Multiple Fluoroquinolones Research Articles

Excellent performance of a new stable LaCaCuFeO3 catalyst for the simultaneous removal of fluoroquinolone organic compounds in wastewater

This study designed LaCaCuFeO3 (LCCFO) by incorporating Ca into A sites of LaCuFeO3 (LCFO). LCCFO could efficiently activate peroxydisulfate (PDS) to simultaneous removal multiple fluoroquinolone organic compounds (FQs) in wastewater. In comparison to LCFO, the LCCFO could degrade 80 % of ciprofloxacin (CIP) and 100 % of ofloxacin (OFX) in 2 h with acceptable ion leaching. After four cycles, LCCFO retained its exceptional catalytic performance. During the reaction, the pHreaction increased from 4.4 to 6.7. Adjusting the pHreaction to 4.4 again at the end of the reaction could remove residual FQs. These findings provided a new insight into the treatment of wastewater with lower addition of PDS. Although the effects of inorganic anions on the removal of CIP and OFX were different, high concentration of Cl−, SO42−, HCO3− and H2PO4− at 10 g/L had a slight inhibitory effect on the reaction. The coexistence of radical and nonradical reaction pathways contributed to its excellent hypersaline tolerance. The LCCFO possessed good application prospects in wastewater treatment with hypersaline and complex pollutants.

Computational simulation-assisted template selection of magnetic MOFs molecularly imprinted materials applying the adsorption and detection of multiple fluoroquinolones

This study utilized computational simulation and surface molecular imprinting technology to develop a magnetic metal-organic framework molecularly imprinted polymer (Fe3O4@ZIF-8@SMIP) capable of selectively recognizing and detecting multiple fluoroquinolones (FQs). The Fe3O4@ZIF-8@SMIP material was synthesized using the “common” template-ofloxacin, identified by computational simulation, demonstrating notable adsorption capacity (88.61–212.93 mg g−1) and rapid mass-transfer features (equilibration time: 2–3 min) for all tested FQs, consistent with Langmuir adsorption model. Subsequently, this material was employed as a magnetic solid-phase-extraction adsorbent for adsorption and detection of multiple FQs by combining with high performance liquid chromatography. The developed method exhibited good linearity for various FQs within the concentration range of 0.1–500 μg L−1, with low limit of detection (0.0605–0.1529 μg L−1) and limit of quantitation (0.2017–0.5097 μg L−1). Satisfactory recoveries (88.38–103.44%) were obtained when applied to spiked food samples, demonstrating the substantial potential of this Fe3O4@ZIF-8@SMIP material for rapid enrichment and identification for multiple FQs residues.

Integrating target-responsive microfluidic-based biosensing chip with smartphone for simultaneous quantification of multiple fluoroquinolones

The presence of fluoroquinolone (FQs) antibiotic residues in the food and environment has become a significant concern for human health and ecosystems. In this study, the background-free properties of upconversion nanoparticles (UCNPs), the high specificity of the target aptamer (Apt), and the high quenching properties of graphene oxide (GO) were integrated into a microfluidic-based fluorescence biosensing chip (MFBC). Interestingly, the microfluidic channels of the MFBC were prepared by laser-printing technology without the need for complex preparation processes and additional specialized equipment. The target-responsive fluorescence biosensing probes loaded on the MFBC were prepared by self-assembly of the UCNPs-Apt complex with GO based on π-π stacking interactions, which can be used for the detection of the two FQs on a large scale without the need for multi-step manipulations and reactions, resulting in excellent multiplexed, automated and simultaneous sensing capabilities with detection limits as low as 1.84 ng/mL (enrofloxacin) and 2.22 ng/mL (ciprofloxacin). In addition, the MFBC was integrated with a smartphone into a portable device to enable the analysis of a wide range of FQs in the field. This research provides a simple-to-prepare biosensing chip with great potential for field applications and large-scale screening of FQs residues in the food and environment.

The Research Status, Potential Hazards and Toxicological Mechanisms of Fluoroquinolone Antibiotics in the Environment

Fluoroquinolone antibiotics are widely used in human and veterinary medicine and are ubiquitous in the environment worldwide. This paper recapitulates the occurrence, fate, and ecotoxicity of fluoroquinolone antibiotics in various environmental media. The toxicity effect is reviewed based on in vitro and in vivo experiments referring to many organisms, such as microorganisms, cells, higher plants, and land and aquatic animals. Furthermore, a comparison of the various toxicology mechanisms of fluoroquinolone antibiotic residues on environmental organisms is made. This study identifies gaps in the investigation of the toxic effects of fluoroquinolone antibiotics and mixtures of multiple fluoroquinolone antibiotics on target and nontarget organisms. The study of the process of natural transformation toward drug-resistant bacteria is also recognized as a knowledge gap. This review also details the combined toxicity effect of fluoroquinolone antibiotics and other chemicals on organisms and the adsorption capacity in various environmental matrices, and the scarcity of data on the ecological toxicology evaluation system of fluoroquinolone antibiotics is identified. The present study entails a critical review of the literature providing guidelines for the government to control the discharge of pollutants into the environment and formulate policy coordination. Future study work should focus on developing a standardized research methodology for fluoroquinolone antibiotics to guide enterprises in the design and production of drugs with high environmental biocompatibility.

Oxygen-functionalized Ti3C2 MXene/exfoliated montmorillonite supported S-scheme BiOBr/Bi2MoO6 heterostructures for efficient photocatalytic quinolone antibiotics degradation

Exploiting an excellent photocatalyst system with sufficient photogenerated charge separation and strong redox ability for efficient degradation of multiple fluoroquinolones (FQs) antibiotics was crucial but still a big challenge. The significant impacts of novel oxygen-functionalized Ti3C2 MXene/exfoliated montmorillonite (Ti3C2/MMTex) severed as a superior co-catalyst to boost the catalytic activity of single semiconductor was verified in our previous work. Based on that, the Bi2MoO6 particles/BiOBr nanosheets were ingeniously anchored onto multilayer O-functionalized Ti3C2/MMTex by the form of in-situ self-assembly via facile two-step microwave-assisted solvothermal process. Representative characterizations confirmed that Ti3C2/MMTex exhibited chemical stability and achieved transformation from surface F-terminal to O-terminal owing to the introduction of MMTex. Moreover, Ti3C2/MMTex supporter greatly decreased the accumulation and improved the morphology of Bi2MoO6/BiOBr S-scheme heterojunction. With extensive Bi2MoO6/BiOBr sheets embedding onto Ti3C2/MMTex, the quaternary BiOBr/Bi2MoO6/Ti3C2/MMTex catalyst displayed extraordinary coral reef-like structure, followed by abundantly exposing high-active {001} facets of BiOBr. Furthermore, owing to the Schottky/S-scheme double heterojunction linkage system, the multiple electrons transfer pathways formed over the quaternary composite effectively facilitated the separation of photogenerated charge carriers, thereby leading to the enhanced generation of •O2− and •OH. Hence, multiple FQs antibiotics degradation efficiency over BiOBr/Bi2MoO6/Ti3C2/MMTex all up to 90%, especially for levofloxacin (LEV), 99% LEV could be eliminated within 120 min. Besides, superior recyclability and stability were revealed in this quaternary composite. Notably, demethylation and piperazine ring-opening dominated LEV degradation pathway and the generated intermediates possessed lower toxicity and ecological risks. Our study further excavates multiple positive effects of Ti3C2/MMTex co-catalyst in constructing the efficient catalytic system, and supplies novelty tactics to engineer a stable non-noble meta/Bi-based semiconductor Schottky/S-scheme double heterojunction linkage system with compact interface contact.

Interfacial catalytic and mass transfer mechanisms of an electro-peroxone process for selective removal of multiple fluoroquinolones

Ferrite-modified carbonized metal-organic frameworks were prepared and employed as a gas diffusion cathode to assist the circulating electro-peroxone (EP) treatment of three mixed fluoroquinolones (FQs). The initiated reaction rates of possible reactive sites exemplified the priority of the selective removal of FQs by O3. The contributions of O3 to the oxidation of the parent FQs were over 99%, while HO was responsible for the oxidation of ozone-resistant transformation products and the total organic carbon removal. The adsorption and activation of H2O2 and O3 into HO were facilitated by abundant surface functional groups of the cathode, proper redox pairs (Fe2+/Fe3+ and Co2+/Co3+), high adsorption energy (–2.82 eV), and strong chemical bindings. The findings provided references to guide the improvement of electrocatalytic water treatment beyond limitations of conventional electrocatalysts by investigating experimentally and computationally HO formation, mass transfer, and selective removal mechanisms.

Rapid and simultaneous determination of three fluoroquinolones in animal-derived foods using excitation-emission matrix fluorescence coupled with second-order calibration method.

The matter of fluoroquinolone residues in various foods still arouses wide public concern nowadays. In the present work, the strategy of excitation-emission matrix (EEM) fluorescence data coupled with second-order calibration method based on alternating normalization-weighted error (ANWE) algorithm was used to determine ofloxacin, lomefloxacin and ciprofloxacin in milk powder, milk and beef. Owning the unique "second-order advantage", the ANWE-assisted analytical method was proved to successfully and eco-friendly resolve the overlapped fluorescence spectra of multi-component in complex food matrixes without tedious pretreatment steps and sophisticated high-cost instrumentations. The feasibility of the proposed method was validated by experiments. The average spiked recoveries of three fluoroquinolones range from 82.6% to 110.5% with relative standard deviations lower than 7.4%, and the limits of detection range from 0.18 and 2.41 ng mL-1. For further evaluation, analytical figures of merit such as sensitivity and selectivity, as well as the RSDs of intra-day (≦10.6%) and inter-day (≦9.4%) were calculated. The satisfactory analytical results demonstrated that the proposed strategy could be a competitive alternative for simple, rapid and simultaneous determination of multiple fluoroquinolones in animal-derived food samples.

Effect of Fluoroquinolones on Performance and Microbial Community of a Vertical Flow Constructed Wetland

In order to investigate the effect of multiple fluoroquinolones on the performance and microbial community of a constructed wetland, ofloxacin, norfloxacin, and ciprofloxacin were added to the influent of the vertical flow constructed wetland for two months. Results indicated that COD removal rate gradually decreased after adding antibiotics, with the minimum removal rate of 70.94%, followed by gradual recovery. TP removal rate also decreased, with some fluctuations, while ammonia removal remained stable. Fluoroquinolones thus have an important effect on COD and TP removal from the constructed wetland, but there is no evident effect on ammonia removal. Based on results of the Shannon index and Shannoneven index, there were no significant changes in the microbial community, while the Chao1 index increasing significantly. Comparing community composition before and after antibiotic addition, the relative abundance of Proteobacteria decreased from 44.90% to 34.12%, still maintaining its predominance, while Firmicutes increased from 2.55% to 10.55%. At the class level, β-Proteobacteria declined from 17.03% to 8.36%, while the relative abundance of Clostridia, Bacilli, and Bacteroidia increased from 0.50%, 1.85%, and 0.10% to 4.21%, 4.64%, and 2.56%, respectively. The genera Dechloromonas and Pseudarthrobacter decreased from 8.56% and 5.10% to 3.16% and 1.53%, respectively, while Trichococcus, Tessaracoccus, and Desulfovibrio increased from 0.66%, 0.03%, and 0.02% to 3.84%, 3.83%, and 2.06%, respectively. The microbial community of the constructed wetland thus changed under the pressure of multiple fluoroquinolones.

Simultaneous Raising of Rabbit Monoclonal Antibodies to Fluoroquinolones with Diverse Recognition Functionalities via Single Mixture Immunization.

Highly specific monoclonal and polyclonal antibodies are the key components in a diverse set of immunoassay applications, from research work to routine monitoring and analysis. In the current manuscript, combinatorial strategies for a single mixture immunization, screening and rabbit hybridoma cell technology were described. Fluoroquinolones (FQs) drugs were chosen as representative analytes. Six FQs were conjugated with bovine serum albumin and used as immunogens for subsequent immunization, while a mixture of all was injected for coimmunization. The hybridomas obtained against the individual and multiple FQs were used for the production of diverse varieties of rabbit monoclonal antibodies (RabMAbs) against the target analytes. As was proven by indirect competitive ELISA and quantitative lateral flow immunoassay, this approach opens a new way for simultaneously obtaining functional monoclonal antibodies which are capable of recognizing both individual and multiple analytes in a single preparation circle. This addresses various needs of different monitoring regulations as analytical methodology advances.

Simple, stable and sensitive electrogenerated chemiluminescence detector for high-performance liquid chromatography and its application in direct determination of multiple fluoroquinolone residues in milk

A simple, stable and sensitive electrogenerated chemiluminescence (ECL) detector was developed. It was based on tris(2,2-bipyridyl)ruthenium(II) (Ru(bpy) 3 2+) immobilized on the surface of a Pt wire with Nepem-105D ion exchange solution. The detector was prepared by inserting a Pt wire with immobilized Ru(bpy) 3 2+ (working electrode) into a capillary tube, followed by inserting another Pt wire (counter electrode) in this tube and sealing. ECL behavior was investigated using ofloxacin as an analyte. Under optimal conditions, stable ECL intensity was obtained. This detector has been used in HPLC-ECL for the determination of multiple target fluoroquinolone residues in milk. There is no post column reagent addition, which would dilute the analytes, potentially leading to chromatographic band-broadening. The system is very simple with low dead volume, low baseline and background noise, together with high sensitivity and stability. The as-prepared ECL detector, when was used for the determination of ofloxacin, pefloxacin, enrofloxacin and difloxacin in milk, demonstrated adequate sensitivity to allow quantification of trace FQ levels in commercial milk samples. One or more of the target FQ analytes were present at levels above the LOD of the new ECL detector in each and every one of the 22 milk samples analysed.

High prevalence of Fluoroquinolone- and Methicillin-resistant Staphylococcus pseudintermedius isolates from canine pyoderma and otitis externa in veterinary teaching hospital.

Recently, a total of 74 Staphylococcus pseudintermedius isolates were collected from clinical cases of canine pyoderma and otitis externa in Korea. In this study, we examined in vitro fluoroquinolone resistance among those isolates using a standard disk diffusion technique. The results demonstrated that approximately 18.9% to 27.0% of the isolates possessed bacterial resistance to both veterinary- and human-licensed fluoroquinolones except one isolate, including moxifloxacin (18.9% resistance), levofloxacin (20.3% resistance), ofloxacin (24.3% resistance), ciprofloxacin (25.7% resistance), and enrofloxacin (27.0% resistance). Most surprisingly, 14 out of 74 (18.9%) isolates were resistant to all the five fluoroquinolones evaluated. Moreover, a PCR detection of the methicillin resistance gene (mecA) among the 74 isolates revealed that 13 out of 25 (52.0%) mecA-positive isolates, but only 7 out of 49 (14.3%) mecA-negative isolates, were resistant to one or more fluoroquinones. Taken together, our results imply that bacterial resistance to both veterinary- and human-use fluoroquinolones becomes prevalent among the S. pseudintermedius isolates from canine pyoderma and otitis externa in Korea as well as that the high prevalence of the mecA-positive S. pseudintermedius isolates carrying multiple fluoroquinolone resistance could be a potential public health problem.

A new approach to quantitative NMR: Fluoroquinolones analysis by evaluating the chemical shift displacements

Quantitative NMR spectroscopy is always an attractive goal as the identity and quantity could be simultaneously determined. Although significant advancements have been achieved in this field it is common that all reported quantitative NMR methods perform the analysis by utilizing the average integral intensities of selected signals. During the calculation of the area under NMR peaks several response problems can occur which should always be treated carefully to overcome inaccuracies. In the method proposed in this work the quantitative information is obtained utilizing the measurement of selected protons chemical shift displacements which is a quite straightforward and highly reproducible process. The 1H NMR spectra of multiple fluoroquinolone (FQ) solutions revealed that the chemical shifts of protons, especially the aromatic ones, were concentration dependent for all tested compounds, as a result of extensive self-association phenomena. In the present work a novel methodology is described for the quantitation of several FQs based on this dependence. The proposed method was applied to Ciprofloxacin solutions over a wide range of concentrations. Evaluation of the obtained data presented acceptable characteristics regarding accuracy, precision, and robustness. The applicability limitations of this method were found to be posed by current instrumentation, mainly by the magnetic field frequency e.g. the slope of the response function achieved with a 400 MHz instrument was twice the one achieved at 200 MHz. The pH effect was negligible from pD 2.5 to 5.5. The phenomenon appeared in a pattern that can be applied for a plethora of drug categories revealing self-association phenomena in a range of concentration determined by the magnet strength of the instrument.

Failure of levofloxacin treatment in community-acquired pneumococcal pneumonia

BackgroundStreptococcus pneumoniae is the leading cause of community-acquired pneumonia (CAP). High global incidence of macrolide and penicillin resistance has been reported, whereas fluoroquinolone resistance is uncommon. Current guidelines for suspected CAP in patients with co-morbidity factors and recent antibiotic therapy recommend initial empiric therapy using one fluoroquinolone or one macrolide associated to other drugs (amoxicillin, amoxicillin/clavulanate, broad-spectrum cephalosporins). Resistance to fluoroquinolones is determined by efflux mechanisms and/or mutations in the parC and parE genes coding for topoisomerase IV and/or gyrA and gyrB genes coding for DNA gyrase. No clinical cases due to fluoroquinolone-resistant S. pneumoniae strains have been yet reported from Italy.Case presentationA 72-year-old patient with long history of chronic obstructive pulmonary disease and multiple fluoroquinolone treatments for recurrent lower respiratory tract infections developed fever, increased sputum production, and dyspnea. He was treated with oral levofloxacin (500 mg bid). Three days later, because of acute respiratory insufficiency, the patient was hospitalized. Levofloxacin treatment was supplemented with piperacillin/tazobactam. Microbiological tests detected a S. pneumoniae strain intermediate to penicillin (MIC, 1 mg/L) and resistant to macrolides (MIC >256 mg/L) and fluoroquinolones (MIC >32 mg/L). Point mutations were detected in gyrA (Ser81-Phe), parE (Ile460-Val), and parC gene (Ser79-Phe; Lys137-Asn). Complete clinical response followed treatment with piperacillin/tazobactam.ConclusionThis is the first Italian case of community-acquired pneumonia due to a fluoroquinolone-resistant S. pneumoniae isolate where treatment failure of levofloxacin was documented. Molecular analysis showed a group of mutations that have not yet been reported from Italy and has been detected only twice in Europe. Treatment with piperacillin/tazobactam appears an effective means to inhibit fluoroquinolone-resistant strains of S. pneumoniae causing community-acquired pneumonia in seriously ill patients.

Brevundimonas diminuta infections and its resistance to fluoroquinolones

To report infections caused by Brevundimonas diminuta and antibiotic studies of this Gram-negative bacterium. Seven patients with infection and eight bacterial strains were studied. Tests included antibiotic susceptibility and analysis of the DNA gyrase and topoisomerase genes and the effect of efflux pump inhibitor Phe-Arg-beta-naphthylamide (PANA). The patients all had underlying disease of cancer. The infections involved bloodstream (one case), intravascular catheter (four cases), urinary tract (one case) and pleural space (one case of empyema). Fever up to 39.2 degrees C characterized these infections, which resolved upon treatment by combination antibiotics. Microbiologically, all organisms were resistant to multiple fluoroquinolones and cefepime, but were susceptible to amikacin, imipenem and ticarcillin/clavulanate. These quinolone-resistant B. diminuta strains were probably selected out by the prophylactic use of a quinolone in six of these patients. Additionally, the B. diminuta type strain ATCC 11568(T) that was isolated before the quinolone era from water was also resistant to ciprofloxacin and intermediate to levofloxacin, suggesting intrinsic quinolone resistance. The DNA gyrase and topoisomerase of six analysed strains all contained GyrA Ala-83 and Met-87, GyrB Leu-466 or Thr-466, and ParC Gln-57, Val-66 and Ala-80 that were probably the cause of fluoroquinolone resistance. PANA had nearly negligible effect. B. diminuta is intrinsically resistant to fluoroquinolones and can be selected out to cause infections.

Resistance to multiple fluoroquinolones in a clinical isolate of Streptococcus pyogenes: identification of gyrA and parC and specification of point mutations associated with resistance.

A strain of Streptococcus pyogenes resistant to multiple fluoroquinolones was isolated from the blood of an immunocompromised patient. Resistance to fluoroquinolones in S. pyogenes has not been previously studied. Compared to 10 sensitive strains of S. pyogenes, the fluoroquinolone-resistant clinical isolate of S. pyogenes presented point mutations in gyrA, predicting that serine-81 was changed to phenylalanine and that methionine-99 was changed to leucine, and in parC, predicting that serine-79 was changed to tyrosine. The mechanism of fluoroquinolone resistance in this isolate of S. pyogenes appears to be analogous to previously reported mechanisms for Streptococcus pneumoniae.