Bacteria

Exploring Bacteria Bacteria exists almost everywhere you can think of. There are thousands of types of bacteria, most of which are completely harmless to humans. There are species of bacteria that are harmful while others are harmless. Bacteria are simple organisms that consist of one cell. They are among the smallest living things on earth. Bacteria can also be beneficial. For example, certain kinds of bacteria live in the intestines of humans and animals. These forms of bacteria are essential in the digestion process. They help the digestion process by eliminating and destroying harmful organisms. Intestinal bacteria also produce some vitamins needed by our bodies like folic acid and B-12. Then there are harmful bacteria that cause diseases to humans, animals and plants. The diseases affecting humans include: pneumonia, tuberculosis, and bronchitis. These harmful types of bacteria enter the body through natural openings, such as the nose, mouth, and even breaks or cracks in the skin. In addition to the transfer of bacteria through natural openings, bacteria is also transferred from one person to another by means of food, water, and air. These bacteria prevent the body from functioning properly by destroying healthy cells. Certain bacteria produce poisons which cause such diseases such as diphtheria, tetanus, and scarlet fever. Some poisons are produced by living bacteria while others are released only after bacteria dies. For example, a form of food poisoning called botulism is caused by poisons from bacteria in improperly canned foods. Bacteria that may, otherwise, live harmlessly in the body can also cause infections. However, the infections are only minor compared to poison- producing bacteria. An example of this would be if bacteria in the throat of a person with low immunity, reproduces faster than that person’s body can dispose of them. The result is an infection which is known as a sore throat. As stated earlier, bacteria also cause diseases in animals as well as plants. Anthrax is a bacterial disease that infects many animals, especially cattle and sheep which usually contract it from contaminated soil. Plant diseases caused by bacteria include fire blight, which occurs mainly in apple and pear trees, and soft rot, which decays some fruits and vegetables. Bacteria also cause growths called crown galls, which attack various plants. Many bacteria live on the skin, in the mouth, in the intestines, and even in our breathing passages. But the rest of the body tissues are normally free of bacteria. The skin, and the membranes that line the digestive and respiratory systems, prevent most harmful bacteria from entering the body. If harmful bacteria does enter the body, white blood cells surround and attack the bacteria. In addition to the white blood cells, our blood also produces antibodies to fight against infection too. Toxins produced by bacteria are neutralized by certain antibodies called antitoxins. Sometimes the body cannot make its own antitoxins fast enough. In such cases, a physician may inject an antitoxin from an animal, such as a horse or rabbit into you to supplement the deficiency of your body to produce antitoxins. Dead or weakened bacteria are used in making drugs called vaccines, which can prevent the diseases caused by those species of bacteria. These vaccines are injected into the body, which cause the blood to produce antibodies to fight bacteria. Some vaccines protect the body from several years or longer. Drugs called antibiotics are made from microorganisms that inhabit the air, soil, and water. Antibiotics can kill or weaken disease causing bacteria. However, excess use of antibiotics may encourage the spread of bacteria resistant to the drugs. The drugs then become ineffective. People use chemicals called antiseptics to prevent bacteria from growing on living tissues such as our skin. Other chemicals, such as disinfectants, are used to destroy bacteria in water and on such items of clothing and utensils. Bacteria can also be killed by heat; thus, heat is used to sterilize food and utensils. Bacteria can also have odor. For example, when we sweat, bacteria from our skin consumes the sweat, known as apocrine and eccrine, which produces what is commonly known as body odor. Fortunately, deodorants can mask the odor until a shower or bath is available.