molecule that is distinct from a cell’s chromosomal DNA. Plasmids naturally exist in bacterial cells
The process of conjugation
Bacterial conjugation is the transfer of genetic material (plasmid) between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells.
Antibiotics
They act by killing or inhibiting the growth of bacteria.
The germ theory
States that some diseases are caused by microorganisms within the body
Epidemiology
Is the science that studies the patterns, causes and effects of health and disease conditions in defined populations.
Gram positive versus gram negative
Gram positive - bacteria with thick cell wall retains crystal violet stain, PURPLE
Gram negative - bacteria that do not retain the crystal violet stain, PINK
