A puncture wound on the finger caused by a prick from rusted barbed wire may result in tetanus due to infection by spores of the bacterium Clostridium tetani.
The spores live mainly in soil and manure, but are also found on dirty or rusting metal objects. If untreated, tetanus lockjaw may be fatal. Microbes that cause disease are called pathogens. Find out which microbe is responsible for malaria!
An infection can be seen as a battle between the invading pathogens and host. How does the immune system work? Homepage Why Microbiology Matters What is microbiology? Microbes and the human body Routes of transmission. Routes of transmission The spreading of microbes is called transmission. Transmission involves the following stages: Escape from the host or reservoir of infection where the infectious agent normally lives and multiplies. Transport to the new host. Entry to the new host.
Escape from the new host. The main routes of transmission are listed below. Person-to-person Touch A cold can be caught by shaking the hand of a person who has a cold and who has just used their hand to wipe their dripping nose.
Transmission by fomites non-living objects such as barbed wire. The National Academies. How Infection Works. How Pathogens Make Us Sick. Infection occurs when viruses , bacteria , or other microbes enter your body and begin to multiply. Disease occurs when the cells in your body are damaged as a result of infection and signs and symptoms of an illness appear.
The incidence of disease among those infected varies greatly depending on the particular pathogen and individual susceptibility. Many of the symptoms that make a person suffer during an infection—fever, malaise, headache, rash—result from the activities of the immune system trying to eliminate the infection from the body.
In response to infection, your immune system springs into action. White blood cells , antibodies , and other mechanisms go to work to rid your body of the foreign invader. Antigens are proteins that are found on the surface of the pathogen. Antigens are unique to that pathogen. The whooping cough bacterium, for example, will have different antigens on its surface from the TB bacterium.
When an antigen enters the body, the immune system produces antibodies against it. Antibodies are always Y-shaped. It is like a battle with the army antibody fighting off the invader antigen. A type of white blood cell called a lymphocyte recognises the antigen as being foreign and produces antibodies that are specific to that antigen.
Each antibody has a unique binding site shape which locks onto the specific shape of the antigen. The antibodies destroy the antigen pathogen which is then engulfed and digested by macrophages. White blood cells can also produce chemicals called antitoxins which destroy the toxins poisons some bacteria produce when they have invaded the body.
Tetanus, diphtheria and scarlet fever are all diseases where the bacteria secrete toxins. The memory cells remember the microbe which caused the disease and rapidly make the correct antibody if the body is exposed to infection again. The pathogen is quickly destroyed preventing symptoms of the disease occurring.
Microbes that cause disease are called pathogens. Find out which microbe is responsible for malaria! Homepage Why Microbiology Matters What is microbiology? Microbes and the human body Immune system.
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