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The bacteria generally enter through a break in the skin, such as a cut or puncture wound caused by a contaminated object. [1] [3] They produce toxins that interfere with normal muscle contractions. [4] Diagnosis is based on the presenting signs and symptoms. The disease does not spread between people. [1]
Pathogenic bacteria are bacteria that can cause disease. [1] This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number of these pathogenic species in humans is estimated to be fewer than a hundred. [2]
Bacteria toxins which can be classified as either exotoxins or endotoxins.Exotoxins are generated and actively secreted; endotoxins remain part of the bacteria. Usually, an endotoxin is part of the bacterial outer membrane, and it is not released until the bacterium is killed by the immune system.
The human strains of Ebola virus, for example, incapacitate those infected extremely quickly and kill them soon after. As a result, those affected by this disease do not have the opportunity to travel very far from the initial infection zone. [70] Also, this virus must spread through skin lesions or permeable membranes such as the eye.
Bacteria inside the granuloma can become dormant, resulting in latent infection. Another feature of the granulomas is the development of abnormal cell death ( necrosis ) in the center of tubercles . To the naked eye, this has the texture of soft, white cheese and is termed caseous necrosis .
Some species of bacteria kill and then consume other microorganisms; these species are called predatory bacteria. [198] These include organisms such as Myxococcus xanthus , which forms swarms of cells that kill and digest any bacteria they encounter. [ 199 ]
Along with some strains of Clostridium butyricum and Clostridium baratii, these bacteria all produce the toxin. [2] Botulinum toxin can cause botulism, a severe flaccid paralytic disease in humans and other animals, [3] and is the most potent toxin known to science, natural or synthetic, with a lethal dose of 1.3–2.1 ng/kg in humans. [4] [5]
The bacteria also evades macrophage-killing by neutralizing reactive nitrogen intermediates. [20] More recently, M. tuberculosis has been shown to secrete and cover itself in 1-tuberculosinyladenosine (1-TbAd), a special nucleoside that acts as an antacid , allowing it to neutralize pH and induce swelling in lysosomes.