Bacterial Infections: Overview

Bacteria are tiny single-celled microbes that can infect the body. Some bacterial infections can be quite dangerous and worsen quickly, although they are not always so. Common types of bacterial infections include ear infections, throat infections, bacterial pneumonia, and many, many other types. Treatment often involves drugs in the class called “antibiotics” such as penicillin, erythromycin, and many other types of antibiotics, which may be given as pills or sometimes by injections or other administration routes. Bacterial diseases are different from other categories of disease such as viruses, fungal infections, parasites, and other categories. Bacterial diseases are often contagious, but all such diseases and not in all cases.

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Bacterial diseases continue to present a major threat to human health. Tuberculosis, for instance, ranks among the world's leading causes of death. Streptococcus (Group B Streptococcus), another bacterium, continues to be a frequent cause of life-threatening infection during the first two months of life. Foodborne and waterborne bacteria such as Salmonella and Campylobacter are responsible for a recent troubling increase in diarrheal disease. Meanwhile, during the last decade, scientists discovered many new organisms and new strains of many familiar bacteria, such as Escherichia coli. Such emerging bacterial diseases present a clear challenge to biomedical researchers.

The complexity of this challenge is becoming even clearer as researchers begin to appreciate the many unsuspected mechanisms that bacteria have for causing trouble to human beings. For example, gene transfer among different strains of bacteria, and even between different species of bacteria, is now understood to be a common means whereby these organisms acquire resistance to antibiotics. Basic research has also discovered that some bacteria may play a major role in certain chronic diseases not formerly associated with bacterial infection. The bacterium Helicobacter pylori, for example, has been found to cause ulcers and may contribute to stomach cancer; Guillain Barré syndrome has been associated with prior diarrheal disease caused by Campylobacter jejuni.

Source: NIAID (NIH)1

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Bacteria are living things that have only one cell. Under a microscope, they look like balls, rods, or spirals. They are so small that a line of 1,000 could fit across a pencil eraser. Most bacteria won't hurt you - less than 1 percent of the different types make people sick. Many are helpful. Some bacteria help to digest food, destroy disease-causing cells, and give the body needed vitamins. Bacteria are also used in making healthy foods like yogurt and cheese.

But infectious bacteria can make you ill. They reproduce quickly in your body. Many give off chemicals called toxins, which can damage tissue and make you sick. Examples of bacteria that cause infections include Streptococcus, Staphylococcus, and E. coli.

Antibiotics are the usual treatment. When you take antibiotics, follow the directions carefully. Each time you take antibiotics, you increase the chances that bacteria in your body will learn to resist them causing antibiotic resistance. Later, you could get or spread an infection that those antibiotics cannot cure.

NIH: National Institute of Allergy and Infectious Diseases

Source: MedLinePlus (NIH)2

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About bacteria

Bacteria are microscopic organisms that are too small to see with the naked eye. We all have lots of bacteria living in our bodies. The human body has both good bacteria (like bacteria that help you digest food and protect you from infection) and bad bacteria (the bacteria that cause diseases).

Bacteria can cause many different infections, like urinary tract infections, pneumonia, blood poisoning, skin infections and diarrhoea. Not all infections will need to be treated with antibiotics, your doctor will prescribe antibiotics only when you need to take them.

Source: New Zealand Health3

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Bacterial Infections: An acute infectious disorder that is caused by gram positive or gram negative bacteria; representative examples include pneumococcal, streptococcal, salmonella, and meningeal infections.4

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Bacterial Capsules: An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.5

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Bacterial Infections: An infection adverse event that results in detrimental colonization of a host organism by bacteria6

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Bacterial Infections: Infections by bacteria, general or unspecified.7

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References

  1. Source: NIAID (NIH): niaid.nih.gov/ topics/ bacterialinfections/ Pages/ default.aspx
  2. Source: MedLinePlus (NIH): medlineplus.gov/ bacterialinfections.html
  3. Source: New Zealand Health: health.govt.nz/ your-health/ conditions-and-treatments/ treatments-and-surgery/ medications/ antibiotic-resistance
  4. Source: NCI Thesaurus
  5. Source: MeSH (U.S. National Library of Medicine)
  6. Source: OAE Ontology
  7. Source: Monarch Initiative

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Note: This site is for informational purposes only and is not medical advice. See your doctor or other qualified medical professional for all your medical needs.