Concentrations Of Enrofloxacin Research Articles

The effects of enrofloxacin exposure on responses to oxidative stress, intestinal structure and intestinal microbiome community of largemouth bass (Micropterus salmoides)

Antibiotic residues in the aquaculture environments may lead to antibiotic resistance, and potentially exert adverse effects on health of the non-target organisms and humans. In order to evaluate the effect of enrofloxacin of environmental concentrations on largemouth bass (Micropterus salmoides). Two hundred and seventy largemouth basses (with an average weight of 7.88 ± 0.60 g) were randomly divided into three groups, and separately exposed to 0, 1, 100 μg/L enrofloxacin (Control, ENR1, ENR100) for 30 days to detect the effect of enrofloxacin on the growth performance, oxidative stress, intestinal microbiota structure, inflammatory response and structure of the intestine. The results showed that ENR significantly reduced the final body weight (FBW) and weight gain rate (WGR), and increased feed conversion ratio (FCR) (P < 0.05). The histopathological analysis revealed that the villus width and muscular thickness of anterior intestine were significantly decreased with the increasing of enrofloxacin concentration. The activity of SOD was significantly increased at enrofloxacin stress, while CAT and POD activity were significantly decreased compared to control group (P < 0.05). The activities of lysozyme (LZM), alkaline phosphatase (AKP) and peroxidase (POD) in ENR1 was higher than that of control and ENR100 groups. Enrofloxacin treatment up-regulated the expression IL-1β and TNF-α, and down-regulated IL-10, and decreasing the expression level ZO-1, claudin-1, and occludin. Furthermore, the enrofloxacin treatment significantly decreased the intestinal bacterial diversity (P < 0.05). Exposure to 100 μg/L enrofloxacin obviously increased the relative abundance of Bacteroidota, Myxococcota, and Zixibacteria of fish gut, and reduced Firmicutes; 1 μg/L enrofloxacin considerably increased Bacteroidota, Myxococcota, and Actinobacteria, and reduced Firmicutes. The relative abundance of DTB120 and Elusimicrobiota was positively correlated with the occludin and claudin-1 gene. Taken together, exposure to enrofloxacin inhibited the growth of largemouth bass, influenced intestinal health, and induced dysbiosis of the intestinal microbiota.

Electrochemical Determination of Enrofloxacin Using an Electrode Composed of Graphite Nanosheets Fabricated by Expansion in Dimethyl Sulfoxide

A sensor based on graphite nanosheets was fabricated through the electrochemical expansion of a graphite electrode in dimethyl sulfoxide for the sensitive electrochemical determination of enrofloxacin. The modified electrode surface exhibited a distinctive structure of nanoplates, characterized by layer thickness ranging from a few nanometers to ten nanometers. The developed electrode displayed notable electrochemical properties, including a faster charge transfer rate and a larger electrochemically active surface area, which was 1.3 times greater compared to the unmodified electrode. As a result, the sensor improved square wave voltammetric signals for enrofloxacin, exhibiting a 2.4-fold enhancement compared to the unmodified electrode. By optimizing the experimental parameters such as electrode fabrication conditions, pH of analytical solution, and adsorption time for enrofloxacin, the sensor demonstrated good reproducibility and a strong linear correlation over two ranges of enrofloxacin concentrations from 0.05–0.15 μM and 0.1–20 μM. The limit of detection was determined to be 0.002 μM. The sensor was successfully employed for the determination of enrofloxacin in spiked surface water samples before and after treating enrofloxacin by a photocatalytic method. The obtained results exhibited consistency with those obtained using a liquid chromatography-tandem mass spectrometry reference method, and a high recovery rate of 105.5% further confirmed the reliability of the proposed method for enrofloxacin detection.

Comparative Pharmacokinetics of Intravenous Enrofloxacin in One- Six- And Twelve-Month-Old Sheep.

Enrofloxacin (ENR) is a fluoroquinolone antibiotic approved for use in sheep of all ages. The body composition and metabolic capability change with age. These changes may alter the pharmacokinetics of drugs and thus their effect. Therefore, the pharmacokinetics of drugs need to be established in target- age animals. To determine the pharmacokinetics of ENR and its active metabolite, ciprofloxacin (CIP), following a single intravenous administration of ENR at a dose of 10 mg/kg in different ages of sheep. The study was carried out in the one-, six- and twelve-month age period of the sheep. A single dose of 10 mg/kg ENR was administered intravenously through the jugular vein to sheep in all age periods. ENR and CIP plasma concentrations were determined using HPLC-UV and analyzed using a non-compartmental method. ENR was detected in the plasma until 36 h in one-month-old and up to 24 h in other ages. CIP was detected in the plasma up to 24 h in all age groups. The t1/2ʎz and Vdss were significantly higher in one-month-old sheep than in six and twelve-months old sheep. There was no difference in ClT and AUC values in different age groups. AUC0-∞CIP/AUC0-∞ENR ratios were higher in one-month-old than in six- and twelve-months sheep. The most important pharmacokinetic changes associated with aging in sheep are decreased Vdss and t1/2ʎz of ENR and the low ratio metabolizing of ENR to CIP. Pharmacokinetic/pharmacodynamic data showed that ENR after IV administration of 10 mg/kg dose provided the optimal AUC0-24/MIC90 ratios for E. coli, P. multocida and Mycoplasma spp. (>125) with MIC of 0.37 µg/mL and for S. aureus (>30) with MIC of 0.5 µg/mL in all ages of sheep.

Subcellular tissue-specific responses of Mytilus galloprovincialis to fluoroquinolone antibiotics

The study aimed to investigate the in vitro effects of the fluoroquinolone antibiotics (FQs) Ciprofloxacin (CIP), Enrofloxacin (ENR) and Danofloxacin (DAN) on the mussel Mytilus galloprovincialis exposed to environmentally relevant concentrations. In vitro exposure was performed on subcellular fractions of the digestive gland and gills through a multi-biomarker approach, which included the assessment of cellular damage, antioxidant and biotransformation enzyme activities, neurotoxicity, and DNA single-strand breaks (DNAssb). Results showed a decrease in protein carbonyl content in the gills when exposed to all concentrations of ENR. A significant overall decrease in the enzymatic activity of antioxidant defences was observed in the digestive gland exposed to the highest concentration of DAN and CIP, with a similar trend observed in the gills. Neurotoxicity was observed in the digestive gland at all tested concentrations of all FQs, but no effects were detected in the gills. DNAssb was evident in both tissues at all higher FQ concentrations.

Pharmacokinetics, withdrawal period and risk assessment of enrofloxacin in the northern snakehead (Channa argus) following bath administration.

Enrofloxacin (ENR) is widely used in aquaculture practice, but little is known about its pharmacokinetic, withdrawal period and dietary risk in fish via bath administration. The purpose of this study was to provide data support for the use of ENR bath therapy in the northern snakehead (Channa argus). The pilot study was carried out to evaluate the therapy concentrations of ENR in northern snakehead with immersion concentrations ranged from 5 to 40 mg/L for 6 h. Based on results of the pilot study, an ENR immersion concentration of 20 mg/L was used for the formal experiment. At this dose, the peak concentrations of ENR in plasma, muscle plus skin, liver and kidney were 4.85, 4.55, 3.87 and 7.42 μg/mL (or g), respectively. According to the AUC0-∞ values, the distribution of ENR in northern snakehead followed the order of kidney > plasma > liver > muscle + skin. The elimination of ENR in northern snakehead was very slow, the half-lives (T1/2λz ) were up to 90.31, 85.5, 104.56 and 120.9 h in plasma, muscle plus skin, liver and kidney, respectively. Ciprofloxacin (CIP) was not detected in any samples in the pilot study and was only occasionally detected in muscle plus skin and liver samples in formal experiment. Based on the calculated PK/PD index AUC/MIC and Cmax /MIC, the current bath treatment regimen will have a good therapeutic effect on infections caused by bacteria with MIC below 0.6 μg/mL. The dietary risk assessment suggested that there was a dietary risk (Hazard Quotients > 10%) until day 6 after bath treatment. It is mandatory for ENR to maintain a withdrawal period of at least 450°C-day in northern snakehead after bath treatment ceased.

Population pharmacokinetic analysis of enrofloxacin and its active metabolite ciprofloxacin after intravenous injection to cats with reduced kidney function.

It is unknown if enrofloxacin accumulates in plasma of cats with reduced kidney function. To determine if enrofloxacin and its active metabolite ciprofloxacin have reduced clearance in azotemic cats. Thirty-four cats hospitalized for clinical illness with variable degree of kidney function. Prospective study. After enrofloxacin (dose 5 mg/kg) administration to cats, sparse blood sampling was used to obtain 2 compartment population pharmacokinetic results using nonlinear mixed-effects modeling. Plasma enrofloxacin and ciprofloxacin concentrations were measured and summed to obtain the total fluoroquinolone concentration. A model of ciprofloxacin metabolism from enrofloxacin was created and evaluated for covariate effects on clearance, volume of distribution, and the metabolic rate of ciprofloxacin generation from enrofloxacin. Body weight was the only covariate found to affect total fluoroquinolone volume of distribution (effect 1.63, SE 0.19, P < .01) and clearance (effect 1.63, SE 0.27, P < .01). Kidney function did not have a significant effect on total fluoroquinolone clearance (median 440.8 mL/kg/h (range 191.4-538.0 mL/kg/h) in cats with normal kidney function, 365.8 mL/kg/h (range 89.49-1092.0 mL/kg/h) in cats with moderate kidney dysfunction, and 308.5 mL/kg/h (range 140.20-480.0 mL/kg/h) in cats with severe kidney dysfunction (P = .64). Blood urea nitrogen concentration influenced the metabolic generation of ciprofloxacin from enrofloxacin (effect 0.51, SE 0.08, P < .01), but other markers of kidney function did not. Adjustment of enrofloxacin dosage is not indicated for azotemic cats.

Pencil lead graphite electrochemically modified with polyglutamic acid as a sensor for detection of enrofloxacin in aqueous media

This study investigates the modification of pencil lead graphite electrodes with polyglutamic acid using an effective and fast static method to develop a sensor for the detection of enrofloxacin (ENR). The successful fabrication of pGA on the electrode surface was confirmed by scanning electron microscopy, energy dispersive X-ray analysis, and Fourier-transform infrared spectroscopy. The conditions of electrochemical modification, including the applied potentials and number of cycles in the potentiostatic process, were systematically investigated to determine their effects on the ENR electrochemical response. The pH of the electrolyte media was also explored to elucidate the electrochemical reaction mechanism of ENR. The developed electrochemical sensor was evaluated using square wave stripping voltammetry for ENR detection. Under optimal conditions, the sensor demonstrated good reproducibility with a relative standard deviation of 4.3% (from five measurements) for ENR signal detection. A linear relationship between ENR concentration and its peak current was observed in the concentration range of 0.1 to 5 μM, with a high correlation coefficient of 0.9988. The limit of detection for ENR using the sensor was 0.12 μM. Our findings provide valuable insights into the design and optimisation of pencil lead graphite electrode-based sensors for ENR detection in aqueous media.

Tolerability of Otic Solutions Containing Different Enrofloxacin Concentrations in Dogs with Healthy Ears.

Otitis externa (OE) is a common disease in dogs, and topical medications are the preferred treatment. Compounded solutions of enrofloxacin are commonly used in practice to treat bacterial OE; however, the tolerability of different concentrations of this antibiotic in the ear canals of dogs has not been evaluated. The objective of this study is to determine if a higher concentration of enrofloxacin applied to the external ear canal is clinically tolerated in dogs with healthy ears. Sixteen client-owned dogs with bilateral healthy ears and no previous history of OE were enrolled. Injectable enrofloxacin 2.27% diluted with sterile sodium chloride in 1:1 (11.35 mg/mL) and 2:1 (15 mg/mL) ratios were applied into the dogs' right and left ears, respectively, q 12 hr for 14 days. Based on video otoscopic examination, clinical score for canine OE (OTIS3) results before application were ≤1 for all dogs. During the study and at the conclusion, all scores remained ≤2, which is considered normal. No cytologic inflammatory cells were seen in any of the dogs' ears throughout the study. Different concentrations of enrofloxacin solution applied topically were well tolerated by dogs with healthy ears and can be considered for the treatment of dogs with bacterial OE.

Degradation of enrofloxacin by a novel Fe–N–C@ZnO material in freshwater and seawater: Performance and mechanism

In this study, we investigated the doping of Fe–N–C with ZnO (Fe–N–C@ZnO) to enhance its performance in the reduction of biological toxicity and degradation of enrofloxacin (ENR) in seawater. The steady-state/transient fluorescence analysis and free radical quenching test indicated an extremely low electron–hole recombination rate and the generation of reactive oxygen species in Fe–N–C@ZnO, leading to an improvement in the energy efficiency. We compared the ENR degradation efficiencies of Fe–N–C@ZnO and ZnO using both freshwater and seawater. In freshwater, Fe–N–C@ZnO exhibited a slightly higher degradation efficiency (95.00%) than ZnO (90.30%). However, the performance of Fe–N–C@ZnO was significantly improved in seawater compared to that of ZnO. The ENR degradation efficiency of Fe–N–C@ZnO (58.87%) in seawater was 68.39% higher than that of ZnO (34.96%). Furthermore, the reaction rate constant for ENR degradation by Fe–N–C@ZnO in seawater (7.31 × 10−3 min−1) was more than twice that of ZnO (3.58 × 10−3 min−1). Response surface analysis showed that the optimal reaction conditions were a pH of 7.42, a photocatalyst amount of 1.26 g L−1, and an initial ENR concentration of 6.56 mg L−1. Fe–N–C@ZnO prepared at a hydrothermal temperature of 128 °C and heating temperature of 300 °C exhibited the optimal performance for the photocatalytic degradation of ENR. Based on liquid chromatography–mass spectrometry analysis, the degradation processes of ENR were proposed as three pathways: two piperazine routes and one quinolone route.

Enrofloxacin (ENR) exposure induces lipotoxicity by promoting mitochondrial fragmentation via dephosphorylation of DRP1 at S627 site

Enrofloxacin (ENR) is a kind of widespread hazardous pollutant on aquatic ecosystems and causes toxic effects, such as disorders of metabolism, on aquatic animals. However, its potential mechanisms at an environmental concentration on metabolic disorders of aquatic organisms remain unclear. Herin, we found that hepatic lipotoxicity was induced by ENR exposure, which led to ENR accumulation, oxidative stress, mitochondrial fragmentation, and fatty acid transfer blockage from lipid droplets into fragmented mitochondria. ENR-induced lipotoxicity and mitochondrial β-oxidation down-regulation were mediated by reactive oxygen species (ROS). Moreover, dynamin-like protein 1 (DRP1) mediated ENR-induced mitochondrial fragmentation and changes of lipid metabolism. Mechanistically, ENR induced increment of DRP1 mitochondrial localization via dephosphorylating DRP1 at S627 and promoted its interaction with mitochondrial fission factor (MFF), leading to mitochondria fragmentation. For the first time, our study provides an innovative mechanistic link between hepatic lipotoxicity and mitochondrial fragmentation under ENR exposure, and thus identifies previously unknown mechanisms for the direct relationship between environmental ENR concentration and lipotoxicity in aquatic animals. Our study provides innovative insights for toxicological mechanisms and environmental risk assessments of antibiotics in aquatic environment.

Degradation characteristics of intracellular and extracellular ARGs during aerobic composting of swine manure under enrofloxacin stress

Composting has been widely recognized as an effective method for removing antibiotic resistance genes (ARGs) from livestock manure. This study investigated the variation in intracellular ARGs (iARGs) and extracellular ARGs (eARGs) during swine manure composting under low (31.44 ± 1.11 mg/kg DM) and high (176.76 ± 1.90 mg/kg DM) enrofloxacin concentration stress. After 25 days of composting, the rates of total iARG and eARG degradation reached 67.30% ∼ 96.13% and 54.70% ∼ 80.30%, respectively. The fluoroquinolone and multidrug ARGs that were degraded included intracellular and extracellular aac(6′)-ib-cr, qnrS, qnrD, parC, oqxB, acrA, acrB and tolC, but i-parE and e-parE were not eliminated. The main reason for degradation were the alteration of bacterial communities and mobile genetic elements (MGEs). The total absolute abundances of iARGs were higher than those of eARGs during composting. iARG degradation was driven by the death and succession of potential hosts, primarily including gram-negative bacteria. Composting time advancement played a greater role in facilitating the microbial succession. High temperatures promoted bacterial death, which caused the release of iARGs and generation of eARGs, but continuous high temperature led to more eARG degradation. The dynamics of longer-term eARGs were more strongly affected by extracellular MGEs (eMGEs), and it is more likely that eARGs enter the environment synchronously with eMGEs and persist in the environment at lower abundances via eMGEs. Once eARGs re-enter bacteria, they may become more mobile and dangerous. This study provides insights for facilitating the removal of ARGs in fertilizer utilization.

Comparative study of the toxicity mechanisms of quinolone antibiotics on soybean seedlings: Insights from molecular docking and transcriptomic analysis

The ecological effects of quinolone antibiotics (QNs) on non-target organisms have received widespread attention. The toxicological mechanisms of three common QNs, that is, enrofloxacin, levofloxacin, and ciprofloxacin, on soybean seedlings were investigated in this study. Enrofloxacin and levofloxacin caused significant growth inhibition, ultrastructural alterations, photosynthetic suppression, and stimulation of the antioxidant system, with levofloxacin exhibiting the strongest toxic effects. Ciprofloxacin (<1 mg·L−1) did not have a significant effect on the soybean seedlings. As the concentrations of enrofloxacin and levofloxacin increased, antioxidant enzyme activities, malondialdehyde content, and hydrogen peroxide levels also increased. Meanwhile, the chlorophyll content and chlorophyll fluorescence parameters decreased, indicating that the plants underwent oxidative stress and photosynthesis was suppressed. The cellular ultrastructure was also disrupted, which was manifested by swollen chloroplasts, increased starch granules, disintegration of plastoglobules, and mitochondrial degradation. The molecular docking results suggested that the QNs have an affinity for soybean target protein receptors (4TOP, 2IUJ, and 1FHF), with levofloxacin having the highest binding energy (−4.97, −3.08, −3.8, respectively). Transcriptomic analysis has shown that genes were upregulated under the enrofloxacin and levofloxacin treatments were mainly involved in ribosome metabolism and processes to synthesize oxidative stress-related proteins. Downregulated genes in the levofloxacin treatment were primarily enriched in photosynthesis-related pathways, indicating that levofloxacin significantly inhibited gene expression for photosynthesis. Genes expression level by quantitative real-time PCR analysis was consistent with the transcriptomic results. This study confirmed the toxic effect of QNs on soybean seedlings, and provided new insights into the environmental risks of antibiotics.

Rainbow trout (Oncorhynchus mykiss) physiological response to microplastics and enrofloxacin: Novel pathways to investigate microplastic synergistic effects on pharmaceuticals

Enrofloxacin (ENR) is a broad-spectrum antibiotic widely used due to its efficacy against pathogens. Microplastics (MPs) may bind to ENR and reduce its efficiency, whereas there would be an increase in its toxicity, bioavailability, and bio-accumulation rates. Therefore, the hypothesis is that the interaction between MPs and ENR can alter their toxicity and bioavailability. The subjective of this study is to examine the toxicity of various concentrations of ENR (0, 1.35, and 2.7 ml Kg−1 diet) and MPs (0, 1000, and 2000 mg Kg−1 diet) alone and in combination for 21 days. The rainbow trout (Oncorhynchus mykiss) is an economic aquaculture species used as an experimental model in ecotoxicology studies. Blood biochemical analytes indicated that ENR and MPs combination led to increasing enzymatic activity of each biomarker, except for gamma-glutamyl-transferase (GGT). Alterations related to triglycerides, cholesterol, glucose, urea, creatinine, total protein, and albumin blood contents were observed. An elevation in the levels of superoxide dismutase (SOD), malondialdehyde (MDA), and glucose 6-phosphate dehydrogenase (G6PDH) was found in the liver. In contrast, catalase (CAT) and glutathione peroxidase (GPx) levels decreased. Furthermore, a decline was observed in the cellular total antioxidant (ANT) levels. These findings suggested that ENR and MPs could affect fish health both independently and together. Consequently, the study determined that when both ENR and MPs were present in high concentrations, the toxicity of ENR was amplified, providing further evidence of the synergistic impact of MPs on ENR toxicity.

Elucidating facile biosorptive eradication of enrofloxacin: Equilibrium, kinetics, reusability, cost estimation, and safe disposal

AbstractIn the current investigation, superheated steam activated green coconut shell (Cocos nucifera) biochar (PAGCSB) has been used in sorptive expulsion of the pharmaceutical micro‐pollutant enrofloxacin (ENX) from water. Through a number of progressive studies in batch sorption process, the influence of some crucial parameters are evaluated toward efficacious remediation of ENX laden aqueous media by PAGCSB. The parameters studied are: contact time (5–20 h); mixing intensity (100–190 rpm); pH (1–9); initial ENX concentration (5–35 mg/L); temperature (15–40°C); and biosorbent dosage (2–5 g/L). The maximum ENX removal is 91.92% by using ENX initial concentration 20 mg/L; pH 7; temperature 30°C; biosorbent dose 4 g/L; stirring speed 150 rpm; and contact period 16 h. The repeated usability of spent biochar has been assessed and found to be 69.91% even after the fifth cycle. The pseudo‐second order kinetic model provided the best fit to the kinetic data. The Langmuir model showed the finest suit to the isotherm data. Adsorption capacity of the biosorbent was observed to be 2.32 mg/g. The current study on biosorptive riddance of ENX revealed a good level of randomness in the thermodynamic process which is found to be exothermic in nature. A wide‐scale utilization of the developed biosorbent has been well‐substantiated by the cost estimation. Finally, the safe disposal of spent biosorbent has been studied in accordance with the World Health Organization safety guidelines. Hence, superheated steam activated green coconut shell derived biochar could be a cost‐effective and competent sorbent material for ENX eradication from contaminated water.

Detection of enrofloxacin residues in dairy products based on their fluorescence quenching effect on AgInS2 QDs

Water-soluble AgInS2 (AIS) quantum dots (QDs) were successfully prepared through the one-pot water phase method with thioglycolic acid (TGA) as the stabilizing agent. Because enrofloxacin (ENR) effectively quenches the fluorescence of AIS QDs, a highly-sensitive fluorescence detection method is proposed to detect ENR residues in milk. Under optimal detection conditions, there was a good linear relationship between the relative fluorescence quenching amount (ΔF/F0) of AgInS2 with ENR and ENR concentration (C). The detection range was 0.3125–20.00 μg/mL, r = 0.9964, and the detection limit (LOD) was 0.024 μg/mL (n = 11). The average recovery of ENR in milk ranged from 95.43 to 114.28%. The method established in this study has advantages including a high sensitivity, a low detection limit, simple operation and a low cost. The fluorescence quenching mechanism of AIS QDs with ENR was discussed and the dynamic quenching mechanism of light-induced electron transfer was proposed.

P43 | Minimal inhibitory and bactericidal concentrations of gentamicin, enrofloxacin, colistin and Melaleuca armillaris essential oil against Pseudomonas aeruginosa isolated from canine otitis externa

Journal of Veterinary Pharmacology and TherapeuticsVolume 46, Issue S1 p. 106-106 POSTER PRESENTATIONS P43 | Minimal inhibitory and bactericidal concentrations of gentamicin, enrofloxacin, colistin and Melaleuca armillaris essential oil against Pseudomonas aeruginosa isolated from canine otitis externa First published: 11 June 2023 https://doi.org/10.1111/jvp.13322Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume46, IssueS1Special Issue: 15th International Congress of the European Association for Veterinary Pharmacology and Toxicology held Bruges, Belgium, July 2–5, 2023June 2023Pages 106-106 RelatedInformation

Effects of antibiotics (enrofloxacin) on microbial community of water and sediment in an aquatic ecological model.

In order to explore the impact of antibiotics (enrofloxacin) on microbial community in aquatic environment, an indoor aquatic ecological model was built, and different concentrations of enrofloxacin (0.05, 0.5, 5, and 50 mg/L) were added in the aquatic ecological model. In addition, the water and sediment samples were collected on the 0, 7, 30, and 60 days, and the changes in microbial community were studied through 16S rDNA high-throughput sequencing. The results showed that when the concentration of enrofloxacin was 50 mg/L, the relative abundance of Actinomycetes was increased. In the water, the bacterial richness and diversity communities first decreased and then gradually recovered with the passage of time; On the 7th day, the diversity and richness index of species in the treatment groups with enrofloxacin at 5 and 50 mg/L decreased to the lowest; On the 30th day, the diversity and richness index of species began to rise; On the 60th day, the diversity index and richness index of water species began to increase, while the diversity index and richness index of sediment species decreased. In conclusion, the addition of enrofloxacin negatively affected the microbial community structure in an indoor aquatic ecological model, 50 mg/L enrofloxacin could increase the relative abundance of Actinomycetes, and decrease the diversity and richness index of water and sediment.

A novel carbon dots synthesized based on easily accessible biological matrix for the detection of enrofloxacin residues

With the rise of nanomaterials in recent years, a variety of carbon dots (CDs) with good properties synthesized by chemicals have been developed. Herein, Enrofloxacin (ENR) can be detected by environmentally friendly poplar flower CDs (Pf-CDs). Based on the concept of green chemistry, the precursor material is waste poplar flower, which is an easilyobtainable plant biomass. Without any special treatment, the whole preparation process for Pf-CDs is quite simple. Meanwhile, the prepared Pf-CDs have outstanding properties such as brilliant luminous performance and good biocompatibility. The Pf-CDs are typically 6.40 nm in size, with excitation/emission wavelengths of 368/445 nm, respectively. It is worth noting that intermolecular hydrogen bonds are formed between Pf-CDs and ENR, leading to the occurrence of aggregation-induced-emission (AIE). The fluorescence signal of Pf-CDs showed a linear relationship with the added ENR concentration of 0.2–100 µM, with a detection limit of 0.076 µM. With a recovery rate of 94.8%-103.15%, it has shown its potentiality and wide application in the detection of ENR in dairy products and domestic water.

Artemisinin alters disposition regularities of enrofloxacin and its metabolite ciprofloxacin in channel catfish (Ictalurus punetaus) following combined oral administration

The aim of this investigation was to explore the effect of artemisinin (ART) on pharmacokinetic (PK) and tissue distribution characteristics of enrofloxacin (ENR) and ciprofloxacin (CIP) in channel catfish following combined and single medicine. The channel catfish in ENR group were treated with ENR, and the fish in ENR-ART group were orally co-administrated with ENR and ART. ENR and CIP concentrations in channel catfish were determined using ultra performance liquid chromatography, and PK parameters for ENR and CIP were calculated by WinNonlin software. Moreover, the multi-drug resistance 1 (MDR1) gene expression and cytochrome P-450 3A (CYP 3A) enzyme activities in channel catfish liver were measured. The results showed that lower ENR and CIP levels were observed in ENR-ART group than that in ENR group, and similar regularities in PK parameters were also found that Cmax, AUC and MRT values in ENR group were all greater than those in ENR-ART group. Furthermore, higher MDR1 gene expression and CYP 3A enzyme activities in channel catfish liver were observed in ENR-ART group than those in ENR group. The present investigation indicates that ART can reduce the ENR concentrations, accelerate the excretion of ENR and decrease the antibacterial efficacy of ENR in channel catfish.

Effect of Enrofloxacin on the Microbiome, Metabolome, and Abundance of Antibiotic Resistance Genes in the Chicken Cecum.

Enrofloxacin is an important antibiotic for the treatment of Salmonella infections in livestock and poultry. However, the effects of different concentrations of enrofloxacin on the bacterial and metabolite compositions of the chicken gut and changes in the abundance of resistance genes in cecum contents remain unclear. To investigate the effects of enrofloxacin on chickens, we orally administered different concentrations of enrofloxacin to 1-day-old chickens and performed 16S rRNA gene sequencing to assess changes in the gut microbiomes of chickens after treatment. The abundance of fluoroquinolone (FQ) resistance genes was measured using quantitative PCR. Metabolomics techniques were used to examine the cecal metabolite composition. We found that different concentrations of enrofloxacin had different effects on cecum microorganisms, with the greatest effect on cecum microbial diversity in the low-concentration enrofloxacin group at day 7. Enrofloxacin use reduced the abundance of beneficial bacteria such as Lactobacillaceae and Oscillospira. Furthermore, cecum microbial diversity was gradually restored as the chickens grew. In addition, enrofloxacin increased the abundance of resistance genes, and there were differences in the changes in abundance among different antibiotic resistance genes. Moreover, enrofloxacin significantly affected linoleic acid metabolism, amino acid metabolism, and signaling pathways. This study helps improve our understanding of how antibiotics affect host physiological activities and provides new insights into the rational use of drugs in poultry farming. The probiotics and metabolites that we identified could be used to modulate the negative effects of antibiotics on the host, which requires further study. IMPORTANCE In this study, we investigated changes in the cecum flora, metabolites, and abundances of fluoroquinolone antibiotic resistance genes in chickens following the use of different concentrations of enrofloxacin. These results were used to determine the effects of enrofloxacin on chick physiology and the important flora and metabolites that might contribute to these effects. In addition, these results could help in assessing the effect of enrofloxacin concentrations on host metabolism. Our findings could help guide the rational use of antibiotics and mitigate the negative effects of antibiotics on the host.