Bacterium: single-celled microscopic organisms that lack nuclei and other organized cell structures. “Bacteria” is the plural form of “bacterium.” While several bacterial species are pathogenic (capable of causing disease), many are non-infectious.

Microorganism: an individual form of life that is capable of growing, metabolising nutrients, and reproducing. Organisms can be unicellular or multicellular. They are scientifically divided into five different groups that include prokaryotes, protists, fungi, plants, and animals. A microorganism is an organism of microscopic or sub-microscopic size, such as a bacterium.

Cross contamination: transmission of microorganisms from contaminated materials, surfaces, articles or humans to non-contaminated materials, surfaces etc.

DNA: deoxyreibonucleic acid. A nucleic acid that carries the genetic information in the cell and is capable of self-replication.

Ag Ion (silver ion): a silver ion is a silver atom which has lost one electron and therefore carries a positive charge.

Active substance as defined by the Biocidal Products Regulation: a substance or microorganism including a virus or a fungus having a general or specific action on or against harmful organisms.

Biocidal Product: active substances and preparations containing one or more active substances, put up in the form in which they are supplied to the user, intended to destroy, deter, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism by chemical or biological means.

Biocide: this is an active substance or biocidal product as defined by the Biocidal Products Regulation.

Biofilm: communities of microorganisms attached to a surface. Microorganisms undergo profound changes during their transition from planktonic (free-swimming) organisms to cells that are part of a complex, surface-attached community.

Gram-positive bacteria: these are able to be stained with a special violet/blue stain and therefore show up under the microscope.

Gram-negative bacteria: these bacteria do not retain the violet / blue stain and need to be stained with a special counter-stain, which gives them a pink / red colouration under the microscope.

Escherichia coli: E. coli are Gram-negative rod shaped bacteria. E. coli are a consistent inhabitant of the human intestinal tract. Pathogenic strains of E. coli can be responsible for urinary tract infections, intestinal diseases such as gastroenteritis and neonatal meningitis. E. coli serve as an indicator of faecal contamination of water and can also be found outside the body in contaminated water environments.

Staphylococcus aureus: S. aureus are Gram-positive spherical bacteria which occur in microscopic irregular clusters resembling grapes. S. aureus mainly colonises human nasal passages but can also be found on the skin, mucous membranes such as in the oral cavity and the gastrointestinal tract. They can also be found in soil. S. aureus can cause surgical infection and skin infections. They can also cause skin lesions such as boils and styes and more serious infections such as pneumonia and urinary tract infections.

Klebsiella pneumoniae: K. pneumoniae are Gram-negative rod shaped bacteria. They belong to the normal intestinal flora of man. Most frequent K. pneumoniae infections include lower respiratory tract and catheter-associated urinary tract infections.