Chromosomal Integration of Huge and Complex blaNDM-Carrying Genetic Elements in Enterobacteriaceae

In this study, a detailed genetic dissection of the huge and complex blaNDM-carrying genetic elements and their related mobile genetic elements was performed in Enterobacteriaceae. An extensive comparison was applied to 12 chromosomal genetic elements, including six sequenced in this study and the other six from GenBank. These 12 genetic elements were divided into five groups: a novel IME Tn6588; two related IMEs Tn6523 (SGI1) and Tn6589; four related ICEs Tn6512 (R391), Tn6575 (ICEPvuChnBC22), Tn6576, and Tn6577; Tn7 and its derivatives Tn6726 and 40.7-kb Tn7-related element; and two related IMEs Tn6591 (GIsul2) and Tn6590. At least 51 resistance genes, involved in resistance to 18 different categories of antibiotics and heavy metals, were found in these 12 genetic elements. Notably, Tn6576 carried another ICE Tn6582. In particular, the six blaNDM-carrying genetic elements Tn6588, Tn6589, Tn6575, Tn6576, Tn6726, and 40.7-kb Tn7-related element contained large accessory multidrug resistance (MDR) regions, each of which had a very complex mosaic structure that comprised intact or residual mobile genetic elements including insertion sequences, unit or composite transposons, integrons, and putative resistance units. Core blaNDM genetic environments manifested as four different Tn125 derivatives and, notably, two or more copies of relevant Tn125 derivatives were found in each of Tn6576, Tn6588, Tn6589, and 40.7-kb Tn7-related element. The huge and complex blaNDM-carrying genetic elements were assembled from complex transposition and homolog recombination. Firstly identified were eight novel mobile elements, including three ICEs Tn6576, Tn6577, and Tn6582, two IMEs, Tn6588 and Tn6589, two composite transposons Tn6580a and Tn6580b, and one integron In1718.

Enhanced Weathering and related element fluxes – a cropland mesocosm approach

The weathering of silicates is a major control on atmospheric CO2 at geologic timescales. It was proposed to enhance this process to actively remove CO2 from the atmosphere. While there are some studies that propose and theoretically analyze the application of rock powder to agricultural land, results from field experiments are still scarce. In order to evaluate the efficiency and side effects of Enhanced Weathering (EW), a mesocosm experiment was set up and agricultural soil from Belgium was amended with olivine-bearing dunite ground to two different grain sizes, while distinguishing setups with and without crops. Based on measurements of Mg, Si, pH, and DIC, the additional weathering effect of olivine could be confirmed. Calculated weathering rates are up to 3 orders of magnitude lower than found in other studies. The calculated CO2 consumption by weathering based on the outlet water of the mesocosm systems was low with 2.3–4.9 tCO2km-2a-1 if compared with previous theoretical estimates. Suspected causes were the removal or dilution of Mg as a weathering product by processes like adsorption, mineralization, plant uptake, evapotranspiration, and/or preferential flow, not specifically addressed in previous EW experiments for CO2 consumption. The observation that Mg concentrations in the upper soil layers were about 1 order of magnitude higher than in the outlet water indicates that a careful tracking of weathering indicators like Mg in the field is essential for a precise estimate of the CO2 consumption potential of EW, specifically under global deployment scenarios with a high diversity of ecosystem settings. Porewater Mg∕Si molar ratios suggest that dissolved Si is reprecipitating, forming a cation-depleted Si layer on the reactive mineral surface of freshly ground rocks. The release of potentially harmful trace elements is an acknowledged side effect of EW. Primarily Ni and Cr are elevated in the soil solution, while Ni concentrations exceed the limits of drinking water quality. The use of olivine, rich in Ni and Cr, is not recommended, and alternative rock sources are suggested for the application.

Analyzing and Investigating the Effect of Nailing on Stabilization Soil Trenches of Sand with Medium Density via Analytical Limit

Pit stability in urban areas is one of the great problems of enforcement operations. A variety of methods have been devised to fixate and stabilize slopes and pits that Nailing is an example of them that is used in urban areas. In this study, stability of pit has been analyzed using this method and using the S-Nail software that the analysis has been done with limit equilibrium method. In order to investigate the effect of stabilization Nail element in sandy soil with medium density, in both dry and moist conditions, a number of used variables related to soil strength parameters such as C and φ and a number used variable of related element such as the length of the Nail, are horizontal distance of elements from each other, grid or density were considered. So the effect of each variable in the soil stabilization has been obtained and resulting in proposing optimal scheme of the considered soil stabilization.

EL PAPEL DE LA INFORMACIÓN EN LA CONFIGURACIÓN DE LA GOBERNANZA AMBIENTAL

El estudio de la gobernanza ambiental permite comprender la problemática pesquera. Aunque la información es relevante como elemento de poder, ha sido escasamente abordada en los estudios sobre gobernanza. Al estudiar el papel de la información en la «configuración política» ambiental en una zona pesquera de un área natural protegida de Chiapas, con datos obtenidos por medio de metodologías cualitativas, se observó que la población pesquera carece de información sobre la regulación ambiental y los derechos y obligaciones respectivos. Este hecho limita la participación ciudadana y la toma de decisiones. Todo ello dificulta la construcción de estrategias para la búsqueda de soluciones ante la problemática ambiental. ROLE PLAYED BY INFORMATION IN THE CONFIGURATION OF ENVIRONMENTAL GOVERNANCE The study of environmental governance allows for an understanding of issues related to fishing. Although information is relevant as a power-related element, governance studies have hardly addressed it. By studying the role information plays in the «political configuration» of environmental issues in a fishing zone of a natural protected area in Chiapas State, with data obtained through qualitative methodologies, it was observed that the fishing population lacks information regarding environmental regulation and their corresponding rights and obligations. This limits citizen participation and decisionmaking. All this hinders the construction of strategies to seek for solutions to environmental issues.

Resistance Determinants and Their Association with Different Transposons in the Antibiotic-ResistantStreptococcus pneumoniae

Multiple resistance ofStreptococcus pneumoniaeis generally associated with their unique recombination-mediated genetic plasticity and possessing the mobile genetic elements. The aim of our study was to detect antibiotic resistance determinants and conjugative transposons in 138 antibiotic-resistant pneumococcal strains isolated from nasopharynx of healthy young children from Lublin, Poland. These strains resistant to tetracycline and/or to chloramphenicol/erythromycin/clindamycin were tested by PCR using the specific genes as markers. The presence of Tn916family transposons, carryingtet(M) andint/xisTn916, was observed in all of the tested strains. Tn916was detected in 16 strains resistant only to tetracycline. Tn6002and Tn3872-related element were found among 99erm(B)-carrying strains (83.8% and 3.0%, resp.). Eight strains harbouringmef(E) anderm(B) genes were detected, suggesting the presence of Tn2010and Tn2017transposons. Among 101 chloramphenicol-resistant strains, two variants of Tn5252-related transposon were distinguished depending on the presence ofint/xis5252genes specific forcatgene-containing Tn5252(75.2% of strains) orintSp23FST81gene, specific forcat-containing ICESp23FST81 element (24.8% of strains). In 6 strains Tn916-like and Tn5252-like elements formed a Tn5253-like structure. Besides clonal dissemination of resistant strains of pneumococci in the population, horizontal transfer of conjugative transposons is an important factor of the high prevalence of antibiotic resistance.