Immunology

T cells found to require rest and maintenance

T cells, biology textbooks teach us, are the soldiers of the immune system, constantly on the ready to respond to a variety of threats, from viruses to tumors. However, without rest and maintenance T cells can die and leave ...

Diseases, Conditions, Syndromes

Dynamics of adaptive immunity in tuberculosis uncovered

Unlike other infectious diseases that affect the lungs, the immune response to fight tuberculosis (TB) infections develops at least twice as slowly. Until recently, the dynamic interplay between bacteria and the host's immune ...

Oncology & Cancer

Orally administered tumor vaccine shows promise in animal models

In a study published in Nature Biomedical Engineering, a research team led by Prof. Nie Guangjun and Prof. Zhao Xiao at National Center for Nanoscience and Technology (NCNST) of the Chinese Academy of Sciences demonstrated ...

Diseases, Conditions, Syndromes

Machine-learning model can distinguish antibody targets

A new study shows that it is possible to use the genetic sequences of a person's antibodies to predict what pathogens those antibodies will target. Reported in the journal Immunity, the new approach successfully differentiates ...

Diseases, Conditions, Syndromes

Sanitizing device kills SARS-CoV-2 virus in 60 seconds

A new made-in-Alberta sanitization product aimed at stopping the spread of SARS-CoV-2 will soon be in use at the Edmonton International Airport and government offices in Calgary and Edmonton, thanks to a partnership with ...

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Pathogen

A pathogen (from Greek πάθος path "suffering, passion", and γἰγνομαι (γεν-) gignomai (gen-) "I give birth to"), infectious agent, or (more commonly) germ, is a biological agent that causes disease or illness to its host. There are several substrates and pathways whereby pathogens can invade a host; the principal pathways have different episodic time frames, but soil contamination has the longest or most persistent potential for harboring a pathogen.

The body contains many natural defenses against some of the common pathogens (such as Pneumocystis) in the form of the human immune system and by some "helpful" bacteria present in the human body's normal flora. However, if the immune system or "good" bacteria is damaged in any way (such as by chemotherapy, human immunodeficiency virus (HIV), or antibiotics being taken to kill other pathogens), pathogenic bacteria that were being held at bay can proliferate and cause harm to the host. Such cases are called opportunistic infection.

Some pathogens (such as the bacterium Yersinia pestis, which may have caused the Black Plague, the Variola virus, and the Maleria protozoa) have been responsible for massive numbers of casualties and have had numerous effects on afflicted groups. Of particular note in modern times is HIV, which is known to have infected several million humans globally, along with the Influenza virus. Today, while many medical advances have been made to safeguard against infection by pathogens, through the use of vaccination, antibiotics, and fungicide, pathogens continue to threaten human life. Social advances such as food safety, hygiene, and water treatment have reduced the threat from some pathogens.

Not all pathogens are negative. In entomology, pathogens are one of the "Three P's" (predators, pathogens, and parasitoids) that serve as natural or introduced biological controls to suppress arthropod pest populations.

This text uses material from Wikipedia, licensed under CC BY-SA