Mayyada Farhan Darwees
This study aimed to investigated the prevalence and resistance pattern of different Citrobacter species phenotypically and genotypically to β-lactam and some most common antibiotics then evaluate the antibacterial activity of omega-3 extracted from flaxseed against isolates that harboring resistance genes. 19 Citrobacter isolates were isolated from100 stool and urine samples taken from patients attended to AL-Sadar Hospital during June-December 2016. Clinical samples were cultured on specific media, thereafter isolates were identified depending on morphological, biochemical characteristics and VITK-2. The results showed that the Citrobacter comprise 24% of isolated bacteria which divided into 11 (14.1%) were C. freundii, 5 (6.41%) C. kosaeri and C. farmeri were 3 (3.8%). The antagonistic activity was evaluated by observing a clear zone of inhibition growth, the results showed that all Citrobacter (100%) isolates were resistant to Ampicillin, cefoxitin and sensitive to Imipinim, also the isolates showed different degrees of resistant to β-lactam antibiotics initially. By confirmatory test the results observed 17/19 (89.4%) isolated were ESBL producers finally using PCR technique to detect bla–genes (blaCTX-M, OXA, SHV and Z). The results revealed that 14/17 (82.3) of potential ESBL producing Citrobacter were harbor one or more of ESBL genes they included 10 of C. freundii and 4 of C. koseri. The extraction of essential fatty acid semicarbazide (omega-3) from Linum usitatissium (Flax seed) were tested to evaluate their activity against resistant isolates, results explained broad spectrum antibacterial property of EFASC compounds against resistant bacteria. In conclusion, this study found increase prevalence of MDR Citrobacter spp as causative agents in clinical cases. Considering antibacterial activity of EFASC, it was observed highly activity against resistant pathogens deservedly, therefore attention must be paid to development their used as alternative antibiotics.
Božena Šerá and Milan Kobes
Slender speedwell (Veronica filiformis Smith, family Plantaginaceae) is a non-native and invasive species of grassland in the Europe. The aim of the study was to test the ability of the growth and spreading in nine differently managed grasslands (mowing, mulching, grazing). The best survival was found in two-years mowed lots with fertilisation and in all lots with not permanent cattle pasture crops. There were found the highest number of survived plants and plants with big “rosette“ diameters. Number of survived plant for two seasons was 18 and total number of vegetative peaks per plant was 688. The potential for the spreading of such plant population is great. On the other hand, plants did not survived in lots with mulch treatment and in fenced lots with permanent cattle grazing.
Alok Dhaundiyal and Suraj Bhan Singh
This paper studied the implementation of fuzzy logic on the relevant parameter of biomass pyrolysis. Frequency factor, the upper limit of ‘dE’, and the scale parameter of Rayleigh distribution are fuzzified in order to estimate the randomness in estimating the parametric values. Distribution function, f(E), of activation energies is assumed to follow the Rayleigh distribution. Thermo-analytical data has been found experimentally with the help of TGA/DTG analysis. The approximated solution of distributed activation energy model (DAEM) is obtained by using asymptotic approach.
Microalgae are unicellular free living entities and therefore their responses to excess of heavy metals must be faster and more efficient than those in vascular plants protected by various types of tissues. Up to date, numerous studies reported metal bioaccumulation potential of algae but metabolic responses have relatively rarely been monitored. Here I provide basic overview of quantitative changes of ascorbic acid (AA), reduced glutathione (GSH), phytochelatins (PCs) and selected related enzymes (ascorbate peroxidase and glutathione reductase) in some common microalgae exposed to various metals (cadmium mainly). Despite various culture and exposure conditions, some common signs of metal toxicity (including e.g. enhancement of phytochelatin biosynthesis) are clearly identifiable in algae. Other metal chelators such as organic acids are also briefly mentioned. Comparison with macroalgae, mosses and vascular plants is discussed in terms of basal values and evolutionary similarities.
Matej Remenár, Edita Karelová, Jana Harichová, Anna Kamlárová, Kristína Krčová, Marcel Zámocký and Peter Ferianc
In this study we aimed to analyse the structure and diversity of overall bacterial community and its resistance determinants from nickel-contaminated soil in Slovakia by both, cultivation-dependent and independent approaches. The phylogeny was reconstructed using partial sequences of 16S rRNA (16S rDNA) and heavy-metal resistance genes from separated isolates and bacterial clones. A total of 518 bacterial sequences obtained from both, isolates and clones, represented 266 species belonging to 8 bacterial phyla: Acidobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, Gemmatimonadetes, Proteobacteria (α-, β- and γ-classes), Verrucomicrobia, and one yet unclassified group. In addition, among isolates and clones, 49 different nccA-like genes were found in the final output. Majority of them were assigned to a system of transmembrane metal pumps. Our results demonstrate the fact that the nickel-contaminated soil is able to present very specific heavy-metal resistant bacterial community which can be used in different bioremediation processes.
Matúš Peško, Marianna Molnárová and Agáta Fargašová
Presented study evaluates effects of various Sb(III) concentrations on tomato plants (Solanum lycopersicum) cultivated hydroponically. Visual symptoms of antimony toxicity were observed only at two highest applied concentrations (50 and 100 mg/L). Dry weight of aboveground parts decreased significantly in variants treated with 25, 50 and 100 mg/L Sb(III), by ~12, 35 and 65 %, respectively, in comparison to the control. Statistically significant decrease of chlorophyll a and b was observed only after application of two highest studied concentrations 50 and 100 mg/L Sb(III). On the other hand concentration of total carotenoids in leaves rose with increasing external Sb(III) concentration. High concentrations (50 and 100 mg/L) of Sb(III) in nutrient solution caused that protein content in leaves dropped by ~20 and 39% relative to control. Accumulation of antimony in roots was about 5- (10 mg/L) to 27-times (25 mg/L) greater than that in shoots. The highest BAF factor value determined for shoots was ~55 at 10 mg/L Sb(III) and for roots it was ~821 at 50 mg/L Sb(III). Translocation factor values were in whole studied concentration range 5 – 100 mg/L Sb(III) < 1. The most effective translocation of antimony from roots to shoots was observes for variants treated with 10 mg/L of Sb(III).
Rudolf Masarovič, Martina Zvaríková, Jakub Sigmund and Peter Fedor
Exotic species introduction has recently increased European insect diversity in accordance with global climate change and international biological commodity trade, often with serious environmental and economic consequences for natural ecosystems as well as urban and farmland area. This short communication deals with the first official faunistic record of the gladiolus thrips Thrips simplex (Morison, 1930) (Thysanoptera, Thripidae) in Slovakia.
Purpose of this paper is to draft shot information about framework for ecological risk assessment compile according Guidelines and short description of phases from which this method consists. During description of particular procedures, the meaning of used terms is introduced and explained. The framework for risk assessment is presented as a useful tool for risk management and selection of available cleanup and remedy technologies, and costs of alternative actions.