# Commission Regulation (EU) No 546/2011 of 10 June 2011 implementing Regulation (EC) No 1107/2009 of the European Parliament and of the Council as regards uniform principles for evaluation and authorisation of plant protection products (Text with EEA relevance), Division 10: Definitions and explanations of microbiological terms

Extent: E+W+S+N.I.

AntibiosisA relationship between two or more species in which one species is actively harmed (as by the production of toxins by the harming species).
AntigenicAny substance that, as a result of coming in contact with appropriate cells, induces a state of sensitivity and/or immune responsiveness after a latent period (days to weeks) and which reacts in a demonstrable way with antibodies and/or immune cells of the sensitised subject in vivo or in vitro.
AntimicrobialAntimicrobial agents or antimicrobial(s) refer to naturally occurring, semi-synthetic or synthetic substances that exhibit antimicrobial activity (kill or inhibit the growth of micro-organisms).
The term antimicrobial(s) includes:
antibiotics, which refer to substances produced by or derived from micro-organisms, and
anticoccidials, which refer to substances that are active against coccidia, single cell protozoan parasites.
CFUColony-forming unit; one or more cells that grow to form a single visible colony.
ColonisationProliferation and persistence of a micro-organism in an environment, such as on external (skin) or internal body surfaces (intestine, lungs). For colonisation, the micro-organism must at least persist for a longer period than expected in a specific organ. The population of micro-organisms may decline but at a slower rate than normal clearance; it may be a steady population or it may be a growing population. Colonisation can be related to harmless and functional micro-organisms as well as to pathogenic micro-organisms. The possible occurrence of effects is not indicated.
Ecological nicheUnique environmental position occupied by a particular species, perceived in terms of actual physical space occupied and function performed within the community or ecosystem.
HostAn animal (including humans) or plant that harbours or nourishes another organism (parasite).
Host specificityThe range of different host-species that can be colonised by a microbial species or strain. A host-specific micro-organism colonises or has adverse effects on one or only a small number of different host-species. A non-host-specific micro-organism might colonise or might have adverse effects on a broad range of different host-species.
InfectionThe introduction or entry of a pathogenic micro-organism into a susceptible host, whether or not it causes pathological effects or disease. The organism must enter the body of the host, usually the cells, and be able to reproduce to form new infective units. Simply ingesting a pathogen does not imply infection.
InfectiveCapable of transmitting an infection.
InfectivityThe characteristics of a micro-organism that allow it to infect a susceptible host.
InvasionThe entry of a micro-organism into the host body (e.g. actual penetration of the integument, gut epithelial cells, etc.). ‘Primary invasiveness’ is a property of pathogenic micro-organisms.
MultiplicationAbility of a micro-organism to reproduce and increase in numbers during an infection.
MycotoxinA fungal toxin.
Non-viable micro-organismA micro-organism that is not capable of replication or of transferring genetic material.
Non-viable residueA residue that is not capable of replication or of transferring genetic material.
PathogenicityThe ability of a micro-organism to cause disease and/or inflict damage on the host. Many pathogens cause disease by a combination of (i) toxicity and invasiveness or (ii) toxicity and colonising ability. However, some invasive pathogens cause disease that results from an abnormal reaction of the host’s defence system.
SymbiosisA type of interaction between organisms where one organism lives in intimate association with another, which is favourable for both organisms.
Viable micro-organismA micro-organism that is capable of replication or of transferring genetic material.
Viable residueA residue that is capable of replication or of transferring genetic material.
ViroidAny of a class of infectious agents consisting of a small strand of RNA not associated with any protein. The RNA does not code for proteins and is not translated; it is replicated by host cell enzymes. Viroids are known to cause several plant diseases.
VirulenceMeasurement of the degree of disease producing ability of a micro-organism as indicated by the severity of the disease produced. Measure of the dosage (inoculum size) required to cause a specific degree of pathogenicity. It is measured experimentally by the median lethal dose (LD50) or median infective dose (ID50).

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Source: https://www.legislation.gov.uk/eur/2011/546/annex/part/II/division/A/division/10 (the official version)
Page: https://openlegislation.uk/eu-regulation-2011-546/annex/part-II/division-A/division-10
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.