Fluorescence determination of the total amount of tetracyclines by a flavonol-based supramolecular sensor.

Tetracyclines (TCs) are a group of broad-spectrum antibiotics against multiplying microorganisms yet with several adverse effects on humans. Since all types of TCs have the similar chemical skeleton and mechanism of action, quantification of total amount of TCs in the environment was of particular importance. To date, dozens of fluorescent probes have been reported for TCs detection, but only very few of them enabled detection of total TCs. In this study, we report a novel supramolecular sensor constructed by human serum albumin as the recognition moiety and a flavonol fluorophore as the indicator. Under the 370 nm UV excitation, this sensor exhibits the rapid response (5 s), acceptable sensitivity (limit of detection âˆ¼ 0.58 µM), long dynamic detection range (0-20 µM), prominent specificity, and excellent anti-interference properties for analysis of total TCs. The mechanism was carefully validated using 1H NMR, fluorescence titration experiments, molecular docking, and mass spectrometry. We expect this work can inspire more sensor design for TCs quantification.

Synergy of iron-natural phenolic microparticles and hydrophobic ionic liquid for enrichment of tetracycline residues in honey prior to HPLC-UV detection.

Iron-natural phenolic microparticles were developed as absorbents for dispersive micro solid phase extraction (D-µSPE) synergistic with hydrophobic ionic liquid (IL) for dispersive liquid-liquid microextraction (DLLME) to enrich tetracycline residues, including tetracycline, doxycycline, oxytetracycline and chlortetracycline. In situ iron microparticles synthesized from betel nut natural reagent were employed as an adsorbent for D-µSPE. The hydrophobic IL [Hmim][PF6] was synergistically utilized as an extraction solvent to extract and accumulate adsorbents bound with tetracyclines before quantitation by HPLC-UV. The synergistic combination of DLLME with D-µSPE provided excellent extraction recovery compared with individual extraction. The developed method was successfully applied to enrich and determine tetracycline residues in honey samples, with recoveries ranging from 80.0 to 121.5% and providing high enrichment factors ranging from 61 to 197. This alternative method is simple and rapid, with high extraction efficiency and a high enrichment factor and is also environmentally friendly for the analysis of tetracyclines.

A fluorescence and SERS dual-mode sensing on tetracycline antibiotics based on Ag@NH2-MIL-101(Al) nanoprobe.

Antibiotic residues are becoming more and more concern due to the increasingly serious resistance from bacteria to organism. On-site and accurate evaluation on antibiotics is necessary and urgent to effectively solve such public issue. To provide point-of-care-test (POCT) ideas for antibiotic accurate evaluation, a fluorescence (FL)-surface-enhanced Raman scattering (SERS) dual-mode detection of tetracycline antibiotic (TCs) was realized for the first time. Based on the inner filter effect in Ag@NH2-MIL-101(Al) nanoprobe, the fluorescence quenching was induced and the SERS signal was swiftly turn on through π-π interaction and hydrogen bonding in the presence of TCs. This FL-SERS dual mode sensor displayed excellent detection limits (FL in âˆ¼10-3 ppm, SERS in âˆ¼10-5 ppm), and achieved a reliable detection of TCs in honey with a recovery rate of 84.45%-112.08%. This method combines the advantages of FL and SERS detection, meanwhile, two techniques verified against each other to achieve highly sensitive and specific FL-SERS dual-mode sensor for TCs. We believe that such antibody-or aptamer-independent FL and SERS complementary nanoprobe can be applied to fast, direct and multiple sensing in environment and food hazards.

Prioritized regional management for antibiotics and heavy metals in animal manure across China.

High levels of antibiotics and heavy metals in animal manure pose a potential threat to both the ecological environment and public health. A regional knowledge of their distribution and risk assessment across China remains unclear. A dataset containing 4082 records covering a total of forty-two antibiotics and eight heavy metals was established for animal manure across China. The results showed that the residual concentration of antibiotics was in the order of tetracyclines > aminoglycosides > fluoroquinolones > macrolides > sulfonamides > ß-lactams, and that of heavy metals is Zn > Cu > Cr > Pb > Ni > As > Cd > Hg. The mean concentration of antibiotics and heavy metals was higher in pig manure compared to chicken and cow manure (Kruskal-Wallis test). The lowest level of antibiotics was observed in Northwest China based on geographic distribution characteristics. It was related to the high ratio of cow and sheep farming that less antibiotics were administered to. The pollution status of heavy metals was more severe in East China. Furthermore, high correlations were observed between antibiotics (tetracyclines) and heavy metals (Cu, Zn, and As). Especially, tetracycline in North China and Cd in Northeast China exhibited a high risk in manure; thus, they were priority regions for antibiotics/heavy metals pollution control. This study identified risk assessment of typical antibiotics and heavy metals in animal manure and emphasized the necessity of regional management across China.

Enzymatic degradation of tetracycline by Trametes versicolor laccase in a fluidized bed reactor.

Laccase from Trametes Versicolor was successfully immobilized on gelatin beads by a crosslinking reaction with glutaraldehyde. Immobilized laccases showed better stability towards pH and temperature than free laccases. Moreover, the immobilized laccases retained a good relative activity of 85 % after 20 days of storage at 4 °C. The degradation of tetracycline (TC) was studied with immobilized enzymes in both batch and fluidized bed reactors (FBR). The average degradation rate (1.59 mg h-1 Uenzymes-1) estimated over 24 h in the FBR was almost 5 times higher than in the stirred tank reactor. Maximum degradation rate achieved was 72 ± 1 % with a circulation flow rate of 80 mL min-1 and addition of air at a flowrate of 15 mL min-1. Study of the stability of the active beads under reaction conditions, shows that 45 % of the TC was degraded after 5 cycles of 24 h each. The toxicity of the TC solution before and after treatment was also investigated with microtox assays.

Adsorption of tetracycline by polycationic straw: Density functional theory calculation for mechanism and machine learning prediction for tetracyclines' remediation.

The abuse of antibiotics causes serious environmental pollution, whose removal has become a hot topic. The adsorption of tetracycline (TC) on a prepared polycationic straw (MMS) was investigated. The kinetic, thermodynamic and adsorption isotherm models showed that adsorption of TC by MMS was a spontaneous, monolayer reaction with coexistence of physical and chemical process. Density functional theory indicated that the adsorption of TC resulted from electrostatic interaction and hydrogen bonds, which proved the mechanism of TC by macromolecular biomass for the first time. The expected and empirical values of TC adsorption showed a high fit degree, through predication of machine learning, indicating the feasibility and avoiding lots of experiments. Further, the adsorption ability of MMS to other TCs was predicted, founding that the highest removal efficiency was doxycycline, which provides a novel strategy for removal of other pollution and reduce of economic and time cost in practical application.

Synthesis of novel oxytetracycline-molecularly imprinted polymer using a semi-covalent chemical imprinting approach for magnetic dispersive solid phase extraction of tetracyclines in water and milk samples.

In the present study, a highly efficient analytical method based on preconcentration of tetracyclines (TCs) in water and milk samples using a magnetic molecularly imprinted polymer (Fe3O4/SiO2/MIP) synthesized by means of a novel semi-covalent synthesis for TCs and determination by HPLC-DAD was proposed. Fe3O4/SiO2/MIP showed specific superficial area of 216.0 m2/g, superior to Fe3O4/SiO2/NIP (non-imprinted material) (103.6 m2/g). Using the Fe3O4/SiO2/MIP, the magnetic dispersive solid phase extraction (MDSPE) for four TCs (chlortetracycline, doxycycline, oxytetracycline, and tetracycline) was based on the preconcentration of 40.0 mL of sample (pH 4.0) vortex-assisted with 10 mg of Fe3O4/SiO2/MIP during 60 s. The method presented a limit of detection (LOD) in the range 0.26-0.60 µg/L, and preconcentration factor in the range 52.3-87.4-fold for the TCs. The method was applied to determine TCs in samples of lake water and cow milk with recovery results ranging from 96.0 to 102.0 %.

Mechanism of the toxic effects of tetracycline on blood meal digestion in Haemaphysalis longicornis.

The extensive utilization of antibiotics in the field of animal husbandry gives rise to various concerns pertaining to the environment and human health. Here, we demonstrate that the administration of tetracycline impedes blood meal digestion in the tick Haemaphysalis longicornis. Tissue sectioning, 16S rRNA high-throughput sequencing, and transcriptome sequencing of the midgut were employed to elucidate the mechanism underlying tetracycline toxicity. The treatment group consisted of engorged female ticks that were subjected to tetracycline microinjections (75 µg per tick), whereas the control group received sterile water injections. On days 2 and 4 following the injections, the tick body weight changes were assessed and the midguts were dissected and processed. Change in tick body weight in tetracycline-treated group was less than in the control group. In tetracycline-treated ticks, midgut epithelial cells were loosely connected and blood meal digestion was impaired compared to the control group. There was no significant change in midgut bacterial diversity after tetracycline treatment. On day 2 following treatment, the relative abundance of Escherichia-Shigella was significantly decreased, whereas the relative abundance of Allorhizobium was significantly increased compared to the control group. On day 4 following treatment, the relative abundance of Escherichia-Shigella, Allorhizobium, Ochrobactrum, and Acidibacter decreased significantly, whereas the relative abundance of Paraburkholderia and Pelomonas increased significantly. Tetracycline treatment also affected midgut gene expression, producing a cumulative effect wherein the differentially expressed genes (DEGs) were mostly down-regulated. KEGG enrichment pathway analysis revealed that on day 2 the up-regulated DEGs were significantly enriched in 21 pathways, including apoptosis and phagosome. Comparatively, the down-regulated DEGs were significantly enriched in 26 pathways, including N-glycan biosynthesis, lysosome, and autophagy. In contrast, on day 4 the up-regulated DEGs were significantly enriched in 10 pathways including aminoacyl-tRNA biosynthesis, ribosome biogenesis, RNA transport, and DNA replication, whereas the down-regulated differential genes were significantly enriched in 11 pathways including lysosome, peroxisome, N-glycan biosynthesis, and fatty acid synthesis. This indicates that tetracycline injection inhibited blood meal digestion by affecting midgut digestive cells, gut flora diversity, and gene expression. These findings could contribute to tick control by inhibiting blood meal digestion.

Pharmacological Management of Cholera: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Cholera is a potentially lethal diarrheal disease produced by Vibrio cholerae serotypes O1 El Tor and O139. Known since antiquity, the condition causes epidemics in many areas, particularly in Asia, Africa, and South America. Left untreated, the mortality may reach 50%. The crucial therapeutic intervention is intravenous or oral rehydration and correction of acidosis, dyselectrolytemia, and renal impairment. Antibiotic use represents the main pharmacological intervention. STUDY QUESTION: What are the milestones of the antibiotics use recommended by experts for the pharmacological management of cholera in the past century? STUDY DESIGN: To determine the changes in the experts' approach to the management of cholera and particularly the use of antibiotics as presented in a widely used textbook in the United States. DATA SOURCES: The chapters describing the management of cholera in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020. RESULTS: Sulfonamides were recommended in 1947, followed by the introduction of tetracyclines, chloramphenicol, and furazolidone in 1955. The options were restricted in 2000 to doxycycline. In the past decade, patients infected with strains known to have a degree a resistance to tetracyclines were treated with azithromycin or ciprofloxacin. Antibiotic use decreases the volume of stool and the duration of diarrhea but has not been considered lifesaving. Drugs with antimotility, antiemetic, or antisecretory properties are not useful. CONCLUSIONS: The utility of antibiotic use in cholera has been endorsed by experts, but only as an adjunct to rapid and complete fluid and electrolyte replacement.

Photocatalytic degradation of tetracycline antibiotics by RGO-CdTe composite with enhanced apparent quantum efficiency.

RGO-CdTe composite was synthesized using a straightforward, easy-to-realize, one-pot solvothermal technique. The synthesized composite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller method (BET), Raman spectra, UV-Vis absorption, and photoluminescence measurement. The RGO-CdTe composite exhibited 83.6% photocatalytic degradation efficiency for the aqueous tetracycline (TC) antibiotic solution and the apparent quantum yield (AQY) for the same was as high as 22.29% which is 2.63 times higher than that of CdTe. The scavenger investigation demonstrated that although hole acts as the leading active species, despite that, superoxide and hydroxyl radicals have also played crucial roles. The initial pH-dependent photocatalytic performance was measured. The zeta potential of the composite at different pH values was evaluated to establish the photocatalytic performance of the RGO-CdTe towards TC degradation at different pH. The recycling experiment depicts that only a 10% degradation performance declines after 5 times recycle use of the RGO-CdTe photocatalyst. An efficient photocurrent generation in RGO-CdTe thin film device has also been observed. Our study establishes as-synthesized composite of RGO-CdTe as a highly potential, and stable photocatalyst for the degradation of antibiotics from the polluted aqueous environment with a very good photoinduced charge generation efficiency in its solid phase.

Transcriptomic and metabolomic analyses reveal the essential nature of Rab1B in Toxoplasma gondii.

BACKGROUND: The protozoan parasite Toxoplasma gondii encodes a dozen Rab proteins, which are parts of the small GTPase superfamily and regulate intracellular membrane trafficking. Our previous study showed that depletion of Rab1B caused severe defects regarding parasite growth and morphological structure, yet early defects of endocytic trafficking and vesicle sorting to the rhoptry in T. gondii are not expected to have a strong effect. To understand this discrepancy, we performed an integrated analysis at the level of transcriptomics and metabolomics. METHODS: In the study, tetracycline-inducible TATi/Ty-Rab1B parasite line treated with ATc at three different time points (0, 18 and 24 h) was used. We first observed the morphological changes caused by Rab1B depletion via transmission electron technology. Then, high-throughput transcriptome along with non-targeted metabolomics were performed to analyze the RNA expression and metabolite changes in the Rab1B-depleted parasite. The essential nature of Rab1B in the parasite was revealed by the integrated omics approach. RESULTS: Transmission electron micrographs showed a strong disorganization of endo-membranes in the Rab1B-depleted parasites. Our deep analysis of transcriptome and metabolome identified 2181 and 2374 differentially expressed genes (DEGs) and 30 and 83 differentially expressed metabolites (DEMs) at 18 and 24 h of induction in the tetracycline-inducible parasite line, respectively. These DEGs included key genes associated with crucial organelles that contain the rhoptry, microneme, endoplasmic reticulum and Golgi apparatus. The analysis of qRT-PCR verified some of the key DEGs identified by RNA-Seq, supporting that the key vesicular regulator Rab1B was involved in biogenesis of multiple parasite organelles. Functional enrichment analyses revealed pathways related to central carbon metabolisms and lipid metabolisms, such as the TCA cycle, glycerophospholipid metabolism and fatty acid biosynthesis and elongation. Further correlation analysis of the major DEMs and DEGs supported the role of Rab1B in biogenesis of fatty acids (e.g. myrisoleic acid and oleic acid) (R > 0.95 and P < 0.05), which was consistent with the scavenging role in biotin via the endocytic process. CONCLUSIONS: Rab1B played an important role in parasite growth and morphology, which was supported by the replication assay and transmission electron microscopy observation. Our multi-omics analyses provided detailed insights into the overall impact on the parasite upon depletion of the protein. These analyses reinforced the role of Rab1B in the endocytic process, which has an impact on fatty acid biogenesis and the TCA cycle. Taken together, these findings contribute to our understanding of a key vesicular regulator, Rab1B, on parasite metabolism and morphological formation in T. gondii.

One Pot Synthesis of Nanofiber-Coated Magnetic Composites as Magnetic Dispersive Solid-Phase Extraction Adsorbents for Rapid Determination of Tetracyclines in Aquatic Food Products.

A magnetic adsorbent based on a C-nanofiber (Fe3O4@C-NFs) nanocomposite was synthesized using a simple one-pot co-precipitation method. The characterized results showed that the obtained C-nanofiber-coated magnetic nanoparticles had many attractive features such as a large specific surface area and a highly interwoven and branched mesoporous structure, as well as distinguished magnetism. The nanocomposite was then used as an adsorbent in the magnetic solid phase extraction (MSPE) of four typical tetracyclines (oxytetracycline, tetracycline, chlortetracycline, and doxycycline) in aquatic products. The TCs in the extract were determined using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Experimental variables of MSPE, including the sorbent amount, pH condition, adsorption and desorption time, and desorption solvent, were investigated and optimized systematically. The method validation indicated that the developed method showed good linearity (R2 > 0.995) in the range of 1.0-200 ng/mL. The average recoveries at the spiked levels ranged from 90.7% to 102.7% with intra-day and inter-day relative standard deviations (RSDs, n = 6) ranging from 3.72% to 8.17% and 4.20% to 9.69%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for the four kinds of TCs were 0.7 µg/kg and 2.0 µg/kg, respectively. Finally, MSPE based on C-nanofiber-coated magnetic nanoparticles was successfully applied to TC analysis in real aquatic products (grass carp, large yellow croaker, snakehead, mandarin fish, Penaeus vannamei, swimming crab, etc.). Compared with traditional extraction methods, the proposed method for TC analysis in aquatic products is more sensitive, effective, recyclable, and environmentally friendly.

Case Report: Omadacycline in the treatment of macrolide-unresponsive Mycoplasma pneumoniae pneumonia in an adolescent patient.

Omadacycline is a novel tetracycline antibiotic that exhibits good in vitro antibacterial activity against atypical pathogens such as Mycoplasma pneumoniae. It is approved for the treatment of adults with community-acquired bacterial pneumonia. However, the safety and efficacy of omadacycline in pediatric patients under 18 years of age have not yet been established. In the present paper, we report a case of pediatric community-acquired pneumonia in which initial empirical anti-infective therapy had failed. The patient received empirical anti-infective therapy with azithromycin and other antimicrobial agents upon admission but showed a poor clinical response and developed secondary tinnitus and liver dysfunction. After the confirmation of M. pneumoniae infection through metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid, an antibiotic switch to omadacycline was made. Thereafter, the patient's condition improved, and no adverse reactions were observed. These findings demonstrate that mNGS enables the identification of infection-causing pathogens in patients with unresponsive pneumonia. Omadacycline can be considered as an alternative option for anti-infective therapy in pediatric M. pneumoniae pneumonia, especially when the presence of bacterial resistance, adverse drug reactions, or organ failure are taken into consideration.

Ensuring Dermatologists Practice Enhanced Antibiotic Stewardship With Sarecycline Mnemonic.

It must be ensured that dermatologists practice enhanced antibiotic stewardship to combat antimicrobial resistance and negative consequences of microbiome dysbiosis. In order to help achieve this, we have developed a mnemonic ENLIGHTEN to help healthcare providers and patients understand sarecycline’s features.J Drugs Dermatol. 2023;22(10):1061 doi:10.36849/JDD.7437R1.

Tetracyclines uptake from irrigation water by vegetables: Accumulation and antimicrobial resistance risks.

Wastewater irrigation may introduce antibiotic residues in the soil-plant systems. This study aimed to investigate the uptake of tetracyclines by spinach and collard greens and assess associated ecological and human health risks. Synthetic wastewater spiked with 1 ppm and 10 ppm of oxytetracycline, doxycycline, and tetracycline was used to grow vegetables in a greenhouse pot experiment. The uptake and accumulation of the tetracyclines were low and residual concentrations in the soil were negligible. All the tetracyclines were detected at concentrations ranging from 1.68 to 51.41 µg/g (spinach) and 1.94-30.95 µg/g (collard greens). The accumulation rate was in a dose-response scenario with a bioconcentration factor of 6.34 mL/kg (spinach) and 2.64 mL/kg (collard greens). Oxytetracycline had the highest accumulation in leaves, followed by doxycycline and tetracycline, and the residual concentrations followed the same order. The highest residual concentration was in soils receiving 10 ppm oxytetracycline. Residual concentrations in the soil were lower than accumulated levels and exerted negligible ecological risks. Tetracyclines accumulation in spinach significantly differed between the vegetables demonstrating a subspecies difference in uptake and accumulation. Ecological risk quotient (RQ) and human health risk quotient (HQ) were below thresholds that would exert toxicity and resistance selection impacts. Although RQs and HQs are low (<0.1), this study shows that the vegetables accumulate tetracyclines from irrigation water, posing plausible human health risks to allergic individuals. Similarly, the ecological risks cannot be ignored because the synergistic and antagonistic effects of sublethal concentrations can perturb ecosystem processes.

Aspartate metabolic flux promotes nitric oxide to eliminate both antibiotic-sensitive and -resistant Edwardsiella tarda in zebrafish.

Introduction: Metabolic reprogramming potentiates host protection against antibiotic-sensitive or -resistant bacteria. However, it remains unclear whether a single reprogramming metabolite is effective enough to combat both antibiotic-sensitive and -resistant bacteria. This knowledge is key for implementing an antibiotic-free approach. Methods: The reprogramming metabolome approach was adopted to characterize the metabolic state of zebrafish infected with tetracycline-sensitive and -resistant Edwardsiella tarda and to identify overlapping depressed metabolite in dying zebrafish as a reprogramming metabolite. Results: Aspartate was identify overlapping depressed metabolite in dying zebrafish as a reprogramming metabolite. Exogenous aspartate protects zebrafish against infection caused by tetracycline-sensitive and -resistant E. tarda. Mechanistically, exogenous aspartate promotes nitric oxide (NO) biosynthesis. NO is a well-documented factor of promoting innate immunity against bacteria, but whether it can play a role in eliminating both tetracycline-sensitive and -resistant E. tarda is unknown. Thus, in this study, aspartate was replaced with sodium nitroprusside to provide NO, which led to similar aspartate-induced protection against tetracycline-sensitive and -resistant E. tarda. Discussion: These findings support the conclusion that aspartate plays an important protective role through NO against both types of E. tarda. Importantly, we found that tetracycline-sensitive and -resistant E. tarda are sensitive to NO. Therefore, aspartate is an effective reprogramming metabolite that allows implementation of an antibiotic-free approach against bacterial pathogens.

An integrated multimedia fate modeling framework for identifying mitigation strategy of antibiotic ecological risks: A case study in a peri-urban river.

Antibiotics have been heavily used over the past decades, resulting in their frequent detections in rivers and increasing ecological risks. Recognizing characteristics of antibiotic ecological risks (AERs) and making effective strategies to mitigate the AERs are essential to ensure the safety of aquatic ecosystem and public health. In this study, an integrated technological framework has been proposed toward identifying management options for reducing AERs by jointly utilizing multimedia fugacity modelling and ecotoxicological risk assessment, and applied to characterize the AERs in a peri-urban river in Beijing. Specifically, a level III fugacity model has been successfully established to simulate the fate of antibiotics in the environment, and the manageable parameters have been screened out via sensitivity analysis of the model. Then the validated fugacity model has been used for scenario modellings to optimize mitigation strategies of AERs. Results show most of the antibiotics considered are frequently detected in the river, and pose medium or high risks to aquatic organisms. Relatively, the macrolides and fluoroquinolones present higher ecotoxicological risks than sulfonamides and tetracyclines. Furthermore, the mixture risk quotient and predictive equation of concentration addition suggest joint and synergistic/antagonistic effects of AERs for multiple or binary antibiotics in the environment. Largely, the concentrations of antibiotics in the river are determined by the source emissions into water and soil. Scenario modellings show the improvement of antibiotic removal rates would be considered preferentially to mitigate the AERs. Also, controlling human consumption is conducive to reducing the risks posed by tetracyclines, macrolides and trimethoprim, while controlling animal consumption would benefit the reduction for sulfonamides. Overall, the joint strategy presents the greatest reduction of AERs by reducing antibiotic consumption and together improving sewage treatment rate and antibiotic removal rate. The study provides us a useful guideline to make ecological risk-based mitigation strategy for reducing AERs in environment.

SF-1 Induces Nuclear PIP2.

Metazoan cell nuclei contain non-membrane pools of the phosphoinositide lipid PI(4,5)P2 (PIP2), but how this hydrophobic lipid exists within the aqueous nucleoplasm remains unclear. Steroidogenic Factor-1 (NR5A1, SF-1) is a nuclear receptor that binds PIP2 in vitro, and a co-crystal structure of the complex suggests the acyl chains of PIP2 are hidden in the hydrophobic core of the SF-1 protein while the PIP2 headgroup is solvent-exposed. This binding mode explains how SF-1 can solubilize nuclear PIP2; however, cellular evidence that SF-1 expression associates with nuclear PIP2 has been lacking. Here, we examined if tetracycline induction of SF-1 expression would associate with nuclear accumulation of PIP2, using antibodies directed against the PIP2 headgroup. Indeed, tetracycline induction of wild-type SF-1 induced a signal in the nucleus of HEK cells that cross-reacts with PIP2 antibodies, but did not cross-react with antibodies against the lower abundance phosphoinositide PI(3,4,5)P3 (PIP3). The nuclear PIP2 signal co-localized with FLAG-tagged SF-1 in the nuclear compartment. To determine if the nuclear PIP2 signal was dependent on the ability of SF-1 to bind PIP2, we examined a "pocket mutant" of SF-1 (A270W, L345F) shown to be deficient in phospholipid binding by mass spectrometry. Tetracycline induction of this pocket mutant SF-1 in HEK cells failed to induce a detectable PIP2 antibody cross-reactive signal, despite similar Tet-induced expression levels of the wild-type and pocket mutant SF-1 proteins in these cells. Together, these data are the first to suggest that expression of SF-1 induces a PIP2 antibody cross-reactive signal in the nucleus, consistent with X-ray crystallographic and biochemical evidence suggesting SF-1 binds PIP2 in human cells.

Photo-Fenton degradation of tetracycline antibiotic over MIL-101(Cr)/FeOOH nanocomposite as stable and efficient visible light responsive photocatalyst.

Designing an inexpensive, easily synthesized, stable and efficient photocatalyst is a major challenge in photocatalysis area, especially when photo-reaction is performed in aquatic medium to degrade organic pollutants. To this aim, nano-sized MIL-101(Cr) (MIL = Materials Institute Lavoisier), as chemically tolerant metal-organic framework (MOF), was simply prepared via HF-free hydrothermal synthesis procedure. In order to decorate amorphous FeOOH quantum dots (QDs) on the surface of this MOF, various amounts of FeOOH QDs (i.e., 5, 10, 15 and 20 wt%) were synthesized in the presence of MIL-101(Cr) to prepare MIL-101(Cr)/FeOOH(x%) nanocomposites. Decoration of such iron oxide quantum dots on the surface of MIL-101(Cr) and investigation of its activity in photo-Fenton degradation of tetracycline (TC) antibiotic is reported here for the first time. Among the synthesized nanocomposites, MIL-101(Cr)/FeOOH(15%) demonstrated superior photo-Fenton activity in degradation of TC (80%) at short reaction time under optimum reaction condition using the energy-efficient white LED lamps as visible light source. It was observed that the synergy between any component of this photo-Fenton system such as nanocomposite, hydrogen peroxide and visible light is the main reason for enhancement of TC removal over time. Also, neither MIL-101(Cr) nor FeOOH QDs exhibited poor degradation efficiency, which implies the positive role of the coupling of these materials. Furthermore, the stability and recoverability of MIL-101(Cr)/FeOOH(15%) nanocomposite was investigated in four photo-Fenton cycles, which no significant decrease in TC degradation performance was observed.

Sequencing-based analysis of the microbiomes of Spanish food processing facilities reveals environment-specific variation in the dominant taxa and antibiotic resistance genes.

In the last years, advances in high throughput sequencing technologies have opened the possibility to broaden environmental monitoring activities in facilities processing food, offering expanded opportunities for characterizing in an untargeted manner the microbiome and resistome of foods and food processing environments (FPE) with huge potential benefits in food safety management systems. Here the microbiome and resistome of FPE from slaughterhouses (n = 3), dairy (n = 12) and meat (n = 10) processing plants were assessed through whole metagenome sequencing of 2 composite samples for each facility, comprising 10 FPE swabs taken from food contact surfaces and 10 FPE samples from non-food contact surfaces, respectively. FPE from slaughterhouses had more diverse microbiomes and resistomes, while FPE from dairy processing plants showed the highest ß-dispersion, consistent with a more heterogeneous microbiome and resistome composition. The predominant bacterial genera depended on the industry type, with Pseudomonas and Psychrobacter being highly dominant in surfaces from slaughterhouses and meat industries, while different lactic acid bacteria predominated in dairy industries. The most abundant antimicrobial resistance genes (ARG) found were associated with resistance to aminoglycosides, tetracyclines and quaternary ammonium compounds (QAC). ARGs relating to resistance to aminoglycosides and tetracyclines were significantly more prevalent in slaughterhouses than in food processing plants, while QAC resistance genes were particularly abundant in some food contact surfaces from dairy and meat processing plants, suggesting that daily sanitation under suboptimal conditions may be selecting for persistent microbiota tolerant to these biocides in some facilities. The taxonomic mapping of ARG pointed to specific bacterial genera, such as Escherichia, Bacillus, or Staphylococcus, as carriers of the most relevant resistance determinants. About 63% of all ARG reads were assigned to contigs classified as plasmid-associated, indicating that the resistome of FPE may be strongly shaped through the spread of mobile genetic elements. Overall, the relevance of FPE as reservoirs of ARG was confirmed and it was demonstrated that next generation sequencing technologies allowing a deep characterisation of sources and routes of spread of microorganisms and antimicrobial resistance determinants in food industry settings hold promise to be integrated in monitoring and food safety management programmes.