plants animals Microbes are small living plants or animals most of which are not visible to the naked eye. diseaseinfection Some microbes cause disease or infection. “good” organisms Many microbes are “good” organisms that help keep balance in the environment and the body.
What microbes lack in size, they make up in number. On the average human, there are about 100 trillion microbes.
Good vs. Bad Microorganisms: Microorganisms that cause disease (germs) are referred to as pathogens. Yeah, I’m bad.
Microorganisms that are harmless or beneficial are called nonpathogens.
Most microbes are considered beneficial or harmless. 87% beneficial organisms 10% opportunists Pathogens 3%
The role of good microorganisms Marine & freshwater microbes form the basis of the food chain in oceans, lakes, and rivers.
Humans and other animals depend on bacteria in their intestines for digestion and synthesis of vitamins including: vitamin B (for metabolism) vitamin K (for blood clotting)
Microorganisms have many commercial applications They are used in synthesis of chemical products such as: acetone enzymes alcohol organic acids many drugs
They are used in the food industry for producing: vinegar pickles cheese green olives alcoholic beverages yogurt bread
Main Classes of Pathogenic Organisms: 1)Bacteria simple one-celled organisms At home within “climate” of human body compose largest group of pathogens 2)Fungi: yeasts & molds Plant-like organisms that live on dead organic matter Grow best in dark, damp places
3) Viruses - smallest microbes acellular particles (not a complete cell) 4) Protozoa one-celled animals often found in decayed materials & contaminated water 5) Helminths parasitic worms caused by larval & egg infestations
Loa loa being extracted from under conjunctivia.
Hydatid cyst formed by tiny tapeworm that migrated to brain.
Summary Microbes are microscopic organisms About 100 trillion microbes live on the average human “Bad” microbes are pathogens About 3% of microorganisms are pathogenic Main classes of pathogenic microbes include: bacteria, fungi, viruses, protoza, & helminths