Antibiotics microbiological

Coeffet-Le Gal, M.F., Thurston, L., Rich, P. et al. (2006) Complementation of daptomycin dpt A and dptD deletion mutations in trans and production of hybrid lipopeptide antibiotics. Microbiology (Reading, England), 152,2993. 

Szczepanowski R, Linke B, Krahn I et al (2009) Detection of 140 clinically relevant antibiotic-resistance genes in the plasmid metagenome of waste water treatment plant bacteria showing reduced susceptibility to selected antibiotics. Microbiology 155 (Pt 7) 2306-2319... 

Robertson GT, Bonventre EJ, Doyle TB, Du Q, Duncan L, Morris TW, Roche ED, Yan D, Lynch AS. (2008) In vitro evaluation of CBR-2092, a novel rifamycin-quinolone hybrid antibiotic Microbiology profiling studies with Staphylococci and Streptococci. Antimicrob Agents Chemother 52 2324-2334. 

Pojer F, Li SM, Heide L (2002) Molecular cloning and sequence analysis of the clorobiocin biosynthetic gene cluster new insights into the biosynthesis of aminocoumarin antibiotics. Microbiology-Sgm 148 3901-3911... 

Marecek and colleagues developed a new electrochemical method for the rapid quantitative analysis of the antibiotic monensin in the fermentation vats used during its production. The standard method for the analysis, which is based on a test for microbiological activity, is both difficult and time-consuming. As part of the study, samples taken at different times from a fermentation production vat were analyzed for the concentration of monensin using both the electrochemical and microbiological procedures. The results, in parts per thousand (ppt), are reported in the following table. 

Antibiotics were used in folk medicine at least as early as 2500 years ago when the Chinese reported the medicinally beneficial effects of moldy bean curd. Evidence for some type of tetracycline antibiotic usage by the Sudanese-Nubian civilization (350 AD) was reported in 1980 (6). Fluorescent areas in human bones from this eta were observed that were identical in location and characteristics to modern bone from patients treated with tetracyclines. Identification of tetracycline in the ancient bones was further substantiated by fluorescence spectmm measurements and microbiological inhibition studies (7). 

T. Koizybski, Z. Kowszyk-Gindifei, and W. Kmylowicz, Antibiotics Origin, JSSature, and Properties, American Society foi Microbiology, Washington,... 

Neutral salts and aqueous solutions of various acids generally follow the acid action. Aluminum has no apparent action or microbiological processes (i.e., the production of antibiotics by deep-vessel fermentation). Fermentation tanks, as well as various absorbing and extracting units, can be made from aluminum. 

Figure 6.4 Stylised representation of changing parameters and penicillin production in cultures of Penldlllum notatum, grown as a surface culture on Czapek-Dox medium (adapted from Hockenhull DJ-D "Production of Antibiotics by Fermentation in Essays in Applied Microbiology edited by Norris J R Richmond M H 1981. John Wiley Sons Ltd Chichester).

The commercial production of penicillin and other antibiotics are the most dramatic in industrial microbiology. The annual production of bulk penicillin is about 33 thousand metric tonnes with annual sales market of more than US 400 million.8 The worldwide bulk sales of the four most important groups of antibiotics, penicillins, cephalosporins, tetracyclines and erythromycin, are US 4.2 billion per annum.10... 

Pharmaceutical microbiology may be defined as that part of microbiology which has a special bearing on pharmacy in all its aspects. This will range fiom the manufacture and quality control of pharmaceutical products to an understanding of the mode of action of antibiotics. The full extent of microbiology on the pharmaceutical area may be judged fiom the chapter contents. 

Acute pharyngitis presents a diagnostic and therapeutic dilemma. The majority of sore throats are caused by a variety of viruses fewer than 20% are bacterial and hence potentially responsive to antibiotic therapy. However, antibiotics are widely prescribed and this reflects the difficulty in discriminating streptococcal from non-streptococcal infections clinically in the absence of microbiological documentation. Nonetheless, Strep, pyogenes is the most important bacterial pathogen and this responds to oral penicillin. However, up to 10 days treatment is required for its eradication fixm the throat. This requirement causes problems with compliance since symptomatic improvement generally occurs within 2-3 days. 

Antibiotics may be assayed by a variety of methods (see Chapter 8, pages 166-188, in Pharmaceutical Microbiology, 5th edition 1992). Only microbiological and radio-enzymatic assays will be considered briefly here see Figs 25.5 and 25.6 and sections 4.1.1 and4.1.2. 

In the commonest form of microbiological assay used today, samples to be assayed are applied in some form of reservoir (porcelain cup, paper dise or well) to a thin layer of agar seeded with indicator organism. The drug diffuses into the medium and after incubation a zone of growth inhibition forms, in this case as a circle around the reservoir. All other factors being constant, the diameter of the zone of inhibition is, within limits, related to the concentration of antibiotic in the reservoir. 

In this context, a multidisciplinary approach (phytochemical -I- synthetic -l-microbiological -i- pharmacological) aimed at evaluating the effectiveness of different 0-heterocyclic structures should be emphasized and encouraged, also in view of the evidence reporting the existence of synergistic effects among these compounds with currently used antibiotic compounds. 

The potencies of some antibiotics described in the European Pharmacopoeia are determined by microbiological assay (Microbiological Assay of Antibiotics 2.7.2... 

The procedure employed for the establishment of the chemical reference substances used in these assays has been previously published (Sandrin et al. 1997). The CRSs for the microbiological assays of antibiotics are first submitted to the chemical tests of the monograph. If the results are satisfactory, a collaborative microbiological assay is carried out, using the International Standard as calibrator. Thus, these reference substances are considered to be secondary reference substances since they are calibrated against existing standards. Potency is expressed in International Units. If an International Standard does not exist, European Pharmacopoeia Units are used. 

Fig. 5-9 Decision tree used to accept or reject results from collaborative trials to establish the potencies of antibiotics to be used as chemical reference substances for microbiological assay standards.

Sandrin J, Daas AGJ and Charton E (1997) Establishment of reference substances for the microbiological assay of antibiotics. Pharmeuropa 9 327-330. 

Bergeron, M. G. Ouellette, M. Preventing antibiotic resistance through rapid genotypic identification of bacteria and of their antibiotic resistance genes in the clinical microbiology laboratory. J. Clin. Microbiol. 1998, 36, 2169-2172. 

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