About Pathogens

Pathogens are infectious or disease-causing agents. Bacteria, for example, are microorganisms that can enter the human body and cause disease, as can viruses; fungi, like ringworm, are also pathogenic. Pathogens enter the body every day, through the air, food, water, or because of contact with other people. The immune system destroys many of these infectious microorganisms, but when it cannot, the person is infected and contracts a disease. If the body cannot rid itself of the pathogen, antibiotics and other drugs may be used.

Bacteria

• Bacteria come in many shapes and sizes, including rods, spirals and spheres, can be found nearly everywhere and are needed to break down nutrients. Infectious bacteria that cause disease are, in fact, pathogenic. Bacteria do not commonly kill their hosts, but greatly weaken them; however, these forms of bacteria cannot spread as easily as others. Anthrax, Escherichia coli, salmonella, and the Streptococcus species are all examples of bacteria.

Virus

• Viruses are a different type of pathogen, classified as something between a living and nonliving organism. Viruses are smaller than bacteria. Essentially protein coats carrying genetic information in the form of DNA or RNA, viruses attack cells, multiplying rapidly by using elements of the host cell. When critical mass is reached, the viral matter ruptures the cell, effectively killing it, and the new copies go on to infect other cells. Smallpox, the common cold, influenza, herpes and HIV are all examples of viruses.

Fungus

• Fungi are eukaryotic micro organisms, and require organic nutrition to survive. Most live off dead organic matter. Fungi that attack humans are opportunistic, attacking the body when it is weakened either by other infections, open wounds or AIDS. Fungal pathogens can attack the skin or hair and cause superficial infections; more dangerous fungi attack vital organs and the nervous system, which can often be fatal. Ringworm and jock itch are examples of fungi.

Useful Pathogens

• Pathogens do not just attack human hosts; other creatures, like insects, can be infected by bacteria, viruses and fungi as well. These types of infections can be important forms of pest control. Spraying equipment that use these control measures are referred to as microbial insecticides. Because of the nature of pathogens, these insecticides only eliminate certain species of insects, and are non-toxic to human and wildlife. However, microbial insecticides lack the killing power of chemical insecticides.

Drugs

• Antibiotics are some of the most effective medication in modern medicine. Although antibiotics can only be used against bacteria, their effectiveness and reliability at killing them is unsurpassed. For viruses, vaccines are used to help prevent viral infection. A vaccine exposes the body to weakened viral strains, which the body can then easily fight. The immune system builds up a resistance by creating antibodies to the pathogen so when it is attacked again, the body is prepared.