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, pathogene
any agent that can cause disease
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005


Any agent capable of causing disease. The term pathogen is usually restricted to living agents, which include viruses, rickettsia, bacteria, fungi, yeasts, protozoa, helminths, and certain insect larval stages. See Disease

Pathogenicity is the ability of an organism to enter a host and cause disease. The degree of pathogenicity, that is, the comparative ability to cause disease, is known as virulence. The terms pathogenic and nonpathogenic refer to the relative virulence of the organism or its ability to cause disease under certain conditions. This ability depends not only upon the properties of the organism but also upon the ability of the host to defend itself (its immunity) and prevent injury. The concept of pathogenicity and virulence has no meaning without reference to a specific host. For example, gonococcus is capable of causing gonorrhea in humans but not in lower animals. See Medical mycology, Medical parasitology, Plant pathology, Plant viruses and viroids, Virulence

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.


A disease-producing agent; usually refers to living organisms.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Where this tick exists, it is an important vector of human and animal disease agents. In China and Japan, it transmits the severe fever with thrombocytopenia syndrome virus (SFTSV), which causes a human hemorrhagic fever (2), and Rickettsia japonica, which causes Japanese spotted fever (3).
Because the disease agents convey from water sources to ponds.
And finally, the artificial constructs created by genetic engineering are designed to cross species barriers and to jump into genomes, to further enhance and speed up horizontal gene transfer and recombination, now acknowledged to be the major route to creating new disease agents, and possibly much more important than point mutations which change isolated bases in the DNA.
Last summer, University of California (UC) scientists identified the disease agent as a yet unnamed species of Phytophthora.
We may tend to think that each disease has a name and that a disease agent must be found to correspond with it.
Yet Sick Building Syndrome (SBS) is not only caused by a disease agent. The basic mechanism is the presence of an abnormally high concentration of a chemical or biological agent that may be a normal part of the indoor environment.
Miss Johnston, aged 29, who lives near Cheadle, Staffs, is one of six people involved in a test case at the High Court in London to claim damages for the psychiatric illness they say they have developed as a result of being told they may be incubating th e Creutzfeld Jakob Disease agent.
* Field tests (2 to 3 years) where candidate quarantine material is grafted to an "indicator" plant which readily exhibits characteristic disease symptoms if the suspected disease agent is present;
This Genalysis platform will combine the ability to sequence the DNA of the infectious organism, in a sealed microchip based system, direct from clinical specimen, with analysis that enables actionable identification of the disease agent within a few hours, a key requirement in the effective treatment of infectious diseases.
The project is called project called Midas (Models of Infectious Disease Agent Study).
Although vaccines are not available to stop all forms of BRD they should reduce the impact and make cases easier to deal with, except when a new disease agent arrives on the farm.
Vaccines wage their wars under the radar, priming immune systems to fight a disease agent that is quickly quashed if it ever does invade.