Glossary of Scientific Terms

Acute Coronary Syndrome

reduction in the diameter of the coronary arteries, which decreases blood flow and leads to insufficient oxygenation of the myocardial muscle.

Acute Kidney Injury (AKI)

a sudden failure of kidney function developing within 7 days. It is a broad clinical syndrome encompassing various etiologies, including specific kidney diseases, which may occur in the community as well as in hospitals and intensive care units.

Amplification

technique most often based on enzymes, allowing to multiply nucleic acids to increase the sensitivity of the detection methods.

Antibiotic

a substance of natural or synthetic origin, with the ability to stop the multiplication of bacteria.

Antibiotic susceptibility test

analysis to determine the sensitivity of a bacterium to antibiotics and to classify it as sensitive, resistant or intermediate.

Antibodies

molecules produced by the immune system to detect and neutralize pathogens, particularly viruses.

Antigen

a substance foreign to an organism that causes it to form an antibody (immune reaction).

Bacteria

unicellular microorganisms without chlorophyll and visible only under the microscope. Bacteria are elements that do not belong to the plant or animal kingdom.

Bacteriophages

highly specific viruses that only infect bacteria. They are used for the selective capture of bacteria and for isolating them from a sample.

Biochemistry

science that studies the correlation between the structure of natural molecules and the consequences on their activity.

Biomarker / marker

any indicator (nucleic acid, enzyme, metabolite or other types of molecules: histamine, hormone, protein, etc.) present in the body or excreted by it, as a biological response to a physiological or pathological state. A biomarker is likely to identify the presence, effect and/or measurement of particular phenomena, such as    - the rapid or early detection of a disease, before the first symptoms, the progression of a disease and the impact of a drug or a treatment.

Blood culture

a laboratory test used to detect a bloodstream infection. It consists of collecting a venous blood sample, which is then cultured to determine the presence or absence of pathogenic micro‑organisms.

Campylobacter

a genus of Gram-negative bacteria that can cause food poisoning.

Candida albicans

the most important and best-known yeast species of the Candida genus. It causes infections (candidiasis), mainly of the digestive and vaginal mucosa.

Carbapenemases

b-lactamase type enzymes which hydrolyze carbapenems, a class of antibiotics with extended-spectrum activity, mainly used for the treatment of multi-drug resistant bacterial infections.

Chromogen

molecule that gives off a color under certain conditions. When incorporated into a culture medium, it reveals the presence of an enzyme specific to a given bacteria, thereby indicating the bacteria that is cultured.

Commensal bacteria

the skin and mucous membranes are permanently colonized by commensal bacteria that do not cause disease, unless the subject becomes fragile.

Consumable

a single-use accessory, generally employed in an analysis instrument.

Contaminant

a substance present where it should not be.

Corynebacterium

a genus of bacteria including many species of Gram-positive bacilli which account for a large proportion of the flora of the skin and of the mucosa.

Culture medium

 a simple or complex nutrient composition in liquid or solid form, used to maintain or increase the development of a microbial species under appropriate biological conditions.

Cytology (or cellular biology)

 an area of biology concerning the study of cells and their organelles, the vital processes taking place therein as well as the mechanisms allowing for their survival (reproduction, metabolism).

Cytomegalovirus

 a virus responsible for infections, usually undetected. It becomes pathogenic especially in patients with weak immune defenses. Member of the herpes virus family, which includes inter alia herpes simplex virus (HSV) or herpes virus hominis (HVH), cytomegalovirus (CMV), varicellazoster virus (VZV) and Epstein-Barr virus (EBV).

Cytometry

the counting of cells.

DNA

the acronym of "Deoxyribonucleic Acid". These nucleotides consist of a sugar (deoxyribose), a phosphate group and one of the following nitrogen-containing bases: adenine (A), cytosine (C), guanine (G) or thymine (T), and serve as a medium for genetic information.

DNA sequencing

 method used to determine the order of the nucleotide bases for a given DNA fragment.

Endotoxin

component of the outer membrane of certain Gram-negative bacteria that can cause high fevers. 

Enterobacteria

a family of bacilli (bacteria) revealed by Gram-negative staining which are aerobic or anaerobic (they can live and reproduce with or without oxygen).

Enterococcus

oval-shaped bacterium of the group D of the Streptococcus family, usually resident in the intestine of healthy humans.

Enumeration

counting how many microbes (bacteria or fungi) are present in a sample.

Enzyme

a protein macromolecule which speeds up a biochemical reaction.

Extended-spectrum beta-lactamase

beta-lactamases are a family of enzymes responsible for the resistance of bacteria to certain antibiotics such as penicillin.

Extraction

term applied to the steps which extract nucleic acids from the cells that contain them and process them so they can be used in molecular biology techniques such as amplification.

Flow cytometry

technique of passing a stream of cells, particles or molecules at high speed through a laser beam. The light re-emitted (by diffusion or fluorescence) enables the population to be classified and sorted according to several criteria.

Functionalized polymer

 an organic or inorganic macromolecule formed by a chain of repeating units to which chemical groups are grafted in order to give the macromolecule a particular function.

Fungal

that which relates to fungi.

Genotyping

 determination of all the genes contained in the cells of an organism.

Gram staining

a staining technique that reveals the properties of the bacterial cell wall, allowing bacteria to be distinguished and classified. The main distinction is between Gram‑positive and Gram‑negative bacteria.

HLA

 the acronym of “Human Leukocyte Antigens” : histocompatibility antigens whose role is essential in the tolerance of organ transplants and which are specific to a given individual.

Healthcare-Associated Infections

 a disease contracted in a hospital or other healthcare establishment by a patient who did not have this disease on admission.

Healthcare-associated infection

 an infection that patients acquire during the course of receiving treatment for other conditions within a hospital or healthcare setting.

Histology

 the study of tissue in order to research tissue composition, structure and renewal and cellular exchanges within themselves.

IVD

abbreviation for in vitro diagnostics.

Immunoassay

  diagnostic test based on an antigen/antibody reaction, enabling the detection of infectious agents (bacteria, viruses, parasites) and pathogen markers.

In vitro diagnostics

 analysis of biological samples (urine, blood, etc.) performed outside the human body.

In vivo diagnostics

 tests or research performed on a living organism.

Listeria

 a genus of bacteria that can cause listeriosis, an infectious disease which is potentially serious in new-born babies, pregnant women or individuals with low resistance.

MRSA

 methicillin-resistant Staphylococcus aureus bacterium.

Marker

 a reagent used to detect the substance to which it is bound. A biological marker (biomarker) is a substance that is assayed to help diagnose a pathology.

Mass spectrometry

a technique used to identify a molecule and determine its chemical structure by analyzing the mass and the charge of its ions. 

Methicillin

 a semi-synthetic penicillin used primarily against non-resistant Staphylococcus aureus.

Microbiology

 study of microorganisms. In the field of in vitro diagnostics : culturing , food and pharmaceutical samples in growth medium allows any bacteria that may be present to multiply.The bacteria are subsequently identified and their susceptibility to antibiotics tested in certain cases.

Microorganism

 a living organism of microscopic size.

Molecular biology

technique that allows the detection of a bacterium, a virus, a yeast, a parasite or a biomarker by the presence of genetic sequences of DNA or RNA in a sample.

Multi-resistant bacteria

a bacterium is said to be multi-resistant to antibiotics when, due to the accumulation of natural and acquired resistances, it is only sensitive to a small number of antibiotics that are usually active in therapy.

Multiplex

 the ability to transmit multiple data on a single physical medium.

Mycobacteria

 rod-shaped bacillus-type bacteria. Some species of mycobacterium are pathogenic : M. leprae responsible for leprosy; M. tuberculosis, responsible for tuberculosis.

Nucleic acid

 a naturally-occurring molecule found in each cell. It has the ability to hold and transmit coded hereditary instructions allowing for an organism's development. There are two types of nucleic acids: DNA and RNA.

Oncology

 the medical specialty of the study, diagnosis and treatment of cancers.

PCR (Polymerase Chain Reaction)

 molecular biology technology for in vitro amplification of genetic sequences, used to copy known DNA or RNA sequences in large quantities (by an order of magnitude of a billion) from an initially small quantity. This technology is particularly useful for detecting the presence of viruses.

PCT (Procalcitonin)

 an early and specific host marker of a bacterial infection, PCT is useful to adapt antimicrobial prescriptions.

POC / POCT

 services offered “at the bedside”, including in particular the analysis of the diagnosis.

Parasite

 an organism that feeds off, lives or reproduces itself by establishing a lasting interaction with another organism (the host).

Pathogen

 a microbe that causes or has the potential to cause an infectious disease.

Phage recombinant protein

 bacteriophage tail protein that has been obtained by a biological process.

Protein

 a basic constituent of all living cells. A biological macromolecule is composed of one or more amino acid chains linked by peptide bonds.

Pulmonary embolism

obstruction of one of the branches of the pulmonary artery or of the pulmonary artery itself by a blood clot.

Quality indicator

a term used in the agri‑food industry to define micro‑organisms responsible for visual or taste alterations (e.g., mold or bacterial contamination). Counting quality indicators helps assess the hygiene level of a product.

RNA

the acronym of "ribonucleic acid". A polymer similar to DNA which, like DNA, has a role as a vector of genetic information. The sugar in RNA is a ribose.

Rheumatoid arthritis

the most frequent chronic inflammatory rheumatism. Its cause is not fully known, but it is one of the autoimmune diseases (the body produces antibodies against its own tissues).

Sepsis

 a serious systemic infection characterized by the presence of bacteria, fungi, viruses and parasites in the blood and combined with an inflammatory immune-reaction (host response) that can result in the rapid deterioration of the patient’s general condition leading to possible organ failure. 

Septic syndrome

a severe systemic infection characterized by the presence of bacteria, fungi, viruses, and parasites in the blood, combined with an inflammatory immune response (host response) that may lead to rapid deterioration of the patient’s general condition and possible organ failure.

Septicaemia

 serious systemic infection of the organism by pathogenic germs, indicated by the presence of microorganisms in the blood.

Staphylococcus

 a genus of Gram-positive bacteria, usually observed in clusters resembling bunches of grapes.

Substrate

 a molecule used as a starting product which binds to the active ste of ain enzyme and is converted into one or more products.

Syndromic approach

a medical approach based on the analysis of a syndrome (i.e., a set of symptoms and/or clinical signs) to identify, in a single test, the pathogen(s) responsible for this syndrome, whether viral, bacterial, fungal, or parasitic in origin.

Theranostics

 the association of a diagnostic test with a therapy. The foundation of personalized medicine.

Venous thrombosis

 a method which can help in the assessment of the compatibility between two individuals, their organs, tissues or blood. A technique used to characterize bacteria.

Virus

 a rudimentary infectious microorganism, containing a single type of nucleic acid encaged in a protein capsid, which uses the materials of the cell that it parasitizes to synthesize its own constituents. It reproduces using just its own genetic material.