Bacterial spectrum

In cases of ocular trauma, Bacillus species are the most common cause of postoperative infection, particularly in a rural setting (6,10-12). Staphylococcal organisms are the next most common while gram-negative infections have an increased likelihood by comparison to postoperative cases. Mixed infections involving multiple bacteria are also more common than after elective surgery (5,6,13). 

Bleb-related endophthalmitis is caused by streptococcal infection approximately half of the time and Hemophilus influenza is seen more commonly than after postcataract infections (14,15). The cause of endogenous endophthalmitis depends on the population studied. Staphylococcus and Streptococcus are frequent bacterial causes. Candida septicemia is frequently found in hospitalized patients. 

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Agents used to treat nosocomial infections in the intensive care unit (e.g., expanded gram-negative bacterial spectrum) should not be routinely used to treat community-acquired infections. 

Chemical characterization hypothesizes that certain molecules are unique and representative of individual microorganisms, and therefore the mass spectra can be characteristic of given species. A typical bacterial spectrum obtained by MALDI-TOF usually contains between 20 and 40 large peaks, mainly produced by proteins, phospholipids, and cyclic lipopeptides, in the MW range of 4—20 kDa.31 ESI is less frequently used samples containing intact cells can clog electrospray devices, and the formation of multiply charged species complicates the spectra. 

Two main approaches have been used to interpret bacterial mass spectra. First, pattern recognition methods have been used, in which reference spectra are obtained under standardized conditions to generate a fingerprint collection. An unknown bacterial spectrum obtained under the same conditions is then compared to the collection and matched if possible. 

Penicillins are P-Iactam antimicrobials, which have a 4-membered P-Iactam ring that is fused to a 5-mem-bered thiazolidine ring, thus forming the penam nucleus (Figure 1). Modifications of the parent compound can alter the bacterial spectrum of these P-... 

Clinical evaluation in dental plaque control U. P. Saxer el aL. J. Clin. Periodontol. 9, 162 (1982). In vitro anti -bacterial spectrum M. Cortat. P. Fels. Anneimittel-Forsch. 37, 463 (1987). Clinical evaluation in pharyngeal infections M. A. Weibel et aL. ibid. 467. 

As suggested above, most research during the 1970s was devoted to preparing cephalosporins with an expanded antibacterial spectrum. Even so, several derivatives described during this period with a cephalothin-like bacterial spectrum of activity are worthy of note. 

There are several methods of preparation of antibacterial quinolones, drugs widely used in the therapy of various bacterial diseases. The most general method is based on the nucleophilic cyclization of 2-halobenzoyl derivatives 402, leading to the key intermediates 403. The methodology is exemplified in Scheme 63 by the synthesis of a broad-spectrum drug ciprofloxacin... 

Chloramphenicol, a powerful antibiotic isolated in 1949 from the Streptomyces venezuelae bacterium, is active against a broad spectrum of bacterial infections and is particularly valuable against typhoid fever. Assign R,S configurations to the chirality centers in chloramphenicol. 

Fig. 2.4 The spectrum of bacterial luminescence measured with B. harveyi luciferase, FMN, tetradecanal and NADH, in 50 mM phosphate buffer, pH 7.0, at 0°C (dashed line from Matheson et al., 1981) and the absorption and fluorescence emission spectra of LumP (solid lines) and Rf-LumP (dotted lines) obtained from P. leiog-natbi, in 25 mM phosphate buffer, pH 7.0, containing 1 mM EDTA and 10 mM 2-mercaptoethanol, at room temperature (from Petushkov et al, 2000, with permission from Elsevier). LumP is a lumazine protein, and Rf-LumP contains riboflavin instead of lumazine in the lumazine protein. Fluorescence emission curves are at the right side of the absorption curves.

Eckstein, J. W., et al. (1990). A time-dependent bacterial bioluminescence emission spectrum in an in vitro single turnover system energy transfer alone cannot account for the yellow emission of Vibrio fischeri Y-l. Proc. Natl. Acad. Sci. USA 87 1466-1470. 

Vervoort, J., et al. (1986). Identification of the true carbon-13 nuclear magnetic resonance spectrum of the stable intermediate II in bacterial luciferase. Biochemistry 25 8062-8067. 

The second distinguishing feature of the Rieske protein apart from its unique EPR spectrum that was recognized early is its high redox potential 91). The redox potentials of Rieske clusters from mitochondrial and bacterial bci complexes are in the range of +265 to + 310 mV (Table XI) the potentials in complexes are even slightly... 

Natural pigment production for food coloration includes the entire spectrum of biotechnologies. For example, biological production of carotenoid pigments has medical implications because carotenoids are nutritive (pro-vitamin A), antioxidant, and photoprotective. Carotenoids are produced alternately in agricultural systems (plants), industrial bioreactors (bacterial and fungi), and marine systems (cyanobacteria and algae). 

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