Explorative Randomized Phase II Clinical Study of the Efficacy and Safety of Finafloxacin versus Ciprofloxacin for Treatment of Complicated Urinary Tract Infections.

The broad-spectrum C-8-cyano-fluoroquinolone finafloxacin displays enhanced activity under acidic conditions. This phase II clinical study compared the efficacies and safeties of finafloxacin and ciprofloxacin in patients with complicated urinary tract infection and/or pyelonephritis. A 5-day regimen with 800 mg finafloxacin once a day (q.d.) (FINA05) had results similar to those of a 10-day regimen with 800 mg finafloxacin q.d. (FINA10). Combined microbiological and clinical responses at the test-of-cure (TOC) visit were 70% for FINA05, 68% for FINA10, and 57% for a 10-day ciprofloxacin regimen (CIPRO10) in 193 patients (64 for FINA05, 68 for FINA10, and 61 for CIPRO10) of the microbiological intent-to-treat (mITT) population. Additionally, the clinical effects of ciprofloxacin on patients with an acidic urine pH (80% of patients) were reduced, whereas the effects of finafloxacin were unchanged. Finafloxacin was safe and well tolerated. Overall, 43.4% of the patients in the FINA05 group, 42.7% in the FINA10 group, and 54.2% in the CIPRO10 group experienced mostly mild and treatment-emergent but unrelated adverse events. A short-course regimen of 5 days of finafloxacin resulted in high eradication and improved clinical outcome rates compared to those for treatment with ciprofloxacin for 10 days. In contrast to those of ciprofloxacin, the clinical effects of finafloxacin were not reduced by acidic urine pH. Hospitalized adults were randomized 1:1:1 to finafloxacin treatment (800 mg q.d.) for either 5 or 10 days or to ciprofloxacin treatment (400 mg/500 mg b.i.d.) for 10 days with an optional switch from intravenous (i.v.) to oral administration at day 3. The primary endpoint was the combined microbiological and clinical response at the TOC visit in the microbiological intent-to-treat population. (This study has been registered at ClinicalTrials.gov under identifier NCT01928433.).

Insights about the biosynthesis of the avermectin deoxysugar L-oleandrose through heterologous expression of Streptomyces avermitilis deoxysugar genes in Streptomyces lividans.

BACKGROUND: The avermectins, produced by Streptomyces avermitilis, are potent anthelminthic agents with a polyketide-derived macrolide skeleton linked to a disaccharide composed of two alpha-linked L-oleandrose units. Eight contiguous genes, avrBCDEFGHI (also called aveBI-BVIII), are located within the avermectin-producing gene cluster and have previously been mapped to the biosynthesis and attachment of thymidinediphospho-oleandrose to the avermectin aglycone. This gene cassette provides a convenient way to study the biosynthesis of 2,6-dideoxysugars, namely that of L-oleandrose, and to explore ways to alter the biosynthesis and structures of the avermectins by combinatorial biosynthesis. RESULTS: A Streptomyces lividans strain harboring a single plasmid with the avrBCDEFGHI genes in which avrBEDC and avrIHGF were expressed under control of the actI and actIII promoters, respectively, correctly glycosylated exogenous avermectin A1a aglycone with identical oleandrose units to yield avermectin A1a. Modified versions of this minimal gene set produced novel mono- and disaccharide avermectins. The results provide further insight into the biosynthesis of L-oleandrose. CONCLUSIONS: The plasmid-based reconstruction of the avr deoxysugar genes for expression in a heterologous system combined with biotransformation has led to new information about the mechanism of 2,6-deoxysugar biosynthesis. The structures of the di-demethyldeoxysugar avermectins accumulated indicate that in the oleandrose pathway the stereochemistry at C-3 is ultimately determined by the 3-O-methyltransferase and not by the 3-ketoreductase or a possible 3,5-epimerase. The AvrF protein is therefore a 5-epimerase and not a 3,5-epimerase. The ability of the AvrB (mono-)glycosyltransferase to accommodate different deoxysugar intermediates is evident from the structures of the novel avermectins produced.

3D culture model of fibroblast-mediated collagen creep to identify abnormal cell behaviour.

Native collagen gels are important biomimetic cell support scaffolds, and a plastic compression process can now be used to rapidly remove fluid to any required collagen density, producing strong 3D tissue-like models. This study aimed to measure the mechanical creep properties of such scaffolds and to quantify any enhanced creep occurring in the presence of cells (cell-mediated creep). The test rig developed applies constant creep tension during culture and measures real-time extension due to cell action. This was used to model extracellular matrix creep, implicated in the transversalis fascia (TF) in inguinal hernia. Experiments showed that at an applied tension equivalent to 15% break strength, cell-mediated creep over 24-h culture periods was identified at creep rates of 0.46 and 0.38%/h for normal TF and human dermal fibroblasts, respectively. However, hernia TF fibroblasts produced negligible cell-mediated creep levels under the same conditions. Raising the cell culture temperature from 4 to 37 °C was used to demonstrate live cell dependence of this creep. This represents the first in vitro demonstration of TF cell-mediated collagen creep and to our knowledge the first demonstration of a functional, hernia-related cell abnormality.

Production of aromatic minimal polyketides by the daunorubicin polyketide synthase genes reveals the incompatibility of the heterologous DpsY and JadI cyclases.

Our investigations into whether the biosynthesis of a linearly fused ring system of an aromatic polyketide (jadomycin) could be modified to produce an angularly fused system (daunorubicin) and vice versa showed that introduction of the respective cyclases did not have the desired effect. Genes from the daunorubicin pathway produced a novel 21-carbon polyketide.

The structure of mithramycin reinvestigated.

A reinvestigation of the structure of mithramycin, the principal product of Streptomyces argillaceus ATCC 12956, is reported. The structure elucidation was carried out with mithramycin decaacetate (4) using 2D NMR methods, including TOCSY, HMBC, and HSQC experiments. The work resulted in structure 3being confirmed for mithramycin.