Pioneering diagnostics

Glossary of Scientific Terms

A

Acute coronary syndrome: decreased blood flow in the coronary arteries resulting in reduced circulation rate and inadequate oxygenation of the myocardial muscle.

Amplification: a technique, usually using enzymes, for multiplying nucleic acids in order to increase the sensitivity of detection methods.

Antibiotic susceptibility testing: determines the growth of a bacterium in the presence of antibiotics and classifies it as susceptible, resistant or intermediate.

Antibiotic: a substance of natural or synthetic origin capable of stopping the multiplication of bacteria.

Antibody: a molecule produced by the immune system to detect and neutralize pathogens, in particular viruses.

Antigens: a foreign substance in an organism which triggers the production of an antibody (immune reaction).

B

Bacterium: a unicellular microorganism lacking chlorophyll and visible only under a microscope. Bacteria do not belong to either the plant or the animal kingdom.

Biochemistry: an area of science which studies the correlation between the structure of natural molecules and the consequences for their activity.

Biomarker / marker: any indicator (nucleic acids, enzymes, metabolites and other types of molecules: histamines, hormones, proteins, etc.) present in the body or excreted by it as a biological response to a physiological or pathological
condition. A biomarker can make it possible to identify the presence, the effect and/or the measurement of specific phenomena, such as:
   • the rapid or early detection of a disease, before the first symptoms appear,
   • the progression of a disease,
   • the impact of a drug or treatment.

Blood culture: an essential blood test in infectious diseases. It is carried out by taking a sample of venous blood, which is then cultured to reveal the presence or absence of germs.

C

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 continuously colonized by commensal bacteria that do not cause disease unless the subject is weakened.

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.

D

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.

E

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 bacterial resistance 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.

F

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.

G

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

Gram staining: staining which reveals the properties of the bacterial wall so that they can be used to distinguish and classify bacteria. The main distinction is between Gram-positive and Gram-negative bacteria.

H

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.

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.

I

Immunoassays: detection of infectious agents (bacteria, viruses, parasites) and pathogen markers based on an antigen/antibody reaction.

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.

IVD: abbreviation for in vitro diagnostics.

L

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.

M

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 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. bioMérieux uses culture-based microbiology methods for the growth of bacteria from biological fluids, food and pharmaceutical samples. 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 can detect a bacterium, virus, yeast, parasite or a biomarker through the presence of DNA or RNA genetic sequences in a sample.

MRSA: methicillin-resistant Staphylococcus aureus bacterium.

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

Multi-resistant bacteria: bacteria are said to be multi-resistant to antibiotics when they are sensitive only to a small number of the antibiotics customarily used in therapy, as a consequence of the accumulation of natural and acquired resistances.

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

Healthcare-Associated Infections: a disease contracted in a hospital or other healthcare establishment by a patient who did not have this disease on admission.

N

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.

O

Oncology (or cancerology): the medical specialty of the study, diagnosis and treatment of cancers.

P

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

Pathogen: that which causes or can cause disease.

Phage recombinant protein: bacteriophage tail protein that has been obtained by a biological process. Bacteriophages: highly specific viruses that only infect bacteria. They are used for the targeted capture of bacteria and to isolate them
from a sample.

POC (point-of-care) - POCT (point-of-care testing): services offered “at the bedside”, including in particular the analysis of the diagnosis.

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.

Q

Quality indicator: term used in food processing to define the microorganisms responsible for visual or taste alterations (e.g., mold or bacterial contamination). Quality indicator counts are used to assess product hygiene.

R

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).

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.

S

Sepsis: a widespread infection characterized by the presence of bacteria in the bloodstream (viruses or fungi can also cause sepsis) and the deterioration of the patient’s general condition as a result of the infection (host response).

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 site of an enzyme and is converted into one or more products.

T

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

Typing: 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.

V

Venous thrombosis: the formation of a blood clot in a vein. It usually occurs in a vein of the lower limbs, in the leg or hip, rarely in the upper limbs.

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.