0.5 Glossary  (Page 2/18)

B

• β-lactamases bacterially produced enzymes that cleave the β-lactam ring of susceptible β-lactam antimicrobials, rendering them inactive and conferring resistance
• β-lactams group of antimicrobials that inhibit cell wall synthesis; includes the penicillins, cephalosporins, carbapenems, and monobactams; inhibits the transpeptidase cross-linking activity of penicillin-binding proteins
• β-oxidation process of fatty acid degradation that sequentially removes two-carbon acetyl groups, producing NADH and FADH ₂ , on entry into the Krebs cycle
• β-pleated sheet secondary structure consisting of pleats formed by hydrogen bonds between localized segments of amino acid residues on the backbone of the polypeptide chain
• B-cell receptors (BCRs) membrane-bound IgD and IgM antibody that bind specific antigen epitopes with Fab antigen-binding region
• B lymphocyte antibody-producing cells of humoral immunity; B cell
• babesiosis tickborne protozoan infection caused by Babesia spp. and characterized by malaise, fatigue, fever, headache, myalgia, and joint pain
• bacillary dysentery gastrointestinal illness caused by Shigella bacteria, also called shigellosis
• bacillus (bacilli) rod-shaped prokaryotic cell
• bacitracin group of structurally similar peptides that block the movement of peptidoglycan precursors across the cell membrane, inhibiting peptidoglycan synthesis
• bacteremia condition marked by the presence of bacteria in the blood
• bacteria (singular: bacterium) any of various unicellular prokaryotic microorganisms typically (but not always) having cell wells that contain peptidoglycan
• bacterial lawn layer of confluent bacterial growth on an agar plate
• bacterial meningitis bacterial infection that results in an inflammation of the meninges
• bacterial vaginosis a condition caused by an overgrowth of bacteria in the vagina that may or may not cause symptoms
• bactericidal irreversible inhibition of a microbe’s ability to divide
• bactericide chemical or physical treatment that kills bacteria
• bacteriochlorophylls green, purple, or blue pigments of bacteria; they are similar to chlorophyll of plants
• bacteriology the study of bacteria
• bacteriophage virus that infects bacteria
• bacteriostatic having the ability to inhibit bacterial growth, generally by means of chemical or physical treatment; reversible inhibition of a microbe’s ability to divide
• barophile organism that grows under high atmospheric pressure
• basal body component of eukaryotic flagellum or cilium composed of nine microtubule triplets and attaches the flagellum or cilium to the cell
• base sequence identity of the specific nucleotides present in a nucleic acid strand and their order within the strand
• basic dye a chromophore with a positive charge that attaches to negatively charged structures
• basidia (basidium, sing.) small club-shaped structures of basidiomycete fungi where basidiospores are produced
• basidiocarps fruiting bodies of basidiomycete fungi
• basidiospores spores produced sexually via budding in basidiomycete fungi
• basophils leukocytes with granules containing histamine and other chemicals that facilitate allergic responses and inflammation when released
• benzimidazoles class of antihelminthic drugs that bind to helminthic β-tubulin, preventing microtubule formation
• Betaproteobacteria class of Proteobacteria that are all eutrophs
• binary fission predominant form of bacterial reproduction in which one cell divides into two daughter cells of equal size, which separate, each offspring receiving a complete copy of the parental genome
• binocular having two eyepieces
• binomial nomenclature a universal convention for the scientific naming of organisms using Latinized names for genus and species
• biofilm complex ecosystem of bacteria embedded in a matrix
• biogeochemical cycle recycling of inorganic matter between living organisms and their nonliving environment
• bioinformatics the analysis of large amounts of information required for interpretation of these data
• biological transmission movement of a pathogen between hosts facilitated by a biological vector in which the pathogen grows and reproduces
• biological vector an animal (typically an arthropod) that is infected with a pathogen and is capable of transmitting the pathogen from one host to another
• biomarker a protein expressed by a cell or tissue that is indicative of disease
• biomolecule a molecule that is part of living matter
• bioremediation use of microbes to remove xenobiotics or environmental pollutants from a contaminated site
• biosynthesis replication of viral genome and other protein components
• biotechnology the science of using living systems to benefit humankind
• bisbiguanide type of chemical compound with antiseptic properties; disrupts cell membranes at low concentrations and causes congealing of intracellular contents at high concentrations
• blastomycosis fungal disease associated with infections by Blastomyces dermatitidis ; can cause disfiguring scarring of the hands and other extremities
• blepharitis inflammation of the eyelids
• blocking antibodies antigen-specific antibodies (usually of the IgG type) produced via desensitization therapy
• blood-brain barrier tight cell junctions of the endothelia lining the blood vessels that serve the central nervous system, preventing passage of microbes from the bloodstream into the brain and cerebrospinal fluid
• blue-white screening a technique commonly used for identifying transformed bacterial cells containing recombinant plasmids using lacZ -encoding plasmid vectors
• blunt ends ends of DNA molecules lacking single-stranded complementary overhangs that are produced when some restriction enzymes cut DNA
• botulism form of flaccid paraylsis caused by the ingestion of a neurotoxin produced by Clostridium botulinum
• bradykinin activated form of a proinflammatory molecule induced in the presence of invader microbes; opens gaps between cells in blood vessels, allowing fluid and cells to leak into surrounding tissue
• bridge reaction reaction linking glycolysis to the Krebs cycle during which each pyruvate is decarboxylated and oxidized (forming NADH), and the resulting two-carbon acetyl group is attached to a large carrier called coenzyme A, resulting in the formation of acetyl-CoA and CO; also called the transition reaction
• brightfield microscope a compound light microscope with two lenses; it produces a dark image on a bright background
• broad-spectrum antimicrobial drug that targets many different types of microbes
• bronchi major air passages leading to the lungs after bifurcating at the windpipe
• bronchioles smaller air passages within the lung that are formed as the bronchi become further subdivided
• bronchitis inflammation of the bronchi
• brucellosis zoonotic disease caused by bacteria of the genus Brucella that results in undulant fever
• bubo swollen, inflamed lymph node that forms as a result of a microbial infection
• bubonic plague most common form of plague in humans, marked by the presence of swollen lymph nodes (buboes)
• budding unequal reproductive division in which a smaller cell detaches from the parent cell
• budding yeasts yeasts that divide by budding off of daughter cells
• Burkitt lymphoma disease characterized by rapidly growing solid tumor; caused by Epstein-Barr virus (HHV-4)
• burst release of new virions by a lysed host cell infected by a virus
• burst size the number of virions released from a host cell when it is lysed because of a viral infection