Where do most bacteria live?

Most bacteria are saprophytes which means that they live on dead organic material which is found in soil or water. Around 50 types of bacteria are pathogenic, and some are highly virulent, Bacteria needs specific types of environments for growth such as energy sources, water, protection from UV light, suitable PH levels and the correct temperature. There are good types of bacteria which live inside the human body which help to fight infections and disease. This is known as natural flora or commensals. A bacterial infection occurs when pathogens enter the tissue of the host which triggers a response. Infection can be identified by red, swollen and pus-filled sites on the host. However, colonization can occur where little or no response to the pathogen is detected. Colonization is usually the precursor to infectious breakouts, and cross-infection can occur even if signs and symptoms are not visible in the original patient.

When bacteria reproduce by binary fission where the single bacterium cell divides into two ‘daughter’ cells which are a clone of the ‘parent’ cells. When the conditions are right for bacterial reproduction, some bacteria like Escherichia coli can divide rapidly and spread within a few hours. Some bacteria can adopt a survival mechanism known as endospores which are dormant structures that are highly resistant to certain chemical and physical conditions, such as heat, UV light, and disinfectants. This makes it more difficult to destroy them. Anthrax (caused my bacillus anthracis) is an example of an endospore-producing bacteria which is a contagious pathogen.