Bacteria are bad for me
Bacteria are microscopically small (usually 1 to 2 micrometre in length or diameter), single-celled organisms. There are thousands of different kinds of bacteria on earth and grow in a wide range of environmental conditions. Many are saprophytic, degrading organic material in soil and water or as parasites of animals and plants. Only a few kinds of bacteria cause disease.
The bacteria that cause disease are called pathogenic bacteria. Once in the human body it enters the body through natural openings or broken skin such as the ‘nose, mouth, urethra, anus and vagina are lined with mucous membranes which are moist providing the perfect environment for microbial growth’. In addition to transfer of bacteria through natural openings, a pathogenic bacterium is also passed from one victim to another in several ways.
Diseases can be transmitted by direct contact from one infected individual to another. The mucous membranes lining the nose and mouth and genital tracts are thinner and softer than most outer surfaces so they are the most frequent entry points, though several organisms infect through the skin. Direct contact is the main means of transfer for most sexually transmitted diseases. These pathogens include Neisseria gonorrhoeae (gonorrhoea) and Treponema pallidum (syphilis), which are extremely sensitive to the effects of environmental factors. They are therefore unable to live outside of their human host.
Organisms that live on the skin surface enter through broken skin and start an opportunistic, cause disease when the body's defence system is impaired, infection. For instance, staphylococci living on the skin may infect tissues to cause boils or occasionally septicaemia. Tetanus bacteria live in the soil, degrading dead organic material, but dirt can carry spores into deep wounds, or they can enter via an animal bite.
The most important vectors are insects, including biting flies and bugs that transfer pathogens as they feed...