Antibiotic resistance among Escherichia coli urinary isolates and their susceptibility to clove essential oil

Escherichia coli is a Gram-negative, facultatively anaerobic, rod-shaped, coliform bacterium, which is a primary cause of urinary tract infections. Resistance to antibiotics has become a particular problem in recent decades. Consequently, there is an unmet need for new therapeutic options. It has been observed that essential oils have bactericidal effects. The antimicrobial susceptibility testing for Escherichia coli isolates obtained from urine of patients with urinary tract infections was determined via disk diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST, 2015). Essential oil from clove – Syzygium aromaticum (L.) Merill et L.M. (Myrtaceae) was analyzed by GC-FID-MS. Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) were detected by using the micro-dilution broth method. Escherichia coli clinical isolates are characterized by high resistance to ampicillin, amoxicillin with clavulanic acid, norfloxacin, trimethoprim/sulfamethoxazole, tetracycline, tobramycin and ticarcillin. Clove oil possesses strong inhibiting and killing properties against E. coli isolates, among them the ones resistant to recommended antibiotics. The results of this study highlight the need for testing the efficacy of new agents to inactivate bacteria in clinical settings

Ginsenoside content in suspension cultures of Panax quinquefolium L. cultivated in shake flasksand stirred-tank bioreactor

Plant suspension cultures are described as a source for the acquisition of medicinal secondary metabolites which in the future may become an alternative to traditional raw materials. This study demonstrates that the cell cultures of one of the ginseng species – Panax quinquefolium L. synthesize ginsenosides, which are triterpene saponins having a multidirectional pharmacological effects. Tested suspension cultures were run on a small scale in the shake flasksand in scale up of the process in a 10-liter stirred tank. In the shake flasks,the highest biomass yield (2.28 gl-1 for dry and 33.99 gl-1 for fresh weight) was reached on day 30 of culture, and the highest content of saponins (2.66 mg g -1 dw) was determined on day 28 of culture. In the bioreactor, nearly 2.67 and 3-fold increase of respectively dry and fresh biomass was recorded in relation to the inoculum. Large-scale cultures synthesized protopanaxatriol derivatives such as Rg1 and Re ginsenosides, however, no saponins belonging to the protopanaxadiol derivatives were reported

Structural Basis for Substrate Specificity in Human Monomeric Carbonyl Reductases

Carbonyl reduction constitutes a phase I reaction for many xenobiotics and is carried out in mammals mainly by members of two protein families, namely aldo-keto reductases and short-chain dehydrogenases/reductases. In addition to their capacity to reduce xenobiotics, several of the enzymes act on endogenous compounds such as steroids or eicosanoids. One of the major carbonyl reducing enzymes found in humans is carbonyl reductase 1 (CBR1) with a very broad substrate spectrum. A paralog, carbonyl reductase 3 (CBR3) has about 70% sequence identity and has not been sufficiently characterized to date. Screening of a focused xenobiotic compound library revealed that CBR3 has narrower substrate specificity and acts on several orthoquinones, as well as isatin or the anticancer drug oracin. To further investigate structure-activity relationships between these enzymes we crystallized CBR3, performed substrate docking, site-directed mutagenesis and compared its kinetic features to CBR1. Despite high sequence similarities, the active sites differ in shape and surface properties. The data reveal that the differences in substrate specificity are largely due to a short segment of a substrate binding loop comprising critical residues Trp229/Pro230, Ala235/Asp236 as well as part of the active site formed by Met141/Gln142 in CBR1 and CBR3, respectively. The data suggest a minor role in xenobiotic metabolism for CBR3. ENHANCED VERSION: This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available in Text S1

The Increase of Triterpene Saponin Production Induced by Trans-Anethole in Hairy Root Cultures of Panax quinquefolium

In vitro cultivation is an effective way to increase pharmaceutical production. To increase ginsenoside production in hairy root cultures of American ginseng, the present study uses trans-anethole as an elicitor. The content of nine triterpene saponins was determined: Rb1, Rb2, Rb3, Rc, Rd, Rg1, Rg2, Re and Rf. Trans-anethole was found to stimulate saponin synthesis regardless of exposure time (24 and 72 h). Twenty-four hour exposure to 1 μmol trans-anethole in the culture medium resulted in the highest increase of total saponin content (twice that of untreated roots), and optimum accumulation of Rb-group saponins, with ginsenoside Rc dominating (8.45 mg g−1 d.w.). In contrast, the highest mean content of protopanaxatriol derivatives was obtained for 10 μmol trans-anethole. The Re metabolite predominated, reaching a concentration of 5.72 mg g−1 d.w.: a 3.9-fold increase over untreated roots. Elicitation with use of trans-anethole can therefore be an effective method of increasing ginsenoside production in shake flasks

Panax quinquefolium hairy root extracts and their effect in connections with antibiotics against pathogenic bacteria – preliminary study

 The aim of the present study was to determine the level of ginsenosides in extracts from hairy root A, B, G clones of Panax quinquefolium and their action with antibiotics against clinical bacterial isolates. The content of ginsenosides (the key biologically active compounds) were determined in tested extracts using HPLC. The activity of extracts with antibiotics was established by micro-dilution broth method. Total triterpene saponin content was 14.68, 14.32 and 10.07 mgg-1 d.w. for root culture clones B, A and G, respectively. Our research indicates that the addition of extracts mainly from B and G clone hairy root cultures to antibiotics allow to reduce the ampicillin and tetracycline effective concentration respectively against Enterococcus faecalis and both Escherichia coli and Acintobacter baumannii

Model do badań elastooptycznych opis patentowy nr 57883 /

Tyt. z ekranu tyt.Zgłoszono 2 maja 1968 r.Opublikowano 30 sierpnia 1969 r.Numer zgłosz. P 126740Dostępny także w wersji drukowanej.Tryb dostępu: Internet