Magnetization and ZIF-67 modification of Aspergillus flavus biomass for tetracycline removal from aqueous solutions: A stable and efficient composite.

In the present work, the biomass of Aspergillus flavus (AF) was modified using magnetic nanoparticles MnFe2O4 and metal-organic framework of ZIF-67, and its ability to remove tetracycline antibiotic (TCH) was investigated. With the help of physicochemical tests, AF biomass modification with ZIF-67 and MnFe2O4 magnetic nanoparticles was confirmed. Based on the BET value, AF-MnFe2O4-ZIF-67 (139.83 m2/g) has a higher surface value than AF (0.786 m2/g) and AF/MnFe2O4 (17.504 m2/g). Also, the magnetic saturation value revealed that the modified biomass can be isolated from the treated solution using a simple magnetic field. Maximum TCH elimination (99.04%) using AF-MnFe2O4-ZIF-67 was obtained at pH 7, adsorber mass of 1 g/L, adsorption time of 40 min, and TCH content of 10 mg/L. The thermodynamic study indicated that the TCH abatement using the desired composite is spontaneous and exothermic. The experimental results showed that the adsorption process is compatible with the pseudo-second-order kinetic and Freundlich model. The maximum adsorption capacity for AF, AF-MnFe2O4, and AF-MnFe2O4-ZIF-67 was quantified to be 9.75 mg/g, 25.59 mg/g, and 43.87 mg/g, respectively. The reusability of the desired adsorbers was examined in up to 8 steps. The outcomes showed that the adsorbers can be used several times in TCH elimination. The provided composite can remove TCH from hospital wastewater, so it can be suggested for use in water and wastewater treatment works.

Rhabdomyolysis Suspected to be Caused by Eravacycline Therapy: A Case Report.

Eravacycline is approved by the U.S. Food and Drug Administration (FDA) for the treatment of complicated intra-abdominal infections. It is a novel, fully synthetic fluorocycline antibiotic belonging to the tetracycline class with a broad-spectrum of activity and an appealing side effect profile. This report describes a 74-year-old female who presented to the hospital with non-ST-elevation myocardial infarction (NSTEMI) requiring coronary artery bypass graft surgery. After surgery, she developed a sternal wound infection that grew multidrug resistant organisms, leading to a much longer than anticipated hospital stay. Eravacycline was eventually added to the antimicrobial regimen for the persistent infection. Shortly after therapy with eravacycline began, the patient started experiencing muscle pain and the creatine phosphokinase (CPK) level was noted to be elevated. Other causes, such as concomitant administration of an HMG-CoA reductase inhibitor, were explored in this case but not thought to be the cause of rhabdomyolysis. The patient's CPK dropped considerably upon discontinuation of the novel antibiotic, and symptoms resolved. The adverse drug event was reported to the drug manufacturer; however, there are no reports up until this time that address a possible relationship between eravacycline administration and the development of rhabdomyolysis.

Highly efficient ultrasound-driven Cu-MOF/ZnWO4 heterostructure: An efficient visible-light photocatalyst with robust stability for complete degradation of tetracycline.

Metal-organic frameworks (MOFs) are a significant class of porous, crystalline materials composed of metal ions (clusters) and organic ligands. The potential use of copper MOF (Cu-BTC) for the sonophotocatalytic degradation of Tetracycline (TC) antibiotic was investigated in this study. To enhance its catalytic efficiency, S-scheme heterojunction was created by combining Cu-BTC with Zinc tungstate (ZnWO4), employing an ultrasound-assisted hydrothermal method. The results demonstrated that the Cu-BTC/ZnWO4 heterojunction exhibited complete removal of TC within 60 min under simultaneous irradiation of visible light and ultrasound. Interestingly, the sonophotocatalytic degradation of TC using the Cu-BTC/ZnWO4 heterojunction showed superior efficiency (with a synergy index of ∼0.70) compared to individual sonocatalytic and photocatalytic degradation processes using the same heterojunction. This enhancement in sonophotocatalytic activity can be attributed to the formation of an S-scheme heterojunction between Cu-BTC and ZnWO4. Within this heterojunction, electrons migrated from Cu-BTC to ZnWO4, facilitated by the interface between the two materials. Under visible light irradiation, the built-in electric field, band edge bending, and coulomb interaction synergistically inhibited the recombination of electron-hole pairs. Consequently, the accumulated electrons in Cu-BTC and holes in ZnWO4 actively participated in the redox reactions, generating free radicals that effectively attacked the TC molecules. This study offers valuable perspectives on the application of a newly developed S-scheme heterojunction photocatalyst, demonstrating its effectiveness in efficiently eliminating diverse recalcitrant pollutants via sonophotocatalytic degradation.

Effect of pH on Adsorption of Tetracycline Antibiotics on Graphene Oxide.

Graphene oxide (GO) has good dispersibility and adsorption capacity for antibiotics adsorption, a complex process influenced by many factors. In this work, the adsorption mechanism of GO on tetracycline antibiotics at different pH was studied to address its attenuated effects on the microbial growth. The results showed that the adsorption process of GO on three antibiotics, namely, tetracycline (TC), oxytetracycline (OTC), and chlortetracycline (CTC), followed the pseudo-second-order kinetic model. The maximum adsorption capacities were observed at pH5 which were 133.0 mg/g for TC, 125.4 mg/g for OTC, and 167.0 mg/g for CTC. Furthermore, the reaction was uniform adsorption with a single layer on the surface of GO, and heating was conducive to the reaction. In the microbial growth experiment, the growth of E. coli and B. subtilis senses was optimal at pH5, which was consistent with the adsorption experiment. This study analyzed the effect of pH on the adsorption of antibiotics by GO and provided a theoretical basis for the further application of GO in various aquatic environments.

Photocatalytic degradation of tetracycline antibiotic and organic dyes using biogenic synthesized CuO/Fe2O3 nanocomposite: pathways and mechanism insights.

Tetracycline (TC) is a frequently administered antibiotic in many countries, due to its low price and excellent potency. However, certain antibiotics can be hazardous to living creatures due to their accumulation by complexation with metal ions which can contribute to teratogenicity and carcinogenicity. In this investigation, copper oxide-ferric oxide nanocomposite (CuO/Fe2O3 nanocomposite) was synthesized employing Psidium guajava (P. guajava) leaf extract as a reductant as well as a capping agent in an environment friendly and economical green synthesis method. The as-synthesized CuO/Fe2O3 nanocomposite was comprehensively characterized using various sophisticated techniques and its efficiency as a photocatalyst for degradation of tetracycline (TC) antibiotic and toxic dyes, i.e., rhodamine B (RhB) and methylene blue (MB) were investigated. The CuO/Fe2O3 nanocomposite exhibited exceptional efficiency for degradation of TC antibiotic (88% removal in 80 min), RhB (96% removal in 40 min), and MB (93% elimination in 40 min) with apparent rate constant of 0.048, 0.068, and 0.032 min-1, respectively. In the degradation experiments, photocatalytic activity of CuO/Fe2O3 nanocomposite was studied by varying different factors such as time of contact, catalyst dose, and solution pH. The role of reactive species in antibiotics and dye degradation was validated by radical scavenging studies which indicated that.OH radical played a critical role in photocatalytic decomposition. Furthermore, liquid chromatography-mass spectrometry (LC-MS) investigations were employed to anticipate a plausible mechanism for TC degradation.

Tunable band structure of synthesized carbon dots modified graphitic carbon nitride/bismuth oxychlorobromide heterojunction for photocatalytic degradation of tetracycline in water.

In this study, graphitic carbon nitride (CN) decorated with carbon quantum dot (CQD) and bismuth oxychlorobromide (BiOClxBr1-x) was fabricated by calcination and hydrothermal methods. The morphology characterization of the synthesized photocatalyst revealed that CQD and BiOClxBr1-x solid solution were deposited on the CN surface. CQD served as the electron reservoir, which could reduce the recombination of electron-hole pairs, thus improving the overall photocatalytic performance. The synergistic effect of 1 wt% CQDs and BiOCl0.75Br0.25 markedly improved the interfacial charge transfer efficiency and light-harvesting capacity of the composite. The degradation rate of tetracycline (TC) over CN/CQD/BiOCl0.75Br0.25 was 83.4 % after 30 min and favorable stability with near-initial capacity under visible light irradiation. Meanwhile, the reaction mechanism of the photocatalytic performance was demonstrated by the analysis of the surface adsorption sites, efficient utilization of visible light, and charge carrier transfer. The degradation by-products and potential degradation pathways were also analyzed using liquid chromatography-mass spectrometry. Finally, the toxicity estimation software tool (T.E.S.T) analysis indicated that the toxicity of most intermediates was lower than TC. This work provideed a strategy for fabricating visible light (VL) photocatalyst with excellent photocatalytic activity, furnishing a new insight for interface charge transfer.

Optimization of tetracycline removal from water by iron-coated pine-bark biochar.

We synthesized iron-coated pine-bark biochar (Fe-PBB) and determined the optimal conditions for removing the antibiotic tetracycline from water. The Fe-PBB was synthesized by depositing iron oxide on pyrolyzed pine-bark waste via a facile co-precipitation method. Characterization (SEM, EDX, and TGA) showed successful deposition of a mass of approximately 27% (w/w) iron on the PBB to synthesize Fe-PBB. Fe-PBB exhibited five times higher adsorption capacity (~ 10 mg/g) for tetracycline compared with PBB. The effects of initial tetracycline concentration, pH, temperature, and Fe-PBB dose on the adsorption removal of tetracycline from water were systematically investigated and optimized using a statistical experimental design and response surface methodology. The empirical relationship between the experimental factors and tetracycline removal was modeled, statistically validated through the analysis of variance, and used to predict the optimal conditions for adsorption removal of tetracycline. We found that ≥ 95% of the tetracycline can be removed at a tetracycline concentration of 1 mg/L, pH of 7, temperature of 50 °C, and a Fe-PBB dose of 2 g/L. The adsorption isotherm modeling study suggests that the adsorption of tetracycline can be attributed to the pore filling phenomenon and multilayer adsorption on the Fe-PBB. A thermodynamics study showed that the adsorption occurs spontaneously with an endothermic reaction.

Antibiotic Resistance Risk with Oral Tetracycline Treatment of Acne Vulgaris.

Almost 1 billion people worldwide have acne, and oral tetracyclines, including doxycycline and minocycline, are effective and frequently prescribed treatments for acne. However, there is growing concern for the development of antibiotic resistance with such widespread utilization by dermatologists. Additionally, tetracyclines are known to have various potential side effects, including gut dysbiosis, gastrointestinal upset, photosensitivity, dizziness, and vertigo. However, in 2018 a novel narrow-spectrum tetracycline, sarecycline, was Food and Drug Administration-approved to treat moderate-to-severe acne vulgaris in patients 9-years-old and above. Sarecycline was designed to target Cutibacterium acnes, the pathogenic bacterium in acne vulgaris, which may reduce the risk of resistance. This paper examines the growing concerns of antibiotic resistance due to oral tetracycline usage in the treatment of acne vulgaris, with a focus on the promising third-generation, narrow-spectrum tetracycline, sarecycline.

Dual-functional CDs@ZIF-8/chitosan luminescent film sensors for simultaneous detection and adsorption of tetracycline.

Tetracycline (TC) residues have been noted as an important class of emerging contaminants in the environment, thus fast, straightforward, highly sensitive detection method is becoming an issue that must be addressed. Herein, a novel CDs@ZIF-8 sensing material was fabricated by encapsulating luminescent carbon dots (CDs) into the metal-organic framework (ZIF-8) to achieve highly luminescent porous composites. Furthermore, to avoid the secondary contamination caused by powders, a shapable CDs@ZIF-8/CS film sensor as a portable disposable test strip with dual-function of TC detection and adsorption was designed by crosslinking CDs@ZIF-8 with chitosan (CS). The as-prepared CDs@ZIF-8/CS hybrid film exhibited the high sensitivity and selectivity for TC fluorescence detection and rapid decontaminate capability, as well as high optical transmittance and robust mechanical property, which were essential for the practical sensing application. This paper-based dual-functional luminescent sensor exhibits promising practicability for TC detection and contaminant removal in pharmaceutical analysis, food safety and water treatment.

Application of biogenic iron precipitation by strain H117 for tetracycline removal: mechanism of adsorption and activation.

To date, biogenic metals have opened up a window for new applications in adsorption of contaminants. But there is still little attention to be paid in the removal of tetracycline (TC) by biogenic iron precipitation (BIP). In this paper, the BIP, from iron-based mixotrophic denitrification batch reactor, was estimated for its adsorption property of TC under various parameters to simulate the behavior in aquatic environment. The maximum adsorption capacity for TC was 195.336 mg g-1. Analyses of spectrum verified the existence of Fe3O4 and FeOOH in BIP, which was the main reason for the removal of TC. The adsorption kinetic and isotherm of TC were well fitted to Elovich and Langmuir isotherm models, respectively, indicating that the adsorption process was mainly controlled by chemical adsorption. Furthermore, we proposed a potential mechanism of adsorption: a combination of cation-π, hydrogen bonding (H-bonding), and electrostatic interaction. Additionally, the activation experiment showed that BIP could enhance the degradation of TC (more than 98.00% removal within 1.0 h) by advanced oxidation process (AOP), due to the existence of FeOOH and Fe3O4. Considering its effectiveness in both adsorption and activation performance, BIP is highlighted as an economical and eco-friendly material for TC removal and offers a promising method to resolve sludge disposal in biological treatment of iron-rich groundwater.

Tetracycline antibiotics as precursors of dichloroacetamide and other disinfection byproducts during chlorination and chloramination.

Pollution of natural water and even source water with pharmaceuticals is problematic worldwide and raises concern about the possibility of disinfection byproduct (DBP) formation during subsequent water treatment. In this study, the formation of DBPs, especially dichloroacetamide (DCAcAm), was investigated during chlorination and chloramination of tetracyclines, which are a class of broad-spectrum antibiotics. DBPs including DCAcAm were formed during chlorination and chloramination of tetracycline (TC). Although the concentrations and theoretical cytotoxicity of the DBPs formed from TC were affected by the contact time, disinfectant dose, and pH, DCAcAm was the main contributor determining the yields and cytotoxicity of the measured DBPs. The DCAcAm yields from four tetracycline antibiotics ranged from 0.43% to 54.26% for chlorination. For chloramination, the DCAcAm yields reached 44.57%, and the nitrogen in DCAcAm mainly came from tetracycline antibiotics rather than chloramines. ClO2 pre-oxidation and UV photolysis decreased DCAcAm formation during chlorination and chloramination of TC. The high yields observed in this study suggest that tetracycline antibiotics are possible precursors of DCAcAm.

[Effect of Tetracycline Antibiotic on Abundance and Transcriptional Expression Level of Tetracycline Resistance Genes in Activated Sludge].

Tetracycline resistant bacteria (TRB) screened from activated sludge were used to study the effect of tetracycline (TC) antibiotic on the transcriptional expression of tetracycline resistance genes (TC-ARGs). The gene abundances of seven TC-ARGs including tetA, tetC, tetG, tetM, tetO, tetW, and tetX, as well as their expression levels, were quantified by quantitative PCR (qPCR) and reverse transcriptional PCR (RT-PCR). The correlations between TC concentrations and gene abundance of TC-ARGs and their expression levels were discussed. The results showed that the gene abundances of tetA, tetG, and tetW generally increased with increasing TC exposure concentrations during the entire culture cycle, whereas other TC-ARGs fluctuated greatly. The impact of TC stress on the transcriptional expression level of different TC-ARGs varied to a great extent. The gene expression of tetA was relatively stable and exhibited an upregulated trend with increasing TC concentrations. When the TC concentration was 100 mg·L-1, the upregulation of tetA expression was as high as 5.3-fold compared with the control. Under short-term TC stress (one day), the transcriptional expression level was upregulated with increasing TC concentration. The correlation results showed that gene abundances of tetA and tetW correlated significantly with their respective expression levels, indicating that they can evaluate expression levels to a certain extent, which can further mirror functional activities and environmental risks.

Zn-MOFs based luminescent sensors for selective and highly sensitive detection of Fe3+ and tetracycline antibiotic.

Either reduced or excessive metal ions level in biological systems might induce serious metabolic diseases, and the abuse of antibiotics has seriously affected the environment. Despite the significant progress in the development of fluorescence probes over the past decade, the ability to sensitively and selectively detect these metal ions and antibiotics remains a pressing problem. Herein, we demonstrated some effective fluorescence probes for sensing metal ions and antibiotics, six novel and stable Zn(II) metal-organic frameworks (Zn-MOFs), namely [Zn3(L)2(1,4-bimb)3]n (1), [Zn3(L)2(4,4'-bbibp)2(H2O)2]n·2(CH3CN) (2), [Zn(HL)(4,4'-bidpe)]n (3), [Zn(HL)(4,4'-bibp)]n (4), [Zn(HL)(3,5'-bip)]n (5) and [Zn(HL)(1,3'-bit)]n (6) (flexible H3L = 5-(2-carboxylphenoxy)isophthalic acid, semi-flexible 1,4-bimb = 1,4-bis(imidazol-l-ylmethyl) benzene, rigid 4,4'-bbibp = 4,4'-bis(benzoimidazo-1-ly)biphenyl, semi-flexible 4,4'-bidpe = 4,4'-bis(imidazolyl)diphenyl ether, rigid 4,4'-bibp = 4,4'-bis(imidazolyl)biphenyl, rigid 3,5'-bip = bis(1-imidazoly)pyridine and rigid 1,3-bit = 1,3-bis(l-imidazoly)toluene) have been successfully synthesized via solvothermal conditions and further characterized by IR spectra, elemental analysis, powder X-ray diffraction (PXRD), single-crystal X-ray diffraction, and thermogravimetric (TG) analysis. These Zn MOFs have exhibited diversely architectural frameworks via the assistant N-donor ligands: 1, 2, 5 and 6 show unprecedented topological networks, 1 affords a 3-nodal (3, 4, 4)-connect 2-fold interpenetrating topology structure with the Point Schläfli symbol of (5·6·7·92·10)2(5·6·7)2(5·73·82), 2 shows a 3-nodal (3, 4, 6)-c topology with (4·82)2(42·811·10·12)(86), 5 and 6 display 3-nodal (2, 2, 4)-c topology with (2·44·6)(2)(4). 3 and 4 show 4-connected sql topology with (44·62). As expected, Zn MOFs 1-6 not only revealed a highly sensitive and selective fluorescence quenching effect on Fe3+ ions in aqueous solution, but also toughed the interference of a myriad of other metal ions. It is noteworthy that they could also be used as luminescent sensors for detection of tetracycline antibiotic.

An online field-assisted micro-solid-phase extraction device coupled with high-performance liquid chromatography for the direct analysis of solid samples.

Herein, a total online device based on field-assisted extraction (FAE), micro-solid-phase extraction (µ-SPE), and high-performance liquid chromatography (HPLC) was designed. Solid samples were pretreated with ultrasound-microwave synergic effects, and then the extract was cleaned up online with a monolithic column, followed by HPLC analysis. The cross-actions between ultrasound and microwave along with other extraction parameters were studied systematically. The efficiency of this online method was verified in the determination of polycyclic aromatic hydrocarbons (PAHs) in foods and tetracycline antibiotics (TCAs) in cosmetic samples. The detection limits of nine PAHs including fluorene, phenanthrene, anthracene, fluoranthene, benzo[k]fluoranthene, benz[a]anthracene, benzo[b]fluoranthene, pyrene, and benzo[a]pyrene were all within 0.075-0.30 µg/kg, as well as four TCAs including oxytetracycline, tetracycline, chlortetracycline, and doxycycline were within 0.02-0.06 µg/kg. Six PAHs were found in roast potatoes and baked fish and the recoveries were in the range of 71.5-119.7% with RSDs of 0.2-10.9% (n = 3). The recoveries for TCAs in cosmetic samples were in the range of 75.3-118.0% with RSDs lower than 8.2% (n = 3). Compared with those offline methods, this total online FAE-µ-SPE-HPLC method not only simplifies the operation process, but also increases the precision and accuracy. Beyond trace analytes analysis in solid and semi-solid matrixes, application of this total online analysis method can also be extended to investigate field-assisted extraction mechanisms. Graphical abstract.

Phosphine production in anaerobic wastewater treatment under tetracycline antibiotic pressure.

The influence of tetracycline (TC) antibiotics on phosphine (PH3) production in the anaerobic wastewater treatment was studied. A lab-scale anaerobic baffled reactor with three compartments was employed to simulate this process. The reactor was operated in a TC-absence wastewater and 250µg/L TC-presence wastewater for three months after a start-up period, respectively. The responses of pH, oxidation-reduction potential (ORP), chemical oxygen demand (COD), total phosphorus (TP), enzymes activity (dehydrogenase and acid phosphatase), and microbial community were investigated to reveal the effect of TC on PH3 production. Results suggested that the dehydrogenase (DH) activity, acid phosphatase (ACP) activity and COD have positive relationship with PH3 production, while pH, ORP level and the TP in liquid phase have negative relationship with PH3 production. With prolonged TC exposure, decrease in pH and increase in DH activity are beneficial to PH3 production, while decrease in COD and ACP activity are not the limiting factors for PH3 production.

Effective removal of tetracycline from aqueous solution using activated carbon prepared from tomato (Lycopersicon esculentum Mill.) industrial processing waste.

Activated carbon (TAC) prepared under optimized conditions with ZnCl2 activation from a new precursor; tomato industrial processing waste (TW), was applied as an adsorbent to remove tetracycline (TC) from aqueous solution. The factors (TAC dosage, initial TC concentration, contact time, ionic strength and solution temperature) affecting the adsorption process were examined at natural pH (5.7) of TAC-TC system in aqueous solution. Kinetic data was found to be best complied by the pseudo-second order model. The isotherm analysis indicated that the equilibrium data could be represented by the Langmuir model. The maximum adsorption capacity was identified as 500.0mgg(-1) at 308K.

Dissipation kinetics of oxytetracycline, tetracycline, and chlortetracycline residues in soil.

The dissipation of different residual states of tetracycline antibiotics (TCs) including oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC) laboratory microcosm systems was investigated in this study. The residues were fractionated by stepwise extractions into aqueous state (KCl solution extracts), organic state (MeOH extracts), residual state I (citric acid-sodium citrate buffer and ethyl acetate extracts) and residual state II (acetonitrile-EDTA-McIlvaine buffer extracts) for accurate evaluation of TCs pollution. The antibiotics in the aqueous state were hardly detected, whereas the antibiotics in the organic state dissipated relatively fast (not detectable within 15 days after application) and followed simple first-order kinetics (SFOK) (R (2) from 0.929 to 0.990). While first-order double-exponential decay model (FODED) (R (2) from 0.840 to 0.999) and availability-adjusted first-order model (AAFO) (R (2) from 0.939 to 0.999) had a better fit on the dissipation of both residue state I and II than SFOK. TCs in these states were likely sequestered into a dormant undegradable phase since no degradation product was detected during the entire experiment. In addition, the overall 50 % dissipation values (i.e., stability) of the three TCs were OTC > TC > CTC. The TCs tend to dissipate faster in the high water content and organic matter soil.