Glossary
Browse the glossary using this index
Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | ALL
A |
|---|
acidificationThe process of becoming more acidic. | |
acquired resistanceResistance to an antibiotic to which a bacterium is innately susceptible. It occurs when a bacterium acquires the ability to resist the actions of a particular antibiotic through either genetic mutation or horizontal gene transfer. | |
amino acidThe individual unit from which proteins are constructed. | |
aminoglycoside antibioticsA class of antibiotics containing an amino sugar that targets protein synthesis, e.g. streptomycin. | |
amino sugarA sugar molecule in which a hydroxyl (-OH) group is replaced by an amine (-NH2) group. | |
antagonistsSubstances that interfere with a physiological process. | |
antibiotic pipelineNovel antibiotics that are newly discovered or in the development phase before being approved for clinical use. | |
antibiotic prophylaxisThe use of antibiotics as a precaution to prevent, rather than treat, an infection. | |
antibiotic resistanceThe ability of bacteria to resist the action of antibiotics so that they survive exposure to antibiotics that would normally kill them or stop their growth. | |
antibodiesProteins found in blood that are produced as an immune defence against foreign agents. | |
antimetabolitesChemicals which are structurally similar to
natural metabolites but just different enough to interfere with normal cell
function. | |
B |
|---|
bacteraemiaThe presence of viable bacteria in the circulating blood. | |
bacteriaSingle cell prokaryotes. The oldest, smallest and most numerous organisms living on Earth. (Singular: bacterium) | |
bacterial endocarditisA bacterial infection of the inner lining of the heart (the endocardium). | |
bactericidalAntibiotic that kills bacteria. | |
bacteriophage | |
bacteriostaticAntibiotics that stop or slow bacterial growth. | |
batch fermentationAn industrial process for the large-scale production of microbes and/or metabolites in liquid culture. After the microbe is introduced to the culture no additional growth medium is added. | |
Bdellovibrio bacteriovorus | |
binary fissionA form of asexual reproduction used by bacteria and other prokaryotic cells in which one cell divides to form two. | |
biofilmAn aggregation of bacterial cells embedded in a carbohydrate matrix and attached to a surface or tissue. | |
biomarkersBiological molecules that can be used as a measurable indicator of a biological state or condition. | |
bioprospectingThe systematic search for organisms and natural compounds from which antibiotics and other drugs might be derived. | |
broad-spectrumAntibiotics that affect a wide range of bacteria. | |
C |
|---|
cefotaximeA third-generation broad-spectrum cephalosporin antibiotic. | |
ceftazidimeA third-generation broad-spectrum cephalosporin antibiotic. | |
central dogmaThe one-way flow of information from DNA to RNA to protein. First proposed by Francis Crick in 1958. | |
chemical librariesCollections of chemical compounds that can be screened for compounds with potential antibiotic activity. | |
chemically labileThe tendency of a substance to be easily broken down during a chemical reaction. | |
chemical messengersChemical compounds that transmit messages between cells. | |
chromosomesDNA molecules containing some, or all, of the genetic information of an organism. | |
commensalsBacteria that live associated with the host organism without having a detrimental effect on the host. For example, Streptococcus pyogenes is a commensal bacterium often found in the nose of healthy individuals. | |
conjugationA horizontal gene transfer mechanism in which plasmids are transferred between two contacting bacteria through a hollow tube, or pilus. | |
contagionThe spread of a disease from one person to another by close contact. | |
correlationA relationship between two sets of data. For example, as antibiotic use increases, antibiotic resistance also increases. | |
CTX-M-type ESBLThe most common class of extended spectrum β-lactamases worldwide that act against cephalosporins. | |
D |
|---|
deoxyribonucleic acid (DNA)A macromolecule comprised of two chains of complementary nucleic acids. Heritable genetic information is encoded by the sequence of nucleotides in DNA. | |
diverticulitisAn infection of pockets in the lining of the large intestine. | |
E |
|---|
efficacyThe ability of a drug to produce a therapeutic effect. | |
efflux pumpTransport proteins in the bacterial membrane actively transport antibiotics out of the bacterial cell. | |
empirical diagnosisA diagnosis based on clinical experience, using the visible signs and symptoms experienced by a patient. | |
empiric treatmentAntibiotic therapy administered without a definitive diagnosis and often based on clinical observation and experience. | |
enterobacteriaA family of Gram-negative bacteria, including Salmonella spp. and Escherichia coli. | |
enzymesProteins that speed up (catalyse) chemical reactions in living organisms. | |
eukaryotesOne of the two main categories of living things (the other is prokaryotes). Eukaryotic organisms, including humans and animals, have cells containing nuclei and other membranous organelles. | |
evolutionThe process by which all living organisms develop from a common ancestor. A change over time in the inherited characteristics or traits in a population. This change is largely brought about by natural selection. | |
extended spectrum cephalosporins (ESCs)Cephalosporins with greater activity against Gram-negative bacteria than first-generation cephalosporins. | |
extended spectrum β-lactamase (ESBL)An enzyme that destroys a broad spectrum of β-lactam antibiotics, including penicillin and cephalosporins. | |
F |
|---|
faecal–oral transmissionThe route of infection in which pathogens are transmitted directly from hand to mouth or via faecally contaminated food, water or utensils. | |
fomitesObjects in the environment, such as door handles, cups and pens, that are routinely touched and can transmit infections. | |
G |
|---|
geneA sequence of DNA that encodes the amino acid sequence of a particular protein. | |
generationsA classification system for cephalosporins based on their spectrum of activity. | |
genetic mutationsChanges in the sequence of DNA due to either errors made while copying the DNA or environmental factors. Genetic mutations in genes can result in changes to the amino acid sequence encoded by the gene. | |
genomeThe complete set of DNA of an organism. | |
germ theoryThe theory that many diseases are caused by microorganisms. | |
Gram-negativeBacteria that do not retain crystal violet dye in the Gram-staining test. | |
Gram-positiveBacteria with a thick peptidoglycan layer in their cell wall that is stained blue–purple by the Gram stain dye. | |
Gram stainingA cell-staining method used to visualise the composition of the bacterial cell wall and to identify and classify bacteria. | |
Greiss reactionAn analytical chemistry test that detects the presence of nitrites in a solution. | |
H |
|---|
high-income countries (HICs)Countries with a gross national income per capita classified as high income by the World Bank. | |
horizontal gene transferThe process of swapping genetic information between two unrelated cells. It is the primary mechanism of spreading antibiotic resistance because it allows bacteria to spread antibiotic resistance genes rapidly between different species. | |
hydroscopicA substance that can absorb water from its surrounding environment. | |
hydroscopicityThe tendency of a substance to absorb water from its surroundings. | |
I |
|---|
infectious doseThe amount of pathogen needed to cause an infection in the host. | |
interventionAn activity that promotes behaviours that improve health. | |
intrinsically susceptibleA bacterial species that naturally lacks resistance mechanisms and is sensitive to the action of an antibiotic. | |
intrinsic resistanceThe innate ability of a bacterial species to resist the action of antibiotic as a consequence of the bacteria’s structural or functional characteristics. | |
isolateA bacterial strain separated from a mixed population of microbes such as those found in the soil or inside the gut. | |
K |
|---|
Kluyvera spp.Non-pathogenic soil bacteria that are the source of CTX-M-type ESBLs. | |
L |
|---|
listeriosisA rare infection caused by the bacterium Listeria. | |
low-income countries (LICs)Countries with a gross national income per capita classified as low income by the World Bank. | |
low-middle-income countries (LMICs)Countries with a gross national income per capita classified as low or middle income by the World Bank. | |
lysinEnzyme produced by a bacteriophage that is required to lyse bacteria. | |
lysisThe process by which cells burst open and die. For example, as a consequence of too much water entering the cell by osmosis. | |
M |
|---|
metabolismThe chemical reactions in an organism that allow it to obtain the energy and nutrients it needs to grow and survive. | |
metabolitesThe intermediates and products of metabolism. | |
methicillin-resistant Staphylococcus aureus (MRSA)Bacteria that cause infections that are resistant to many commonly used antibiotics. | |
microorganismsPathogenic and non-pathogenic microscopic organisms, including bacteria, fungi, protists and viruses. | |
molecular diagnosticsDiagnostic tests that use molecular biology techniques such as PCR to analyse DNA from the patient or pathogen in order to diagnose disease. | |
morbidityA measure of the illness or disability experienced by a population. | |
mortalityA measure of the deaths in a population. | |
multidrug resistanceThe resistance of a bacterial species to multiple antibiotics. | |
N |
|---|
nanometre (nm)Unit of length equal to one billionth of a metre. | |
nanoparticlesParticles between 1 and 100nm in size. | |
narrow-spectrumAntibiotics that only affect a small range of bacterial types. | |
natural selectionThe process that ensures that advantageous traits become more frequent in the population. | |
non-target-based screeningSystematic screening of microbes for extracts with non-specified antibacterial activity. | |
nosocomial infectionsInfections that are acquired in hospital. | |
O |
|---|
OECD countriesCountries that are members of the Organisation for Economic Cooperation and Development. | |
opportunistic pathogensMicroorganisms that are normally commensal and do not harm their host but can become pathogenic and cause infection when the host's immune defences are compromised. | |
organellesMembrane-bound components of eukaryotic cells that are specialised to carry out particular functions. | |
osmosisThe process by which water moves through a partially permeable membrane from a less concentrated solution of, for example, salt (where there is a relatively high concentration of water and a low concentration of salt) to a more concentrated one (where there is a relatively low concentration of water and a high concentration of salt). | |
P |
|---|
pathogenicCapable of causing disease. | |
penicillinaseThe first identified β-lactamase. It hydrolyses and destroys penicillin but not other β-lactam antibiotics such as cephalosporins. | |
penicillin-binding protein 2a (abbreviated to PBP2a)A penicillin-binding protein with low affinity for penicillin and other β-lactams. | |
penicillin-binding proteins (PBPs)Bacterial enzymes that are essential for bacterial cell wall synthesis. They are the target of β-lactam antibiotics. | |
peptidoglycanA major component of bacterial cell walls. A large polymer, consisting of sugars and amino acids, that forms a mesh-like layer outside the bacterial cell membrane. | |
phage therapyTreatment for bacterial infections that exploits the ability of bacteriophages to lyse and kill the bacteria they infect. | |
pharmacological propertiesThe characteristics of a drug that relate to how it is used and its effects in the body. | |
pH indicatorA chemical compound that changes colour in solution, depending on the pH (acidity) of the solution they are mixed with. | |
phytochemicalChemicals produced by plants. Many phytochemicals have antibacterial properties. | |
pilusA thin hollow tube extension of the bacterial cell wall that connects bacteria and is involved in horizontal gene transfer via conjugation. | |
plasmidA circular, non-chromosomal piece of DNA often carrying genes associated with a particular function, e.g. antibiotic resistance. | |
point-of-care (POC)‘point-of-care is the specific location at which a patient is presenting with illness – this could be at home, or in a range of primary and secondary healthcare settings. Point-of-care diagnosis therefore takes place close to the patient, rather than at a physically removed central laboratory.’
Bailey, S. (2017) ‘What do we mean by point of care?’, Longitude Prize, 4 May 2017 [Blog]. Available at https://longitudeprize.org/blog-post/longitude-prize-what-do-we-mean-point-care (Accessed 28 February 2018). | |
polymerase chain reaction (PCR)A laboratory technique that permits the analysis of short DNA sequences in a sample. PCR is used to amplify short sections of DNA for analysis. | |
porinA transmembrane protein complex that allows the movement of small molecules across the bacterial outer membrane. | |
primary barrierSanitation and hygiene barrier that prevents initial contact with faeces. For example, providing people with access to flushing toilets. | |
primary metabolitesA type of metabolite directly involved in growth and development. | |
procalcitonin (PCT)A precursor of the hormone calcitonin. Levels of PCT rise in patients with bacterial, but not viral, infections. Consequently, it can be used as a biomarker for bacterial infections. | |
prokaryotesOne of the two main categories of living things (the other is eukaryotes). Prokaryotic cells lack a nucleus, mitochondria and other membrane-bound organelles.  | |
prophylacticallyGiving a medicine or treatment to a healthy individual in order to prevent disease occurring. | |
proteinA large molecule consisting of long chains of amino acids that performs many essential functions within cells. | |
public health‘the art and science of preventing disease, prolonging life and promoting health through the organized efforts of society’ (Winslow, C.-E. A. (1920) ‘The untilled fields of public health’, Science, vol. 51, no. 1306, pp. 23–33). | |
Q |
|---|
quorum sensingThe process by which bacteria communicate with each other. It allows bacteria to share information about cell density and change their behaviour accordingly. For example, at high cell density, Vibrio fischeri bacteria alter their behaviour to emit fluorescent light. At low cell density, the bacteria are not fluorescent. | |
R |
|---|
rapid diagnosticsMedical diagnostic test that is quick and provides a rapid read-out that can be used to diagnose the patient. | |
reactive oxygen species (ROS)Chemically reactive chemical compounds containing oxygen, for example hydrogen peroxide (H2O2). They can damage DNA and proteins. | |
replicationThe synthesis of an exact copy of a DNA molecule. | |
resistance breakersDrugs that do not kill bacteria themselves but, when co-administered with a failing antibiotic, can overcome resistance. | |
ribosome | |
RNA (ribonucleic acid)A type of nucleic acid. Serves as an intermediate in the conversion of genetic information, encoded in DNA, into a protein. | |
S |
|---|
secondary barrierA sanitation and hygiene barrier that prevents infectious pathogens being ingested by a future victim. For example, using a clean water source when preparing food. | |
secondary metabolitesA type of metabolite that is not essential for growth and development. | |
selection | |
selective pressureThe factors that contribute to selection. For example, predation, nutrients or the presence of antibiotics. | |
selective toxicityThe targeting of drugs to affect only the disease-causing, pathogenic organism and minimise damage to the host cells and commensals. | |
self-medicateTo take drugs bought over-the-counter without medical supervision. | |
semi-permeable membranesMembranes that allow only some molecules to pass through. | |
streptomycinAn aminoglycoside antibiotic routinely used to treat several bacterial infections, including tuberculosis. | |
structural analogueA compound having a structure similar to that of another compound but a different function. | |
substrateThe chemical on which an enzyme acts. It binds to the enzyme and is converted into a product or products through the action of the enzyme. | |
sub-therapeuticA dose of drug that is below the level required to treat disease. | |
subunitA single amino acid chain that forms a protein in complex with other subunits. | |
synergisticallyWhen two substances act together to create an effect that is greater than the effect seen when using either substance alone. | |
T |
|---|
traitA genetically determined characteristic of an organism. | |
transcription profilingA technique that identifies which genes are being expressed in cells. | |
transductionA horizontal gene transfer mechanism in which plasmids are transferred from one bacterium to another, mediated by a virus. | |
transformationA horizontal gene transfer mechanism in which bacteria take up plasmids from the environment across the cell wall. | |
transmissionThe passing of disease-causing pathogens from one individual to another. | |
turbidityA measure of how well light passes through a liquid. Light is scattered by particles in liquid, making them appear cloudy, or turbid. Turbidity can be used to measure bacterial cell density. Samples with a high cell density will appear more turbid than those with a low cell density. | |
V |
|---|
vertical gene transferThe transfer of genetic information from a parent to its offspring. | |
virusAn infectious agent that is approximately 10 times smaller than a bacterium. Viral infections cannot be treated with antibiotics. | |
Î’ |
|---|
β-lactamaseAn enzyme that destroys β-lactam antibiotics by hydrolysing the β-lactam ring. | |
β-lactamase inhibitorAn enzyme inhibitor that prevents the degradation of β-lactam antibiotics by β-lactamases. Used as resistance breakers. | |