Bacteria are important in the production of cheese, butter, yoghurt, sour cream, sauerkraut, pickles, and vinegar. Bacteria are used to process linen and to soften animal hides. Certain antibiotic drugs are obtained from bacteria. The important industrial solvents, acetone, and butyl alcohol are produced by bacterial fermentations.
The primitive microscopic organisms belonging to the lowest division of the plant kingdom, are widely distributed in nature. Bacteria are being found in soil, air, water, on plants and animals. Bacteria exist in environments where few other life forms can maintain themselves, such as hot springs where the temperature reaches 180 °F (82 °C), in the Antarctic Ocean, and in deep oceanic waters where they live under pressures of thousands of pounds per square inch.
Despite their extremely important role to other living organisms and the cycle of organic processes, they are also responsible for many plant, animal, and human diseases. Few events in the history of mankind have been as devastating as the Black Death, or bubonic plague, which swept through Europe in the 14th century (1348 to 1350), killing approximately 25 million people, 30–60 percent of Europe's population. Physicians have been identified a host of ailments as being caused by bacteria, including syphilis, typhoid fever, diphtheria, scarlet fever, diarrhea, and many other.
Exposure to pathogenic (disease-producing) bacteria doesn't guarantee that disease will result. This depends upon particular bacteria involved, the number of organisms that enter the body, and the ability of the body to fight the infection (immunity). Some bacteria are everyday inhabitants of the skin and the intestinal tract. As long as they remain confined to these places they are harmless, however, should they gain entrance to other parts of the body, they are capable of producing serious diseases. Infections of the kidneys (pyelonephiritis) or bladder (cystitis) are caused by bacteria that have escaped from intestinal tract.
Bacteria may produced the symptoms of disease through the effects of bacterial poisons (toxins). These substances may be secreted by the bacteria (exotoxins), or be built into the structure of the bacterial cell (endotoxins). The endotoxins are liberated only upon the death of the cell.
Bacteria are selective in the parts of the body that they choose to invade. The staphylococci infect the skin, producing boils and acne. The streptococci attack the throat. Tuberculosis and pneumonia are caused by organisms that settle in the lungs. Meningitis, an infections of the tissues surrounding the brain, is caused by various organisms, including the meningococcus, pneumococcus, streptococcus, and staphylococcus.
Bacterial endocarditis, bacterial infection of the lining of the heart, particularly of the heart valves. It usually appears in anyone who have previously had rheumatic or congenital heart disease. Treatment is with antibiotic drugs and depends upon the proper identification of the infecting bacteria. Penicilin-resistant organisms may be responsible in some cases and require special selection of antibiotics.
Diseases such as diptheria, tetanus, meningitis, and typhoid can be prevented by immunization, and many other bacterial diseases can be treated by antibiotic drugs. Tuberculosis patients must daily consume of antibiotic drugs for 6 month treatment. Most death from bacterial infections are caused by organisms that have become resistant to the action of antibiotics.
Source Encyclopedia International by :
- Jerard Hurwitz, Professor, Department of Development Biology and Cancer Research, Albert Einstein College of Medicine, New York.
- Jerome D. Waye, M.D., Assistant Clinical Professor of Medicine, Mount Sinai Medicine School; Chief, Division of Gastroenterology, Trafalgar Hospital, New York.
- Irving Solomon, M.D., Assistant Clinical Professor of Medicine, Mount Sinai Medicine School, New York.