Exam 1 Review Flashcards
(95 cards)
Cellular, living microorganisms such as bacteria, archaea, fungi, protists, and helminths.
Microorganisms
A pathogen that does not require a weakened host to cause disease.
True Pathogen
Pathogens that only cause disease when their host, is weakened in some way.
Opportunistic Pathogens
Four principles that establish the criteria for determining the causative agent of an infectious disease:
- ) The same organism must be present in every case of the disease.
- ) The organism must be isolated from the diseased host and frown as pure culture.
- ) The isolated organism should cause the disease in question when it is introduced into a susceptible host.
- ) The organism must then be re-isolated from the inoculated, diseased animal.
Koch’s Postulate of Disease
Also known as nosocomial infections; an infection that a patient develops while receiving care in a healthcare setting.
Health acquired infection, HAI
Germ free practices; term applied to techniques designed to prevent the introduction of contaminating microbes to a patient, a clinical sample, or others in the healthcare setting; methods that present healthcare- acquired infections by preventing the introduction of potentially dangerous microbes.
Aseptic Technique
States that microbes cause infectious diseases.
Germ theory of disease
Normal human flora, including bacteria, archaea, and eukaryotic microbes.
Normal Microbiota
A type of symbiotic relationship that has no perceived benefit or cost to them.
Commensalism
A type of symbiotic relationship that hurts the host.
Parasitism
A type of symbiotic relationship that helps the host.
Mutualistic
A term describing the general ability of an infectious agent to cause disease.
Pathogenic
Sticky microbial communities made up of single or diverse species; they allow microbes to coordinate responses with an environment.
Biofilms
Differential staining procedure that distinguishes between cells with and without waxy mycolic acid cell walls; mycobacterium tuberculosis and mycobacterium leprae are examples of clinically important acid-fast bacteria.
Acid Fast Stain
A staining procedure that allowed us to classify bacteria as either Gram-positive or Gram-negative; Following the gram staining procedure gram positive cells appear purple while gram negative appear pink. The final outcome of the gram stain is based on the cell wall properties of the stained cells.
Gram stain
Is a differential stain used to visualize bacterial endospores. Endospores are formed by a few genera of bacteria, such as Bacillus. By forming spores, bacteria can survive in hostile conditions. Spores are resistant to heat, desiccation, chemicals, and radiation.
Spore stain
Staining techniques that use just one dye; typically only size, shape, and cellular arrangement can be determined using simple stains.
Simple Stain
Includes the prokaryotes people encounter on an everyday basis. Most bacterial species are heterotrophic; that is, they acquire their food from organic matter. The largest number of bacteria are saprobic, meaning that they feed on dead or decaying organic matter.
Domain Bacteria
Organisms that are all unicellular and lack a membrane bound nucleus. They also lack other membrane bound organelles, and have a much simpler genetic makeup that eukaryotic cells. Bacteria and archaea are prokaryotes.
Prokaryotic Cells
The three basic bacterial shapes are coccus (spherical), bacillus (rod-shaped), and spiral (twisted), however pleomorphic bacteria can assume several shapes. Cocci (or coccus for a single cell) are round cells, sometimes slightly flattened when they are adjacent to one another.
Shape or arrangement of a prokaryote
Cells appear pink, thin layer of peptoglygican
Gram negative
Cells appear purple thick layer of peptoglycigan
Gram Positive
Bacteria (also known as acid-fast bacilli or AFB) are microorganisms resistant to decolorization by an acid, hence, the term acid-fast. Acid fastness is a unique characteristic of M. tuberculosis. However, other mycobacterial species may exhibit the same feature.
Acid Fast Mycolic acid
A term that describes cells with a single flagellum.
Monotrichous Flagella