Pathogenic

Pathogenic refers to something capable of causing disease in its host. A pathogen may also be referred to as an infectious agent, or simply a germ.

The term pathogen came into use in the 1880s. Typically, the term is used to describe an infectious microorganism or agent, such as a virus, bacterium, protozoan, prion, viroid, or fungus. Small animals, such as certain kinds of worms and insect larvae, can also be pathogens. An organism's potential to cause disease is called its pathogenicity.

Types of Pathogens

Pathogens can be classified into several broad categories: Bacteria, Viruses, Fungi, and Parasites.

Bacteria

Bacteria are single-celled microorganisms that can exist independently, symbiotically (in cooperation with another organism) or parasitically (causing harm to another organism). Bacterial pathogens are responsible for diseases such as tuberculosis, pneumonia, and anthrax.

Viruses

Viruses are small infectious agents that can only replicate inside the living cells of an organism. Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea. They’re responsible for a variety of diseases, including AIDS, Ebola, and the common cold.

Fungi

Fungi can cause diseases such as ringworm, athlete's foot, and yeast infection.

Parasites

Parasites live on or in a host organism and get food or other benefits from it. Parasitic diseases can affect practically all living organisms, including plants and mammals. Diseases caused by parasites include malaria, sleeping sickness, and leishmaniasis.

Pathogenicity

Pathogenicity is the ability of a pathogen to produce an infectious disease in an organism. This can be influenced by the genetic makeup of the organism and the pathogen, the location in the host's body that the pathogen targets, and environmental conditions.

See Also

• Infection
• Disease
• Epidemiology
• Microbiology
• Parasitology
• Virology

Pathogenic Resources
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