Cancer

Pathogens find safe harbor deep in the gastric glands

Scientists have long tried to understand how pathogenic bacteria like Helicobacter pylori, a risk factor for stomach ulcers and cancer, survive in the harsh environment of the stomach. In a new study publishing May 2 in the ...

Diseases, Conditions, Syndromes

Scientists discover how superbugs hide from their host

New research led by the University of Sheffield has discovered how a hospital superbug evades the immune system to cause infection – paving the way for new treatments.

Diabetes

Researchers identify trigger and mechanism in type 1 diabetes

Researchers at National Jewish Health have identified an elusive trigger of type 1 diabetes. A protein fragment formed in the pancreas activates the immune system's T cells, leading them to attack and destroy beta cells, ...

Medical research

Against gut instinct

By turning a pathogenic yeast into an immunity-conferring symbiont, a team of A*STAR researchers is unraveling mysteries behind gut evolution and universal vaccines

Diseases, Conditions, Syndromes

Exploring copper's potential as antibiotic

Pneumonia starts like this: A bacterial cell called Streptococcus pneumoniae enters the nostril. It travels down the nasal passage and into the lungs, where a war begins. In the lungs, S. pneumoniae encounters immune cells ...

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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