Glossary

A Glossary compiled by students from MCB 233:

abscess A localized collection of pus in part of the body; formed by tissue disintegration and surrounded by an inflamed area
acid-resistant Refers to organisms that are resistant to acid washout of stain due to a tough outer wax covering; characteristic of tubercle bacillus
ACIP Advisory Committee for Immunization Practices
aerobic Containing oxygen; referring to an organism, cellular process, or environment that requires oxygen
aerosol Droplet suspended in the air that may contain microorganisms; major route of inhalation transmission
agar A gelatinous material derived from certain marine algae; base for bacterial culture media
agglutination The clumping together of red blood cells or bacteria, usually in response to a particular antibody
amantadine An antiviral drug, C10H17N·HCl, also used in the treatment of Parkinson's disease; particularly used for influenza virus
ameba Any of various one-celled aquatic or parasitic protozoans of the genus Amoeba or related genera, having no definite form and consisting of a mass of protoplasm containing one or more nuclei surrounded by a flexible outer membrane. It moves by means of pseudopods
amphotericin B An antibiotic derived from strains of the actinomycete Streptomyces nodosus and used specifically in treating systemic fungal infections
anaerobic Not containing oxygen; referring to an organism, cellular process, or environment that does not require oxygen
anemia A pathological deficiency in the oxygen-carrying component of the blood, measured in unit volume concentrations of hemoglobin, red blood cell volume, or red blood cell number
antibody An antigen binding immunoglobin; effector in immune response produced by B cells
antigen A substance that when introduced into the body stimulates the production of an antibody; includes anything the body sees as foreign
antigenic drift Refers to minor changes in viral proteins due to gene mutations (point); usually refers to influenza virus
antigenic shift Refers to major changes in viral proteins due to gene reassortment; usually refers to influenza virus
asexual Relating to, produced by, or involving reproduction that occurs without the union of male and female gametes, as in binary fission or budding
asymptomatic infection A type of infection without symptoms
attenuated Refers to a bacteria or virus that has been made to be less virulent; often used in vaccines
B-cells (B- Lymphocytes) Lymphocytes that respond to antigen by proliferation and differentiation into memory cells and plasma cells; plasma cells secrete antibody; differentiate in the bone marrow
binary fission One mode of asexual reproduction that involves the splitting of a parent cell into two approximately equal parts
biofilm A complex, multi-cellular structure formed by certain bacteria when they adhere to surfaces in aqueous environments; Characterized by excretion of slimy, glue-like substances that can anchor them to many types of materials
bronchitis Chronic or acute inflammation of the mucous membrane of the bronchial tubes
cAMP cyclic AMP; a second messenger of eukaryotic cells
capsid The protein covering of some viruses; composed of capsomere subunits; possible stimulus for immune response
capsule Slimy outer coating of bacteria; a virulence factor that confers resistance to phagocytosis
carrier A person/animal that shows no symptoms of a disease but harbors the infectious agent of that disease and may transmit it to others
CDC Centers for Disease Control and Prevention
chloroquine A drug, C18H26ClN3, used mainly in the treatment and prevention of malaria
complement Refers to a protein belonging to the complement system- a branch of innate immunity responsible for inflammatory response, phagocytosis, and cell lysis in response to foreign cells
conformational change A predictable movement within a protein that is associated with biological activity
cyst Dormant form of a protozoa; stable transmitted form that is resistant to dessication
cytoplasm Entire contents of the cell that excludes the nucleus and is bound by theplasma membrane
cytotoxic Refers to substances that are toxic to cells
dehydroemetine A synthetic derivative of emetine; used in the treatment of intestinal amoebiasis
desiccation To dehydrate or remove water content
diloxanide furoate 2,2-Dichloro-4'-hydroxy-N-methylacetanilide furoate; an amoebicide used in the treatment of dysentery
dimorphic phenomenon of fungi to exist as both different growth forms under different environmental conditions, either as molds or yeast- filamentous and unicellular respectively
disseminate Spread of an organism to a distant site
doxycycline A broad-spectrum antibiotic, C22H24N2O8, derived from tetracycline
edema An excessive accumulation of serous fluid in tissue spaces or a body cavity
electrolyte Various ions, such as sodium, potassium, or chloride, required by cells to regulate the electric charge and flow of water molecules across the cell membrane
ELISA (Enzyme-linked immunosorbent assay) A highly sensitive immunoassay that uses an enzyme linked to an antibody or antigen as a marker for the detection of a specific protein, usually an antigen or antibody; often used as a diagnostic test to determine exposure to a particular infectious agent by identifying antibodies present in a blood sample
endemic Refers to a type of disease or pathogen that is consistently found in a population; examples are dental caries, gonorrhea, and athlete’s foot
endoplasmic reticulum An extensive membrane network’ continuous with the nucleus, found in eukaryotic cells; two versions- rough and smooth
Enterovirus small viruses that are made of ribonucleic acid (RNA) and protein. This group includes the polioviruses, coxsackieviruses, and echoviruses
epidemic A local outbreak of disease in a population that is determined by an increase above the baseline level for the population
epithelial cells Compose the epithelial layer- cells separated by very little intercellular substance and form the covering of most internal and external surfaces of the body and its organs
erythrocytes Red blood cells
erythromycin An antibiotic obtained from a strain of the actinomycete Streptomyces erythreus, effective against many gram-positive bacteria and some gram-negative bacteria
exotoxins Toxins that are secreted by a microorganism and released into the medium in which it grows
fastidious Refers to organisms that have complex nutritional requirements; characteristic of parasitic species
fimbriae Protrusions from the cell surface usually referring to pili; responsible for bacteria attachment to surfaces
fungus Eukaryotes belonging to the kingdom Eumycota; free living in environmental sources; usually dimorphic; pathogenic strains can cause superficial, cutaneous, subcutaneous, or systemic infection
G protein A GTP binding protein that acts as a switch to turn activities on or off
gametocyte A cell from which gametes develop by meiotic division, usually refers to a spermatocyte or an oocyte
gastroenteritis Inflammation of the mucous membrane of the stomach and intestines
Gram negative Group of bacteria that do not retain crystal violet staining and instead stain red or pink; reflective of the lack of the peptidoglycan layer; contain Lipopolysaccharide (endotoxin)
hemolysin A substance, such as an antibody or a bacterial toxin, that causes the destruction of red blood cells; results in the release of hemoglobin
hemorrhage Excessive loss of blood from the blood vessels; profuse bleeding
hepatocyte A parenchymal cell of the liver
humoral The branch of immunity that includes antibodies
icosahedral One type of arrangement of the capsomer subunits of the viral capsid; icosahedral symmetry refers to an arrangement of 20 triangular faces and 12 vertices
immunity Inherited, acquired, or induced resistance to infection by a specific pathogen
immunoglobin Refers to a superfamily of proteins that have similar domains andcompose the polypeptide chains of antibodies
in vitro In an artificial environment outside the living organism
in vivo Within a living organism
incidence Refers to diease transmission, the number of cases of the disease in a specific subset of the population
incubation period The period between infection and the appearance of symptoms of the disease
inflammation A localized protective reaction of tissue to irritation, injury, or infection, characterized by pain, redness, swelling, and sometimes loss of function
interleukin-1 A cytokine involved in many inflammatory effects including fever induction, increased adhesion molecules, increased vascular permeability and induction of respiratory burst
iodoquinol One of the halogenated 8-quinolinols widely used as an intestinal antiseptic, particularly as an antiamebic agent; also used topically in other infections
itraconazole A broad-spectrum antifungal agent administered orally to treat a variety of fungal infections
lipid A Lipid anchor of Lipopolysaccharide layer of gram negative bacteria; composed of disaccharides with short chain fatty acid and phosphate group attachments
LPS Bacterial lipopolysaccharide, outer bilayer of gram negative bacteria; endotoxin
lysis The dissolution or destruction of cells; usually by the action of a specific lysin that disrupts the cell membrane
lytic cycle Type of viral replication cycle that results in the release of new phages by lysis of the host cell
malaise Unspecified feeling of bodily discomfort; as at the beginning of an illness
meningitis Inflammation of the meninges of the brain and the spinal cord; of bacterial or viral origin, characterized by fever, vomiting, intense headache, and stiff neck
morbidity rate Incidence of disease in a population, includes fatal and nofatal cases
mortality rate The ratio of deaths in an area to the population of that area; expressed per 1000 per year
mucus Slimy covering of some membranes that provides a protective mechanical and chemical barrier
necrosis Refers to cell death as a result of injury or disease, especially in a localized area of the body
neutrophil A granular white blood cell capable of phagocytosis
non-motile Not capable of movement
nonenveloped Category of viruses without an envelope; the envelope is usually comprised of virus specific proteins plus host derived components
nosocomial Refers to hospital acquired infection
nucleus The organelle that contains the eukaryotic cell’s genetic material
opportunistic pathogen A pathogen that is marginally pathogenic and requires an compromised host to cause serious infection
parasite An organism that grows, feeds, and is sheltered on or in a different organism and does not contribute anything to host survival
paromomycin An antibiotic in pill form used for the treatment of intestinal infections, cryptosporidiosis in particular; Possible side effects include stomach upset and diarrhea
Peyer’s patches Lymphoid nodules found in the small intestines
pneumonia An acute or chronic disease characterized by inflammation of the lungs; usually caused by viruses, bacteria, or other microorganisms
point mutation A mutation that changes only one small area of one nucleotide of a gene
protease Refers to an enzyme that catalyzes the hydrolytic breakdown of proteins into peptides or amino acids; including the endopeptidases and exopeptidases
quorum sensing Regulatory pathways in prokaryotes that respond to population density
receptor-mediated endocytosis Refers to the uptake of specific extracellular macromolecules following their binding to specific receptors on the external surface of the plasma membrane
reservoirs Sources of pathogens in the environment that do not participate directly in transmission to humans, examples
rimantadine An RNA synthesis inhibitor that is used as an antiviral agent in the prophylaxis and treatment of influenza
RNA Ribonucleic Acid
saprophytic Refers to an organism that grows on and derives its nourishment from dead or decaying organic matter; especially fungus or bacteria
seasonal distribution Refers to the pattern of disease of a pathogen that varies with the season; example rotavirus has a defined seasonal distribution
septate hyphae Hyphae are filaments that molds grow as; septate refers to hyphae that are divided by partitions
strain A group of organisms of the same species, having distinctive characteristics but not usually considered a separate breed or variety
systemic infection An infection not localized in the body, disseminated widely throughout the body
T-cells (T- Lymphocytes) Lymphocytes that respond to antigen by proliferation and differentiation into Cytotoxic T-cells and Helper T-cells; differentiate in the thymus
tissue tropic A pathogen’s predilection for specific tissues either due to chemotaxis or specific receptors and environments
trophozoite Active form of a protozoa; capable of growth and replication by binary fission
tuberculate Refers to tubercles
tumor necrosis factor (TNF-alpha) A cytokine secreted by activated macrophages and T-cells whose action includes inflammatory effects, apoptosis, cachexia, and induction of fever
vaccine A preparation of a weakened or killed pathogen, such as a bacterium or virus, or of a portion of the pathogen's structure that upon administration stimulates antibody production or cellular immunity against the pathogen but is incapable of causing severe infection
vector An organism that carries disease-causing microorganisms from one host to another; for example a mosquito or tick
virulence factors Microbial characteristics that increase infectivity or severity of disease; examples include adhesins, toxins, and LPS
zygote The cell formed by the union of two gametes, for example a fertilized ovum before cleavage