A Glossary compiled 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: toxins, bacteria, foreign blood cells, and the cells of transplanted organs

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: metals, plastics, soil particles, and tissue; Characteristic of P. aeruginosa growth

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

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

G protein: A GTP binding protein that acts as a switch to turn activities on or off

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
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

in vitro: In an artificial environment outside the living organism

in vivo: Within a living organism

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

nonenveloped: Category of viruses without an envelope; the envelope is usually comprised of virus specific proteins plus host derived components

non-motile: Not capable of movement

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: humans, animals, environment

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
trophozoite: Active form of a protozoa; capable of growth and replication by binary fission

tissue tropic: A pathogen’s predilection for specific tissues either due to chemotaxis or specific receptors and environments

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

tuberculate: Refers to tubercles : Nodules or swellings, especially a mass of lymphocytes and epithelioid cells; characteristic lesion of tuberculosis

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


© 2003, J.Graf, for comments please contact Joerg.Graf@uconn.edu