For an explanation, see the main splats page
SPLATS about bacterial diseases
The principles of bacterial diseases
- In some systems, the prokaryotic Monera make up one of the five main groups of living things, including the bacteria, the cyanobacteria and the Archaea.
- Bacteria are usually small cells that live and reproduce independently or in small colonies, and which have no separate membrane-bound organelles or nucleus.
- Bacteria can usually only be seen with a microscope, although at least one bacterium, Thiomargarita namibiensis, is large enough to be seen with the naked eye.
- Bacteria can be distinguished by staining properties, which show up when stains are used that are either taken up by chemicals in the cell wall, or not.
- In 1884, Christian Joachim Gram invented his Gram stain which could be used for the classification of bacteria, because it only stained one type of cell wall.
- One common stain used on bacteria is the Gram stain, used to divide bacteria in Gram positive (which take on a violet colour) and Gram negative bacteria.
- The cell wall of a Gram negative bacterium is high in lipid content and low in peptidoglycans, the portion that the Gram stain normally attaches to.
- Some bacteria form biofilms, layers of bacteria and complex molecules, often with other species involved, which behave like tissues in higher animals.
- Bacteria form plaques of biofilm, complex interdependent communities of bacteria that interact and form layers similar to tissues in higher animals.
- Some bacteria may be cultured in a Petri dish on a culture medium, but there are many more, perhaps as much as 96%, which cannot be cultured.
- Most of the bacteria that cannot be cultured in a pure culture are those involved in biofilms, and which require other bacteria to be present before they grow.
- Bubonic plague is a bacterial disease. The rats carry bacteria, fleas get them when they bite rats, and transfer them to humans when they bite the humans.
- In 1843, Oliver Wendell Holmes observed the contagiousness of septicaemia, and suggested that medical staff should wash their hands to prevent its spread.
- Ignaz Semmelweis could not explain why his innovative method designed to prevent childbed fever worked, though there could be no doubt that it did in fact work.
- Semmelweis required those working under him to wash their hands in strong chemicals (chlorinated lime) before touching patients, and the fever rates plummeted.
- Semmelweis died of the same fever he had done so much to fight, just a few years before the tide turned when Pasteur and Lister showed that his ideas worked.
- In 1854, John Snow showed that whatever caused cholera, it could be found in the unboiled water from one well in London's Soho, coming close to a germ theory.
- Hermann von Helmholtz anticipated Louis Pasteur by indicating that both fermentation and rotting were biological effects, but he did not follow this up.
- In 1863, Pasteur showed that a micro-organism causes the souring of wine into vinegar, and as a response, invented pasteurization to kill the micro-organisms.
- Bacteria can be killed in an autoclave if they are exposed for long enough to the combination of heat and steam, mainly because key proteins are denatured.
- The bacteria that attack humans can generally be cultured, because the culture media that are used for this imitate the human body in many ways.
- In 1882, Robert Koch described his method for isolating bacteria in pure culture by plating them on solid media, first gelatin, then agar later.
- In 1876, Robert Koch cultured anthrax bacilli and showed that anthrax is caused by a specific organism, and in the same year, also stated Koch's postulates.
- Robert Koch developed a set of four postulates, essential conditions that had to be met before an organism could be named as the cause of a particular disease.
- Koch's first postulate: The organism should always be found present in an animal with the disease, and should never be found in one not suffering the disease.
- Koch's second postulate: The organism must be cultured in a pure culture, containing only that one organism, away from the animal body, so it can be isolated.
- Koch's third postulate: When such a culture of the purified organism is inoculated into a susceptible organism, characteristic disease symptoms should appear.
- Koch's fourth postulate: The organisms reisolated and cultured from the experimental animals should be seen to be the same organism that was cultured earlier.
- Even in old age, Florence Nightingale dismissed the 'germ-fetish'. She was one of the most reputable opponents of antisepsis, even as she promoted cleanliness.
- In 1909, Charles Jules Henri Nicolle showed in a series of monkey trials in Tunis that the bacillus of typhus fever was transmitted by the body louse.
- In 1910, Paul Ehrlich and Sachahiro Hata introduced the so-called magic bullet salvarsan to selectively kill the organism responsible for syphilis.
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