Estimating the bias related to DNA recovery from hemp stems for retting microbial community investigation.

The industrial hemp plant Cannabis sativa is a source of vegetable fiber for both textiles and biocomposite applications. After harvesting, the plant stems are laid out on the ground and colonized by microorganisms (bacteria and fungi) naturally present in the soil and on the stems. By producing hydrolytic enzymes that degrade the plant wall polymers, the natural cement that binds the fiber bundles together is removed, thus facilitating their dissociation (retting process) which is required for producing high-performant fibers. To investigate temporal dynamics of retting microbial communities (density levels, diversity, and structure), a reliable protocol for extracting genomic DNA from stems is mandatory. However, very little attention has been paid to the methodological aspects of nucleic acid extraction, although they are crucial for the significance of the final result. Three protocols were selected and tested: a commercial kit (FastDNA™ Spin Kit for soil), the Gns-GII procedure, and a custom procedure from the Genosol platform. A comparative analysis was carried out on soil and two different varieties of hemp stem. The efficiency of each method was measured by evaluating both the quantity and quality of the extracted DNA and the abundance and taxonomy of bacterial and fungal populations. The Genosol protocol provides interesting yields in terms of quantity and quality of genomic DNA compared to the other two protocols. However, no major difference was observed in microbial diversity between the two extraction procedures (FastDNA™ SPIN Kit and Genosol protocol). Based on these results, the FastDNA™ SPIN kit or the Genosol procedure seems to be suitable for studying bacterial and fungal communities of the retting process. It should be noted that this work has demonstrated the importance of evaluating biases associated with DNA recovery from hemp stems. KEY POINTS: • Metagenomic DNA was successfully extracted from hemp stem samples using three different protocols. • Further evaluation was performed in terms of DNA yield and purity, abundance level, and microbial community structure. • This work exhibited the crucial importance of DNA recovery bias evaluation.

Evaluation of Coriolis Micro Air Sampling to Detect Volatile and Semi-Volatile Organic Compounds.

There are several analytical procedures available for the monitoring of volatile organic compounds (VOCs) in the air, which differ mainly on sampling procedures. The Coriolis micro air sampler is a tool normally designed for biological air sampling. In this paper, the Coriolis micro bio collector is used to evaluate its ability to sample organic contaminants sampling and detecting them when combined GC-MS. We also compare the use of the Coriolis micro with a standardized sampling method, which is the use of a lung box with a Nalophan® bag. The results show that the Coriolis micro sampling method is suitable for the sampling of organic contaminants. Indeed, the Coriolis micro allows to sample and detect mainly semi-volatile molecules, while the lung box/Nalophan® bags allow to sample more volatile molecules (highly volatile and volatile). These results were confirmed in the controlled air lab with a slight difference with the field. The simultaneous use of the both techniques allow to sample and detect a larger number of molecules with specific physicochemical properties to each sampling technique. In conclusion, the Coriolis micro can sample and detect volatile organic compounds present in air. We have shown that the development of alternative sampling methods and the use of non-target analysis are essential for a more comprehensive risk assessment. Moreover, the use of the Coriolis micro allows the detection of emergent molecules around the Thau lagoon.

Characterization of cultivable airborne bacteria and their antimicrobial resistance pattern in French milking parlour.

The main goal of this preliminary study was to quantify airborne particles and characterize the dominant cultivable bacterial species as well as some Gram-positive species, and their antibiotic resistance pattern, from environmental samples taken inside and outside of a dairy milking parlour. Sampling was performed over 2 days, in different seasons. The small viable particulate matter < 10 µm (bioaerosols) and cultivable bacteria reached their highest concentrations in the milking parlour. The majority of airborne bacteria in the milking parlour belonged to the genera Staphylococcus (41.9%) and Bacillus (20.9%). A total of 32 different bacterial species of Staphylococcus, Aerococcus, Bacillus, Pseudomonas, Serratia and Acinetobacter were identified. Many of these bacteria may be opportunistic pathogens, causing disease in humans or animals. We found low levels of acquired resistance to the antibiotics commonly used in human or animal infections caused by these opportunistic bacteria. More specifically, resistance to tetracyclines (13.4%), penicillin G (13.4%) and macrolides (7.5%) was identified in Staphylococcus sp. as was a methicillin-resistant S. hominis and resistance to spiramycin (n = 1), lincomycin (n = 1) and streptomycin (n = 2) in Aerococcus sp. An assessment of the occupational risk run by dairy farmers for contracting infections after long- or short-term exposure to micro-organisms requires further studies on the concentration of opportunistic pathogenic bacteria in dairy farm environments.

Critical parameters in surface plasmon resonance biosensor development: The interaction between estrogen receptor and estrogen response element as model.

Estrogenic compounds are contaminants that may be active at low concentrations and are a major concern for environmental quality. They interact with organisms via Estrogen Receptors (ER). Some detection methods which have been developed use the ability of ER to interact with short consensus DNA sequences known as Estrogen Response Elements (ERE). Surface Plasmon Resonance (SPR) based techniques allow detection of interaction without labelled molecule use. Such optical transductors are widely used to convert the biological recognition signals into electric quantifiable signals. In this study, SPR is used to assess signal variation in the presence of estrogenic compounds. The combination of physical properties and biological recognition events (e.g. ER/ERE) permits the development of biosensors. These require several steps: activation of the surface, DNA sequence binding, ERE sequence evaluation, ER preparation, characterization of binding properties and regeneration of the surface. This article focuses on the mode of surface activation, protein-DNA binding conditions and the regeneration of ERE. After giving a summary of the literature concerning the usual conditions employed in these steps, an evaluation of some key parameters is given.

Exploring the antimicrobial properties of dark-operating ceramic-based nanocomposite materials for the disinfection of indoor air.

As people spend more and more time inside, the quality of indoor air becomes crucial matter. This study explores the germicidal potential of two dark-operating germicidal composite materials designed to be applied for the indoor air disinfection under flow conditions. The first material, MnO2/AlPO4/γ-Al2O3 beads, is a donor-acceptor interactive composite capable of creating hydroxyl radicals HO∙. The second one is a ZnO/γ-Al2O3 material with intercropped hexagons on its surface. To determine the antimicrobial efficiency of these materials in life-like conditions, a pilot device was constructed that allows the test of the materials in dynamic conditions and agar diffusion inhibitory tests were also conducted. The results of the tests showed that the MnO2/AlPO4/γ-Al2O3 material has a germicidal effect in static conditions whereas ZnO/γ-Al2O3 does not. In dynamic conditions, the oxidizing MnO2/AlPO4/γ-Al2O3 material is the most efficient when using low air speed whereas the ZnO/γ-Al2O3 one becomes more efficient than the other materials when increasing the air linear speed. This ZnO/γ-Al2O3 dark-operating germicidal material manifests the ability to proceed the mechanical destruction of bacterial cells. Actually, the antimicrobial efficiency of materials in dynamic conditions varies regarding the air speed through the materials and that static tests are not representative of the behavior of the material for air disinfection. Depending on the conditions, the best strategy to inactivate microorganisms changes and abrasive structures are a field that needs further exploration as they are in most of the conditions tested the best way to quickly decrease the number of microorganisms.

A Combination of Real-Time PCR and High-Resolution Melting Analysis to Detect and Identify CpGV Genotypes Involved in Type I Resistance.

Cydia pomonella granulovirus, in particular CpGV-M isolate, is used as a biological control against the codling moth (CM), Cydia pomonella. As a result of intensive control over the years, codling moth populations have developed resistance against this isolate. This resistance is now called type I resistance. Isolates, among them, CpGV-R5, have been found that are able to overcome type I resistance. Both CpGV-M and CpGV-R5 are used in orchards to control the codling moth. High resolution melting (HRM) has been adapted to differentiate between CpGV-M and CpGV-R5 isolates. Specific PCR primers have been designed for the CpGV p38 gene, encompassing the variable region responsible for the ability to overcome resistance. Because each amplicon has a specific melting point, it is possible to identify the CpGV-M and CpGV-R5 genotypes and to quantify their relative proportion. This method has been validated using mixtures of occlusion bodies of each isolate at various proportions. Then, the HRM has been used to estimate the proportion of each genotype in infected larvae or in occlusion bodies (OBs) extracted from dead larvae. This method allows a rapid detection of genotype replication and enables the assessment of either success or failure of the infection in field conditions.

Active periodic electrograms in remote monitoring of pacemaker recipients: the PREMS study.

AIMS: Remote monitoring (RM) is considered as a standard of care for pacemaker recipients. Remote monitoring systems provide calendar-based intracardiac electrogram recordings (IEGM) only with the current pacemaker settings (passive IEGM). PREMS (Pacemaker Remote Electrogram Monitoring Study), an observational, multicentre trial, prospectively evaluated the clinical value of an active IEGM (aIEGM), including three 10-s sections (passive IEGM, encouraged sensing, and encouraged pacing), compared to other RM data and to its passive IEGM section. Secondary objectives included the added value of the aIEGM to fully assess the sensing and pacing functions of each lead. METHODS AND RESULTS: Patients were enrolled within 3 months after pacemaker implantation and followed until the first transmitted aIEGM, which was analysed together with all other RM data. In total, 567 patients were enrolled (79 ± 9 years, 62% men, 19% single-chamber, and 81% dual-chamber pacemakers). Of 547 aIEGMs transmitted in 547 patients, 161 [29.4%; 95% confidence interval (95% CI) 25.6-33.3%] indicated at least one anomaly non-detectable with certainty-or at all-on other RM data, including atrial arrhythmia, extrasystoles, undersensing, oversensing, and loss of capture. In 21.7% of cases the detected events deserved a corrective action. The sensing and pacing function of each lead could be fully assessed in 77.3% of aIEGM (95% CI 72.6-82.0%) vs. 15.5% (95% CI 11.4-19.6%) when considering only the passive IEGM section (P < 0.001). CONCLUSION: An active IEGM improves the clinical value of remote pacemaker follow-up. Furthermore, compared to a passive IEGM, the aIEGM increases the capability to fully assess remotely the sensing and pacing functions.

Investigation of Removal Capacities of Biofilters for Airborne Viable Micro-Organisms.

New emerging issues appears regarding the possible aerosolization of micro-organisms from biofilters to the ambient air. Traditional bioaerosol sampling and cultural methods used in literature offer relative efficiencies. In this study, a new method revolving around a particle counter capable of detecting total and viable particles in real time was used. This counter (BioTrak 9510-BD) uses laser-induced fluorescence (LIF) technology to determine the biological nature of the particle. The concentration of viable particles was measured on two semi-industrial pilot scale biofilters in order to estimate the Removal Efficiency in viable particles (REvp) in stable conditions and to examine the influence of pollutant feeding and relative humidification of the gaseous effluent on the REvp. The REvp of biofilters reached near 80% and highlighted both the stability of that removal and the statistical equivalence between two identical biofilters. Pollutant deprivation periods of 12 h, 48 h and 30 days were shown to have no influence on the biofilters' removal capacity, demonstrating the robustness and adaptation capacities of the flora. In contrast, a 90-day famine period turned the biofilters into emitters of viable particles. Finally, the humidification of the effluent was shown to negatively influence the removal capacity for viable particles, as drying off the air was shown to increase the REvp from 60 to 85%.

Estrogen receptor preparation effects on the receptor-DNA interaction by surface plasmon resonance.

Up to now, several studies have investigated estrogen receptor (ER)-estrogen response element (ERE) interaction using biosensors such as surface plasmon resonance. These strategies have aimed to understand the molecular mechanism of such interaction as well as the effect of the ligand on this interaction. These approaches start to be used to determine the mechanisms of protein/DNA interaction, in particular in the context of drug discovery or environmental applications. However, some physical and biochemical parameters (incubation time, temperature, protease inhibitor cocktail, and bovine serum albumin (BSA)) are not completely described in the literature and could deeply modify the obtained results. This paper aims to focus not only on the preliminary steps of sample preparation such as protein thawing and incubation conditions (time and temperature) but also on the evaluation of protease inhibitor cocktail and BSA effect on the measurement of ER-ERE interactions.

Biological Characteristics of Experimental Genotype Mixtures of Cydia Pomonella Granulovirus (CpGV): Ability to Control Susceptible and Resistant Pest Populations.

The detection of resistance in codling moth (Cydia pomonella) populations against the Mexican isolate of its granulovirus (CpGV-M), raised questions on the sustainability of the use of this biological insecticide. In resistant host cells, CpGV-M is not able to complete its replication cycle because replication is blocked at an early step. Virus isolates able to overcome this resistance have been characterized-among them, the CpGV-R5 isolate. In mixed infections on resistant insects, both CpGV-M and CpGV-R5 viruses replicate, while CpGV-M alone does not induce mortality. Genetically heterogeneous virus populations, containing 50% of each CpGV-M and CpGV-R5 appear to control resistant host populations as well as CpGV-R5 alone at the same final concentration, even if the concentration of CpGV-R5 is only half in the former. The use of mixed genotype virus preparations instead of genotypically homogeneous populations may constitute a better approach than traditional methods for the development of baculovirus-based biological insecticides.

Potentialities of coupling biological processes (biotrickler/biofilter) for the degradation of a mixture of sulphur compounds.

This study deals with the potential of biological processes combining a biotrickler and a biofilter to treat a mixture of sulphur-reduced compounds including dimethyl sulphide (DMS), dimethyl disulphide (DMDS) and hydrogen sulphide (H2S). As a reference, duplicated biofilters were implemented, and operating conditions were similar for all bioprocesses. The first step of this work was to determine the efficiency removal level achieved for each compound of the mixture and in a second step, to assess the longitudinal distribution of biodegradation activities and evaluate the total bacteria, Hyphomicrobium sp. and Thiobacillus thioparus densities along the bed height. A complete removal of hydrogen sulphide is reached at the start of the experiment within the first stage (biotrickler) of the coupling. This study highlighted that the coupling of a biotrickling filter and a biofilter is an interesting way to improve both removal efficiency levels (15-20% more) and kinetics of recalcitrant sulphur compounds such as DMS and DMDS. The total cell densities remained similar (around 1 × 10(10) 16S recombinant DNA (rDNA) copies g dry packing material) for duplicated biofilters and the biofilter below the biotrickling filter. The relative abundances of Hyphomicrobium sp. and T. thioparus have been estimated to an average of 10 ± 7.0 and 0.23 ± 0.07%, respectively, for all biofilters. Further investigation should allow achieving complete removal of DMS by starting the organic sulphur compound degradation within the first stage and surveying microbial community structure colonizing this complex system.

Impact of biochemical design on estrogen receptor/estrogen response element interaction by surface plasmon resonance technology.

The estrogen receptor (ER) is a transcription factor that binds under 17-ß-estradiol (E2) stimulation as homodimer to a short DNA consensus sequence named estrogen response element (ERE). The ER/ERE interaction has been assessed by several research groups through different methodologies notably by surface plasmon resonance (SPR) techniques. The biochemical parameters and conditions (solvent, ER concentration, salt, time and temperature) used to prepare samples before analysis were very different from one study to another. But no studies have aimed to compare the effect of these modifications on ER/ERE interaction. Therefore the main objective of the present paper was to assess the influence of biochemical parameters onto the ER/ERE interaction with the final aim to improve the comprehension of this interaction. Our results highlighted that parameters like solvent, ER concentration, salt and surfactant concentration, temperature and time deeply modify ER/ERE interaction. Nevertheless, the dimer formation under E2 stimulation occurred with all tested conditions. Altogether, incubation parameters of ER with E2, deeply modify its binding level onto ERE. These data constitute an important key point to consider for the improvement of ER/ERE detection method depending upon the aim of the study (interaction measurement, environmental detection, development of new technologies or devices).

One-stage biotrickling filter for the removal of a mixture of volatile pollutants from air: performance and microbial community analysis.

The biodegradation of gas-phase mixtures of methanol, α-pinene and H2S was examined in a biotrickling filter (BTF), inoculated with a microbial consortium composed of an autotrophic H2S-degrading culture, and pure strains of Candida boidinii, Rhodococcus erythropolis, and Ophiostoma stenoceras. The inlet concentrations of methanol, α-pinene and H2S varied from 0.05 to 3.3 gm(-3), 0.05 to 2.7 gm(-3), and 0.01 to 1.4 gm(-3), respectively, at empty bed residence times (EBRT) of either 38 or 26s. The maximum elimination capacities (ECmax) of the BTF were 302, 175, and 191 gm(-3)h(-1), with 100%, 67%, and >99% removal of methanol, α-pinene and H2S, respectively. The presence of methanol showed an antagonistic removal pattern for α-pinene, but the opposite did not occur. For α-pinene, inlet loading rates (ILRs) >150 gα-pinenem(-3)h(-1) affected its own removal in the BTF. The presence of H2S did not show any declining effect on the removal of both methanol and α-pinene.

Immediate and long-term results of a modified simultaneous kissing stenting for percutaneous coronary intervention of coronary artery bifurcation lesions.

OBJECTIVES: We propose a modified simultaneous kissing stenting technique (MSKS) based on systematic implantation of a protective stent in the proximal main vessel (PMV) proximally to the bifurcation before simultaneous kissing stenting (SKS). BACKGROUND: SKS has been proposed in large-size coronary vessel bifurcation lesions (BLs) when the PMV can accommodate two stents. SKS implies, however, low-pressure simultaneous final balloon inflations to avoid retrograde PMV dissection or rupture and therefore may not ensure optimal final stent apposition. METHODS: From January 2005 to May 2008, a total of 97 patients with 100 BLs (true bifurcation in 92%) who underwent MSKS were enrolled in a prospective registry. Drug-eluting stents were used for distal main vessel and side branch. Drug-eluting or large-size bare-metal stents were used as proximal protective stents. RESULTS: Immediate procedural success rate was 100%. Global restenosis rate was 10% (5% in the main vessel and 8% in the side branch) at follow-up angiogram performed at 7 months in all patients (100%). No patient had early or late stent thrombosis. Two cases of non-fatal very late stent thrombosis occurred at 46 and 64 months. Over a mean 4.5-year follow-up period, target lesion revascularization rate was 11%, with only 3% driven by clinical ischemia. CONCLUSION: Protective stent systematic implantation in the PMV represents a newly modified SKS technique that allows safe finalization of the procedure by high-pressure kissing balloon final inflation, ensuring optimal stent apposition with high immediate procedural success and low rates of long-term events.

Silver/chitosan/cellulose fibers foam composites: from synthesis to antibacterial properties.

Chitosan, associated with cellulose fibers, can be used for elaborating sponge-like structures (membranes, foams) for the binding of silver ions. The composite material has very promising antibacterial properties versus Pseudomonas aeruginosa (Gram(-))≫Escherichia coli (Gram(-))>Staphylococcus hominis (Gram(+))≫Staphylococcus aureus (Gram(+)). The amount of silver required for bactericidal effect is quite low (below 0.1 mg per disk, this means less than 6 mg Ag g(-1)) in antibiogram-type test but also for the treatment of water suspensions (in dynamic mode with water recycling). The presence of cellulose fibers improves the efficiency of metal binding, due to chitosan dispersion and enhancement of the availability and accessibility of amine groups. Silver nanoparticles (about 100 nm) were observed by scanning electron microscopy. The photo-reduction (exposure to sun light or UV lamp) leaded to the partial aggregation of silver nanoparticles: metal ions that were released tended to aggregate at the surface of the material.

Investigation of the acclimatization period: example of the microbial aerobic degradation of volatile organic compounds (VOCs).

The aim of this study is to better evaluate the occurrence of an acclimatization-enrichment period, defined as a selection period of consortia having the capability to biodegrade pollutants. In order to perform this evaluation, two experimental strategies were carried out and the results were studied carefully. Two laboratory-scale reactors were inoculated with activated sludge from an urban treatment plant. During the experiment, these reactors were supplied with a gaseous effluent containing VOCs. For both reactors, the composition is different. Three parameters were monitored to characterize the microflora: bacterial activities, bacterial densities, and the genetic structure of Bacteria and Eukarya domains (Single Strand Conformation Polymorphism fingerprint). The obtained results showed that the resultant biodegradation functions were equivalent. The bacterial community structure differs even if six co-migrated peaks were observed. These data suggest that the microbial communities in both reactors were altered differently in response to the treatment but developed a similar capacity to remove VOCs at the issue of this period. Furthermore, it is suggested that the experimental strategies developed in this work lead to an enrichment in terms of functionality and microbial diversity almost equivalent.

The chick embryo: an animal model for detection of the effects of hormonal compounds.

Hormonal compounds are a class of pharmaceutical product that disrupt the endocrine system of animals and humans. Exposure to these molecules, even at low concentrations, can have severely damaging effects on the environment, to organisms, and to humans. The cumulative presence of these compounds is also characterized by synergistic effects which are difficult to estimate. They are an underestimated danger to the environment and to the human population. This paper presents an in-vivo model enabling to assessment of the real impact of exposure to hormonal compounds and the synergistic effect which can be involved. The anatomical effects of in-ovo exposure to two natural estrogen compounds (estrone and estriol, at 600 ng g(-1)) and a synthetic estrogen (ethynylestradiol, at 20 ng g(-1)) have been investigated. Estrone and estriol lead to morphological defects, mainly in the urogenital system of the developing chick embryo, whereas ethynylestradiol has fewer effects. Estriol caused persistence of Müllerian ducts in 50% of male embryos and hypertrophic oviducts in 71% of females. Estrone had the same effects but at the percentages were lower. Kidney dysfunction was also observed, but only with estrone, in both males and females. We also tested estrogenic compounds in two types of cell line which are estrogen sensitive (BG1 and MCF7) then completed and confirmed our previous in-vivo results. Seven pharmaceutical-like compounds--estrone (E1), estradiol (E2), estriol (E3), ethynylestradiol (EE(2)), carbamazepine (C), genistein (G), and bisphenol-A (BPA)--were tested alone or in mixtures. Different effects on the two cell lines were observed, indicating that endocrine compounds can act differently on this organism. Experiments also showed that these molecules have synergistic action and induce more severe effects when they are in mixtures.

Biofiltration of volatile organic compounds.

The removal of volatile organic compounds (VOCs) from contaminated airstreams has become a major air pollution concern. Improvement of the biofiltration process commonly used for the removal of odorous compounds has led to a better control of key parameters, enabling the application of biofiltration to be extended also to the removal of VOCs. Moreover, biofiltration, which is based on the ability of micro-organisms to degrade a large variety of compounds, proves to be economical and environmentally viable. In a biofilter, the waste gas is forced to rise through a layer of packed porous material. Thus, pollutants contained in the gaseous effluent are oxidised or converted into biomass by the action of microorganisms previously fixed on the packing material. The biofiltration process is then based on two principal phenomena: (1) transfer of contaminants from the air to the water phase or support medium, (2) bioconversion of pollutants to biomass, metabolic end-products, or carbon dioxide and water. The diversity of biofiltration mechanisms and their interaction with the microflora mean that the biofilter is defined as a complex and structured ecosystem. As a result, in addition to operating conditions, research into the microbial ecology of biofilters is required in order better to optimise the management of such biological treatment systems.