Intracellular bacteria

Enzymatic digestion lysozyme 0.2 mg/ml, 37 °C, 15 mins. bacteria intracellular proteins lab scale only, often combined with mechanical disruption... 

Figure 22-6 represents a general scheme of the development of human CD4 Thl cells. Typically, there is Thl polarization when antigenic stimulation is caused by a virus or intracellular bacteria (intracellular pathogen) followed by antigenic presentation from specialized cells such as dendritic cells, with a high production of IFNa and IL-12. The activation of NK cells then creates a high concentration of IFNy without an increase in levels of IL-4. Thus an environ-... 

Polyesters are known to be produced by many bacteria as intracellular reserve materials for use as a food source during periods of environmental stress. They have received a great deal of attention since the 1970s because they are biodegradable, can be processed as plastic materials, are produced from renewable resources, and can be produced by many bacteria in a range of compositions. The thermoplastic polymers have properties that vary from soft elastomers to rigid brittie plastics in accordance with the stmcture of the pendent side-chain of the polyester. The general stmcture of this class of compounds is shown by (3), where R = CH3, n = >100, and m = 0-8. 

Even the plasma membranes of prokaryotic cells (bacteria) are complex (Figure 9.1). With no intracellular organelles to divide and organize the work, bacteria carry out processes either at the plasma membrane or in the cyto-... 

Cisplatin was discovered fortuitously by observing that bacteria present in electrolysis solutions could not divide. It is hypothesized that in the intracellular environment, a chloride is lost and replaced by a water molecule. The resulting species is an efficient bifunctional interactor with DNA, forming platinum-based cross-links similar to that formed by alkylating agents. 

Furthermore, the inability of the drug to reach the focus of the infection or to reach bacteria with intracellular location may be a common reason for the failure of antibiotic treatment. 

PHAs are produced by the bacteria to store carbon and energy reserves (Keshavarz, Roy, 2010). Previous works stated that an intracellular accumulation of PHAs improves the survival of general bacteria under environmental stress conditions (Kadouri et al., 2005 Zhao et al., 2007). Various microorganisms are produced in different properties of biopolymer depending on the types of microorganisms and carbon sources used. More than 150 different monomers can be combined within this family to give materials with extremely different properties (Chen Wu, 2005). 

Many bacterial polysaccharides contain phosphoric ester groups. There is a limited number of examples of monoesters. More common are phosphoric diesters, connecting an amino alcohol or an alditol to the polysaccharide chain. Another possibility is that oligosaccharide or oligosaccharide-alditol repeating units are connected to a polymer by phosphoric diester linkages. In addition to the intracellular teichoic acids, several bacteria, for example, different types of Streptococcus pneumoniae, elaborate extracellular polymers of this type. These polymers are generally discussed in connection with the bacterial polysaccharides. 

The process of activation of neutrophils is essentially similar. They are activated, via specific receptors, by interaction with bacteria, binding of chemotactic factors, or antibody-antigen complexes. The resultant rise in intracellular Ca affects many processes in neutrophils, such as assembly of micrombules and the actin-myosin system. These processes are respectively involved in secretion of contents of granules and in motility, which enables neutrophils to seek out the invaders. The activated neutrophils are now ready to destroy the invaders by mechanisms that include production of active derivatives of oxygen. 

Fig. 9.1 Schematic representation of possible mechanisms of resistance in Gram-negative and Gram-positive bacteria. 1, antibiotic-inactivating enzymes 2, antibiotic efflux proteins 3, alteration or duplication of intracellular targets 4, alteration of the cell membrane reducing antibiotic uptake 5, alterations in porins or lipopolysaccharide reducing antibiotic uptake or binding.

Mycobacteria are more resistant than other non-sporulating bacteria to a wide range of biocides. Examples of such organisms axe Mycobacterium tuberculosis, theM avium-intracellulare (MAI) group andM. chelonae (M. chelonei). Of the bacteria, however, the most resistant of all to biocides are bacterial spores, e.g. Bacillus subtilis, B. cereus. 

Catechins Bacteria Tetracycline efflnx pinnp 8-lactams Increased intracellular retention of tetracycline [66]... 

Many bacteria possess a high-affinity urea uptake system accompanied by an intracellular urease enzyme (135). Nielsen et al. (136) have measured both natural urea turnover rates and gross N mineralization rates in situ using a new... 

V. Bianciotto, C. Bandi, D. Minerdi, M. Sironi, H. V. Tichy, and P. Bonfante, An obligately endosymbiotic fungus it.self harbors obligately intracellular bacteria. Applied Environ. Microbiol. 62 3005 (1996). 

Figure 4 Stabilized bromine antimicrobials are produced by eosinophils, a type of mammalian white blood cell. Bacteria are captured by phagocytosis and contained intracellularly within vesicles called phagosomes. Granules release cationic surfactants, lytic enzymes, and eosinophil peroxidase into the phagosome in a process known as degranulation. Eosinophil peroxidase, an enzyme that is structurally similar to the bromoperoxidases found in seaweed (Figure I), selectively catalyzes oxidation of bromide to hypobromite by reducing hydrogen peroxide to water. The hypobromite immediately reacts with nitrogenous stabilizers such as aminoethanesulfonic acid (taurine) to form more effective and less toxic antimicrobial agents.

The identification of bacteria has traditionally required the establishment of a pure culture before any other steps are taken. Pure cultures of bacteria may sometimes be obtained from blood and spinal fluid, which are normally sterile, or from extreme environments like hot springs. However, because there are few such situations in nature, individual bacteria must generally be isolated from other cells and grown for one to five days to obtain pure cultures before identification. Some pathogenic bacteria are obligate intracellular parasites that are difficult or impossible to grow outside their mammalian host cells 37 for these, pure cultures are not feasible. 

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