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Survival of the host cell is in many cases dependent on the egress strategy of the pathogen. There are many examples documented in various species. The only case I found that's somewhat relevant to human cells was were mutant Legionella pneumophila, defective in the lytic pore complex, did not produce necrosis of the host cell. However, the cells did release ...


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The fermentation is relatively complex, as quite a number of different bacterial species and yeast live in the Kefir grains. These are made of of the polysaccheride kefiran which immobilizes the bacteria (in contrast for example to yoghurt). The microbes live symbiotic on this matrix. According to the references a number of different microorganisms has been ...


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Well essentially the added Lactobacillus species ferment lactose and other sugars to lactic acid, thus lowering the pH of the product (they take up lactose use it as an energy source under anaerobic conditions and secrete lactic acid). This gives the kefir and other fermented milk products their sourness. Also the lower pH prevents many other bacteria from ...


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There are photosynthetic archaea (such as Halobacterium) but the mechanism is different. They use rhodopsin-like ion pumps (bacteriorhodopsin and halorhodopsin) to move ions against the gradient and produce ATP via chemiosmosis (like mitochondria).


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The gram staining relies on the differences in the bacterial membranes. The gram positive bacteria have a thick peptidoglycan layer on top of the cell membrane, the gram negative bacteria have a lipid layer on the outside followed by a thin peptidoglycan layer and then the cell membrane. See the image for clarification (from here): Crytall violet ...


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The Streptococci are a part of the normal human flora. The streptococci are widely distributed in nature and frequently form part of the normal human flora (seeTable 29-1). Approximately 5-15% of humans carry S pyogenes or S agalactiae in the nasopharynx. Please see:http://www.ncbi.nlm.nih.gov/books/NBK7611/#!po=51.4706 for more details on ...



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