Micro20 exam3 ELAC

Term Definition
acute Characterized by rapid onset and short duration.
asepsis A condition free of viable pathogenic microorganisms.
Prevelence The total number of cases of a disease in a certain area and time period.
Incidence In epidemiology, the number of new cases of a disease occurring during a period.
Etiology the cause or causes of a disease or abnormal condition
Pathogenicity The capacity of microbes to
cause disease.
Virulence In infection, the relative capacity of a pathogen to invade and harm host cells.
Normal Flora Beneficial or harmless resident bacteria commonly found on and/or in the human body.
Infection The entry, establishment, and
multiplication of pathogenic organisms
within a host.
Disease Any deviation from health, as when the effects of microbial infection damage or disrupt tissues and organs.
Adherence the “active, voluntary, and collaborative involvement of the patient in a mutually acceptable course of behavior to produce a therapeutic result.
Phagocytosis A type of endocytosis in which
the cell membrane actively engulfs large
particles or cells into vesicles.
Collagenase which digests the principal fiber of connective tissue and is an invasive factor of Clostridium species and certain worms
hyaluronidase which digests hyaluronic acid, the ground
substance that cements animal cells together. This enzyme is an important virulence factor in staphylococci, clostridia, streptococci, and pneumococci.
Lecithinase any of several enzymes that hydrolyze lecithins
coagulase A plasma-clotting enzyme secreted by Staphylococcus aureus. It contributes to virulence and is involved in forming a fibrin wall that surrounds staphylococcal lesions.
kinases dissolving fibrin clots and expediting the invasion of damaged tissues.
Leukocidin A heat-labile substance formed
by some pyogenic cocci that impairs and
sometimes lyses leukocytes.
Hemolysin Any biological agent that is capable of destroying red blood cells and causing the release of hemoglobin. Many bacterial pathogens produce exotoxins that act as hemolysins.
Hemolysis lysis of red blood cells with liberation of hemoglobin
alpha hemolysis a greenish discoloration and partial hemolysis of the red blood cells immediately surrounding colonies of some streptococci on blood agar plates
beta hemolysis a sharply defined clear colorless zone of hemolysis surrounding colonies of certain streptococci on blood agar plates
gamma hemolysis If an organism does not induce hemolysis, the agar under and around the colony is unchanged, and the organism is called non-hemolytic or said to display gamma hemolysis (?-hemolysis). Enterococcus faecalis displays gamma hemolysis.
Exotoxin exotoxin A toxin (usually protein) that is secreted and acts upon a specific cellular target. Examples: botulin, tetanospasmin, diphtheria toxin, and erythrogenic toxin.
Endotoxin a toxin of internal origin; specifically : a poisonous substance present in bacteria (as the causative agent of typhoid fever) but separable from the cell body only on its disintegration
Toxoid A toxin that has been rendered nontoxic but is still capable of eliciting the formation of protective antitoxin antibodies; used in vaccines.
Adhesions the abnormal union of surfaces normally separate by the formation of new fibrous tissue resulting from an inflammatory process
Koch’s postulates procedure 2 establish specific cause of disease. all cases of infection: 1.agent must be found 2.inoculations of pure culture must reproduce same disease in animals 3.agent must again be present in experimental animal 4.pure culture must again be obtained
Chain of infection way of gathering info needed to interrupt or prevent epidemic. links in chain must be favorable to the organism for epidemic to continue. Breaking any link in chain can disrupt epidemic. Which link is most effective to target will depend on organism.
Resident flora Resident flora is also referred to as microflora, indigenous flora, or microbiota. These flora are those that regularly colonize in the body. One such flora is yeast, found in women.
Zoonosis An infectious disease indigenous to animals that humans can acquire through direct or indirect contact with infected animals.
Portal of exit is usually the same as the portal of entry, but some pathogens use a different route
Transmission of pathogens – Escape from the host or reservoir of infection (where the infectious agent normally lives and multiplies).
– Transport to the new host.
– Entry to the new host.
– Escape from the new host.
Fomite Virtually any inanimate object an infected individual has contact with that can serve as a vehicle for the spread of disease.
Common vehicle is a single material that serves as the source of infection for many individuals. Some specific types of vehicles are food, water, various biological products (such as blood, serum, and tissue), and fomites.
Vector An animal that transmits infectious agents from one host to another, usually
a biting or piercing arthropod like the
tick, mosquito, or fly.
Nosocomial An infection not present upon admission to a hospital but incurred while being treated there.
Portal of entry area in which a microorganism enters the body. They may be cuts, lesions, injection sites, or natural body orifices.
Infection The entry, establishment, and
multiplication of pathogenic organisms
within a host.
Infectious dosage is the amount of pathogen (measured in number of microorganisms) required to cause an infection in the host.
Usually it varies according to the pathogenic agent and the consumer's age and overall health.
Carrier A person who harbors infections and inconspicuously spreads them to others. Also, a chemical agent that can accept
an atom, chemical radical, or subatomic particle from one compound and pass it on to another.
Opportunists bacterium, virus, protozoan or fungus that takes advantage of certain opportunities to cause disease. Those opportunities are called opportunistic conditions.
true pathogens are capable of causing disease in healthy persons with normal immune defenses ex. influenza virus, plague bacillus, and ect
chronic Any process or disease that persists over a long duration.
acute Characterized by rapid onset and short duration.
sporadic Description of a disease that exhibits new cases at irregular intervals in unpredictable geographic locales.
endemic A native disease that prevails continuously in a geographic region.
epidemic A sudden and simultaneous outbreak or increase in the number of cases of disease in a community.
pandemic A disease afflicting an increased proportion of the population over a wide geographic area (often worldwide).
lesion A wound, injury, or some other pathologic change in tissues.
abscess An inflamed, fibrous lesion enclosing a core of pus.
pus thick opaque usually yellowish white fluid matter formed by suppuration and composed of exudate containing leukocytes, tissue debris, and microorganisms
ulcer a break in skin or mucous membrane with loss of surface tissue, disintegration and necrosis of epithelial tissue, and often pus
local infection Occurs when a microbe enters a specific tissue, infects it, and remains confined there.
systemic Occurring throughout the body; said of infections that invade many compartments and organs via the circulation.
bacteremia The presence of viable bacteria in
circulating blood.
viremia The presence of viruses in the
Summarize the three lines of defense. 1) any barrier that blocks invasion at portal of entry. 2) internalized system of protective cells & fluids like inflammation & phagocytosis. 3) acquired on individual basis as each foreign substance is encountered by white bloodcells called lymphocytes.
Outline the steps of inflammation. 1) Injury > Reflex narrowing of blood vessels 2) Increased diameter of blood vessels. 3) Edema > Infiltration of site by neutrophils and accumulation of pus. 4) Macrophages and lymphocytes > Repair,
pyemia septicemia accompanied by multiple abscesses and secondary toxemic symptoms and caused by pus-forming microorganisms (as the bacterium Staphylococcus aureus)
RES (Reticular Endothelial System) mononuclear phagocyte system, it pertains to a network of fibers and phagocytic cells (macrophages) that permeates the tissues of all organs. Examples: Kupffer cells in liver sinusoids, alveolar phagocytes in the lung, microglia in nervous tissue.
septic shock Blood infection resulting pathological state of low blood pressure accompanied by a reduced Endotoxins of all gram-negative bacteria can cause shock, but most clinical cases are due to gram-negative enteric rods.
vasodilation Increased diameter of blood vessels
diapedesis The migration of intact blood cells between endothelial cells of a blood vessel such as a venule.
lysozyme An enzyme found in sweat, tears, and saliva that breaks down bacterial peptidoglycan.
complement in immunology, serum protein components that act in a definite sequence when set in motion either by an antigen- antibody complex or by factors of the alternative (properdin) pathway.
chemotaxis The tendency of organisms to move in response to a chemical gradient (toward an attractant or to avoid adverse stimuli).
inflammation A natural, nonspecific response to tissue injury that protects the host from further damage. It stimulates immune reactivity and blocks the spread of an infectious agent.
interferons peptides used to treat some types of cancer, multiple sclerosis, and viral infections such as hepatitis and genital warts
acquired immunity Immunity obtained either from development of antibodies in response to exposure to an antigen, from vaccination or attack of infectious disease, or from transmission of antibodies.
antigen Any cell, particle, or chemical that induces a specific immune response by B cells or T cells and can stimulate resistance to an infection or a toxin.
antigenic determinants the structural component of an antigen molecule responsible for its specific interaction with antibody molecules elicited by the same or related antigen.
hapten An incomplete or partial antigen. Although it constitutes the determinative group and can bind antigen, hapten cannot stimulate a full immune response without being carried by a larger protein molecule.
self-antigen any molecule or chemical group of an organism which acts as an antigen in inducing antibody formation in another organism but to which the healthy immune system of the parent organism is tolerant
allergen A substance that provokes an allergic response.
T cells A white blood cell that is processed in the thymus gland and is involved in cell-mediated immunity.
T helper-CD4 T cell with CD4 receptor that recognizes antigens on the surface of a virus-infected cell and secretes lymphokines that stimulate B cells and killer T cells; helper T cells are infected and killed by the AIDS virus
T-cytotoxic-CD8 a killer cell that destroys target cells only when specifically activated by helper T cells.
List the 4 major categories of nonspecific immunity Phagocytosis, Inflammation, Fever, Antimicrobial Proteins.
Describe the memory immune response. During potential infection, B & T cells create memory cells; they r clones of specific B & T cells that retain information about threat that the body has been exposed to. This gives the immune system “memory”