Concentrations Of Ciprofloxacin Research Articles

Antibiotics pollutants in agricultural soil: Kinetic, sorption, and thermodynamic of ciprofloxacin

The entry of antibiotics, as pollutants, into the environment has created great concerns. Environmental dynamics of antibiotics based on soil chemical properties need to be a better understanding of their chemical behavior. This research is focused on studying the adsorption behavior and kinetic mechanisms of ciprofloxacin (CIP) in an agricultural soil. For this purpose, a batch experiment was conducted at different times (5 min–24 h), and using initial concentrations of CIP (0–1 mmol L−1) in the soil. The adsorption processes as affected by pH and ionic strength were assessed based on the modeling with response surface methodology (RSM). According to the results, the sorption equilibrium was found within 240 min, and the pseudo second-order model was the best for describing the data. Increasing the initial CIP concentration increased CIP adsorption, but increases in ionic strength and pH had an inverse effect. Based on RSM modeling, the CIP adsorption was 7.31 and 7.03 (mg g−1) in the presence of NaCl and CaCl2 electrolytes, respectively, in the optimized conditions (pH 6.5 and ionic strength 0.01 mol L−1). The spontaneous nature of CIP adsorption was determined based on thermodynamic calculations (ΔG° = −10.8 to −12.4 kJ mol−1). The interaction of pH and ionic strength was described with the quadratic model. The obtained results contribute to understanding the CIP fate in the soil environment and facilitate decisions regarding entry and controlling soil contamination due to this antibiotic.

BiVO4/sulfur-doped g-C3N4 nanocomposite as photocatalyst for degradation of ciprofloxacin under visible light irradiation

In recent years, the use of antibiotics has greatly increased, which has caused environmental pollution. We offer a photocatalyst based on BiVO4/sulfur-doped g-C3N4 nanocomposite, which was made by a one-step thermal condensation method from thiourea and bismuth vanadate to degradate ciprofloxacin (CIP). The BiVO4/sulfur-doped g-C3N4 photocatalyst was analyzed by certain techniques including XRD, FTIR, BET, FESEM, EDX, TEM, DRS, photoluminesence, and Mott-Schottky to determine various physicochemical properties. The photocatalytic degradation of CIP, as a model pollutant, under visible LED light irradiation was tested to investigate the catalytic performance of nanocomposite. Response Surface Methodology (RSM) was employed to optimize operational parameters, including photocatalyst dosage (50–150 mg), CIP concentration (10–30 mg/L), initial pH of the solution (3–11), and irradiation time (12–120 min). The BiVO4/sulfur-doped g-C3N4 nanocomposite, with a narrow bandgap of 2.15 eV, exhibited exceptional photocatalytic performance in degrading CIP. The optimal conditions for CIP removal were photocatalyst dosage of 120.9 mg, CIP concentration of 10 mg/L, and initial solution pH of 3, resulting in 93.5 % removal efficiency after 105 min of irradiation. The photocatalytic degradation kinetics of CIP followed a pseudo-first-order model with a rate constant (K) of −0.0221 L/min, indicating rapid degradation process. The photocatalyst maintained excellent performance after 5 reuses, with only a 3 % reduction in efficiency. XRD analysis confirmed the structural stability of the nanocomposite after reuse.

Association between maternal antibiotic exposure and emotional and behavioural problems in children at four years of age: A biomonitoring-based prospective study

BackgroundMaternal exposure to multiple antibiotics exposure during pregnancy has attracted extensive attention, but biomonitoring studies linking prenatal antibiotic exposure to emotional and behavioural problems in children are limited. MethodsA total of 2475 pregnant women from the Ma’anshan Birth Cohort were included, and the Strengths and Difficulties Questionnaire was completed when their children turned four years of age. The levels of 41 maternal urinary antibiotics and two metabolites were measured during the first, second and third trimesters. Generalized estimating equations and binary logistic regression models were applied to analyse the associations between maternal antibiotic exposure and emotional and behavioural problems in children and to determine the sensitive period, respectively. A quantile-based g-computation (QGC) approach was employed to examine the combined effects of multiple antibiotics on emotional and behavioural problems in children. ResultsOverall, florfenicol and preferred-as-veterinary antibiotic (PVA) exposure during pregnancy increased the risk of emotional problems in children, and ofloxacin exposure increased the risk of hyperactivity-inattention. Maternal exposure to trimethoprime, ciprofloxacin, florfenicol, other antibiotics and PVA exposure during the first trimester was positively associated with emotional problems in children. Second-trimester trimethoprime concentrations and third-trimester ciprofloxacin concentrations were positively associated with hyperactivity-inattention. Third-trimester veterinary antibiotic (VA) exposure was negatively associated with hyperactivity-inattention, and second-trimester VA and PVA exposure was negatively associated with peer problems. The QGC model revealed that mixed antibiotic exposure in the first trimester exacerbated the risk of childhood emotional problems (the contribution of ciprofloxacin is prominent), and mixed antibiotic exposure in the second trimester increased the risk of hyperactivity-inattention (the contribution of trimethoprime is prominent). ConclusionMaternal mixed antibiotic exposure during the first and second trimesters increases the risk of emotional problems and hyperactivity-inattention in children at four years of age.

Exploring the efficiency of nitrogenated carbon quantum dots/TiO2 S-scheme heterojunction in the photodegredation of ciprofloxacin in aqueous environments.

In this study, we developed a heterojunction photocatalyst, namely nitrogen-doped carbon quantum dots/titanium dioxide (N-CQDs/TiO2), for the effective and sustainable treatment of ciprofloxacin (CIP) antibiotic in aqueous solution. First, N-CQDs were prepared from a chitosan biopolymer with a green, facile, and effective hydrothermal carbonization technique and then anchored on the TiO2 surface via a hydrothermal process. The morphological, structural, and optical properties of the as-prepared materials were characterized by using advanced analytical techniques. The impacts of the mass percentage of N-CQDs, catalyst and CIP concentration, and pH on photocatalytic CIP degradation were investigated in depth. Comparative analyses were performed to evaluate different processes including adsorption, photolysis, and photocatalysis for the removal of CIP with TiO2 and N-CQDs/TiO2. The results revealed that N-CQDs/TiO2 exhibited the highest CIP removal efficiency of up to 83.91% within 120 min using UVA irradiation under optimized conditions (10 mg/L CIP, 0.4 g/L catalyst, and pH 5). Moreover, the carbon source used in the fabrication of N-CQDs was also considered, and lower removal efficiency was obtained when glucose was used as a carbon source instead of chitosan. This excellent improvement in CIP degradation was attributed to the ideal separation and migration of photogenerated carriers, strong redox capability, and high generation of reactive oxygen species provided by the successful construction of the N-CQDs/TiO2 S-scheme heterojunction. Scavenger experiments indicated that h+ and •OH reactive oxygen species were the predominant factors for CIP elimination in water. Overall, this study presents a green synthesis approach for N-CQDs/TiO2 heterojunction photocatalysts using natural materials, demonstrating potential as a cost-effective and efficient method for pharmaceutical degradation in water treatment applications.

Adsorption of ciprofloxacin from aqueous solutions using cellulose-based adsorbents prepared by sol-gel method

Ciprofloxacin (CIP) is one of the most widely used antibiotics to treat bacterial infections. Consequently, there is concern that it may contaminate water resources due to its high usage level. It is therefore necessary to monitor, trace, and reduce exposure to these antibiotic residues. In the current study, the extraction of CIP from water was performed using a green adsorbent material based on cellulose/polyvinyl alcohol (PVA) decorated with mixed metal oxides (MMO). This cellulose/MMO/PVA adsorbent was synthesized using a simple sol-gel method. The prepared adsorbent materials were then characterized using a range of methods, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, gas adsorption analysis, X-ray diffraction, and Fourier Transform infrared. The impact of pH, adsorbent dose, contact time, and CIP concentration on ciprofloxacin extraction were examined. The equilibrium and kinetic adsorption data were well described using the Freundlich model (R2 = 0.965). The optimum conditions for CIP adsorption were: pH = 4.5; adsorbent dosage = 0.55 g·L−1; contact time = 83 min; and initial CIP concentration = 2 mg·L−1. The adsorption capacity of the cellulose/MMO/PVA adsorbent for CIP removal was ∼19 mg·g−1 (CIP removal = 86.48 %). This study shows that cellulose/MMO/PVA adsorbents have potential for removing contaminants from aqueous environments.

Pharmacokinetics of Enrofloxacin and Its Metabolite Ciprofloxacin in Nanyang Cattle.

The objective of this study was to determine the pharmacokinetics of enrofloxacin and its metabolite, ciprofloxacin, in Nanyang cattle after a single intravenous (IV), and intramuscular (IM) administration of enrofloxacin at 2.5 mg/kg body weight (BW). Blood samples were collected at predetermined time points. Enrofloxacin and ciprofloxacin concentrations in plasma were simultaneously determined using a high-performance liquid chromatography (HPLC) assay method and subjected to a non-compartmental analysis. After IV administration, enrofloxacin had a mean (±SD) volume of distribution at steady state (VSS) of 1.394 ± 0.349 L/kg, a terminal half-life (t1/2λz) of 3.592 ± 1.205 h, and a total body clearance (Cl) of 0.675 ± 0.16 L/h/kg. After IM administration, enrofloxacin was absorbed relatively slowly but completely, with a mean absorption time (MAT) of 6.051 ± 1.107 h and a bioavailability of 99.225 ± 7.389%. Both compounds were detected simultaneously in most plasma samples following both routes of administration, indicating efficient biotransformation of enrofloxacin to ciprofloxacin. After IV injection, the peak concentration (Cmax) of ciprofloxacin was 0.315 ± 0.017 μg/mL, observed at 0.958 ± 0.102 h. Following IM injection, the corresponding values were 0.071 ± 0.006 μg/mL and 3 ± 1.095 h, respectively. Following IV and IM administration, the conversion ratio of enrofloxacin to ciprofloxacin was calculated as 59.2 ± 9.6% and 31.2 ± 7.7%, respectively. The present results demonstrated favorable pharmacokinetic profiles for enrofloxacin, characterized by complete absorption with relatively slow kinetics, extensive distribution, efficient biotransformation to ciprofloxacin, and prolonged elimination in Nanyang cattle.

A comprehensive assessment of water quality in Fayoum depression, Egypt: identifying contaminants, antibiotic pollution, and adsorption treatability study for remediation

This study aimed to assess the current water quality status across various regions within the Fayoum depression by examining water canals, drains, and potential contaminants impacting public health and the local ecosystem. Additionally, an adsorption treatability investigation was conducted on various antibiotics identified during the assessment. Fifteen sampling points were selected across the Fayoum depression, covering surface water bodies and agricultural drainage systems during both winter and summer seasons. Physico-chemical, microbiological, and antibiotic analyses were performed on collected water samples. The water quality parameters investigated included pH, electrical conductivity, total dissolved solids (TDS), total coliforms, fecal coliforms, and concentrations of antibiotics such as ciprofloxacin and tetracycline. The findings revealed significant variations in water quality parameters among different water sources, categorizing them into three types: irrigation canals, polluted canals, and drains. High contamination levels were observed in certain water canals and drains due to untreated sewage and agricultural drainage discharge. Notably, elevated TDS levels (exceeding 1200 mg/L), microbial indicators count (with total coliforms reaching up to 2.3 × 106 CFU/100 mL), and antibiotics (with concentrations of ciprofloxacin and tetracycline exceeding 4.6 µg/L) were detected. To mitigate antibiotic contamination, a Phyto-adsorption treatability study using magnetite nanoparticles prepared with Phragmites australis plant extract demonstrated promising results, achieving complete removal of high antibiotic concentrations with an adsorption capacity of up to 67 mg/g. This study provides updated insights into water quality in the Fayoum depression and proposes a novel approach for addressing antibiotic contamination, potentially safeguarding human and environmental health.

Photo-Fenton like catalyst system with CuCOFe2O4@AC nanoparticles for ciprofloxacin removal from aqueous solutions and effluent toxicity assessment by Escherichia coli and Enterococcus faecalis bacteria

In this study, the removal of the antibiotic ciprofloxacin (CIP) from aqueous solutions was investigated using the Photo-Fenton like (PFL) process and CuCOFe2O4@AC (CAC) magnetic nanoparticles as catalysts. First, CAC nanoparticles were synthesized and their characteristics were determined by XRD, VSM and FESEM, EDS, Mapping, FTIR. The removal efficiency of CIP in each of the nanomaterial processes, including UV, H2O2, CAC, UV+H2O2, CAC+H2O2 (Fenton like), and UV+CAC+H2O2 (PFL), were 1.0%, 7.97%, 61.37%, 6.0%, 73%, and 84%, respectively. Therefore, the PFL process was optimized as a suitable process, and the optimal conditions were determined as follows: H2O2 concentration of 2500 mg/L, pH of five, CAC dose of 600 mg/L, CIP concentration of 15 mg/L, and contact time of 50 min. The removal efficiency of CIP was achieved at 95.99%. The kinetic studies on the PFL process for the removal of CIP shown that the first order kinetic model exhibits better compatibility with the obtained results compared to other investigated kinetic models. Furthermore, the synergistic effect of the PFL process was equivalent to 1.8 times the individual processes. The results of microbiological tests in treated wastewater samples and control sample indicate the non-toxicity of residual pharmaceuticals wastewater on E. coli and E. faecalis bacteria. Due to the non-toxicity of the wastewater and the ability to recover nanoparticles using magnetism, as well as the possibility of recycling the nanoparticles, this technique can be effectively used as a suitable process in pharmaceutical industry wastewater treatment.

Improving oral delivery of ciprofloxacin through in situ spray drying and acid counterions

This study explores the application of a novel three-fluid nozzle spray drying technique in formulating in situ ciprofloxacin (CFX) salts for improved oral drug delivery. The used key materials in the study include CFX combined with four different counterions: succinic acid (SA), glutaric acid (GA), adipic acid (AA), and pimelic acid (PA), alongside hydroxypropyl methylcellulose (HPMC) as a matrix agent. The process utilized a three-fluid nozzle spray drying technique to produce CFX salts directly with these acids during the process, creating three types of formulations: pure salts (SALT), solutions of drug and polymer (SOL), and nanoprecipitates of drug within a polymer matrix (SUS). Powder X-ray Diffraction (PXRD) and Scanning Electron Microscopy (SEM) analyses revealed that the formulations predominantly exhibited an amorphous structure with varied particle shapes and sizes. The dissolution profiles of CFX salts show a marked burst release within the initial 5 min, with CFX-GA leading at nearly double the release rate of CFX-AA, after which all formulations rapidly achieve over 90 % dissolution and maintain a stable release up to 30 min. This pattern was attributed to the interactions between the drug salts and HPMC, resulting in a sustained release of CFX. In vivo experiments with rabbits revealed a higher plasma concentration of CFX for CGAH-sus compared to CGAH-sol, highlighting the enhanced bioavailability of the SUS formulation. The amorphous nature of CGAH-sus, with ionization confirmed through Raman spectroscopy, facilitated efficient drug release and absorption in the gastrointestinal tract. This study illustrates the effectiveness of the three-fluid nozzle spray drying method in producing salts with varied physical properties and dissolution profiles, holding potential for advanced oral drug delivery systems.

Linear and Nonlinear Approach on Kinetic Studies in the Adsorption of Ciprofloxacin onto Banana Peels-base Carbon from Aqueous Solution

The adsorption process investigates the adsorption kinetic of ciprofloxacin onto banana peels-based activated carbon (BPAC) with a batch process. The pyrolysis method prepared the banana peel-based activated carbon (BPAC). XRD investigated the crystallinity of the BPAC. The effect of shaking time, pH, concentration of BPAC, concentration of ciprofloxacin in aqueous solution, and time duration. The maximum removal percentage of ciprofloxacin from its aqueous solution was 98.7 %. In the kinetic study, the pseudo-first and second-order linear and non-linear equations were fitted with experimental data using the origin LAB program. The pseudo-first-order linear equation R2 values have an R2 of 0.9103. In contrast, the R2 values of the linear equations about pseudo-second-order of types I, II, III, and IV are 0.9982, 0.9968, 0.9986, and 0.9886, respectively. Considering the R2 values, linear pseudo-second-order types III & IV are preferable for ciprofloxacin elimination from its aqueous solution.

The Effect of Thickened Water on Ciprofloxacin Pharmacokinetics: A Comparative Study in Adult Males.

Background/Objectives: The use of food thickeners with ciprofloxacin tablets may result in a gelatinous appearance and experience delayed dissolution, which presents a challenge for the drug's efficacy, creating a healthcare economic issue. However, the pharmacokinetic impact of this compound in humans remains uncertain. Therefore, a comparative pharmacokinetic study of ciprofloxacin was conducted on healthy adult Japanese males. Methods: We compared the effects of administering tablets with water or thickened water and crushed tablets mixed with thickened water. The maximum blood concentration (Cmax) of ciprofloxacin determines the drug's efficacy. Results: There were variations in drug absorption across different administration methods. The group who took the tablets immersed in thickened water exhibited different results in the area under the blood drug concentration-time curve (AUC) and Cmax compared to the group who took the tablets in regular water. Notably, the group that consumed the crushed tablets mixed with thickened water demonstrated equivalent results for both AUC and Cmax. Conclusions: Administering crushed tablets in thickened water may yield pharmacokinetics comparable to those of tablets taken with water. However, the process of crushing tablets may result in the loss of active ingredients and compromise the formulation, necessitating a comprehensive assessment before administration.

Valorization of sponge iron industrial waste into iron-modified zeolite X for ciprofloxacin removal: a multi-parameter optimization study.

Ciprofloxacin (CIP), a commonly used antibiotic, is frequently detected in water bodies and the natural environment. The profound health consequences of CIP have led to growing attention focusing on environmental concerns. Adsorption is highly preferred because of its adaptability and remarkable efficiency in removing CIP. Therefore, the current work focuses on synthesizing an eco-friendly and economical adsorbent for removing CIP. The work aims to remove CIP using zeolite X (ZX), synthesized from dolochar, and subsequently modified ZX into iron-modified zeolite X (FeZX) via ion exchange. The synthesized FeZX had a crystallinity of 82.701%, an average pore size of 5.917 nm, a micropore volume of 0.298 cc/g, a micropore area of 451.807 m2/g, and a total surface area of 478.521 m2/g. The effect of parameters such as initial CIPconcentration, pH, contact period, adsorbent dosage, and iron dosage was analyzed in the batch adsorption studies of CIP using ZX and FeZX. CIP removal of 37.786% was achieved using ZX; hence, the adsorption parameters were optimized to maximize the CIP removal using response surface methodology (RSM), specifically Box-Behnken Design (BBD) using FeZX. Maximum removal of 97.974% was achieved under optimum conditions of 8.06 pH, contact period of 59.422 min, CIP concentration of 17.117 mg/L, and adsorbent dosage of 0.478 g/L. Freundlich isotherm and pseudo-second-order kinetic models werethe most accurate representations of the experimental data. The findings indicatethe significance of using this iron-modified mesoporous zeolite as an adsorbent for efficiently treating CIP wastewater.

Investigating the Z-scheme mechanism on the optimized oxygen vacancies ZnO/Co3S4 photocatalyst for the efficient photocatalytic removal of ciprofloxacin

The waste of human and animal antibiotics is an inescapable problem and a severe threat to the continuation of human life. A logical strategy to face the challenge of antibiotic contamination is to design active, stable, environmentally friendly, and economical photocatalysts. Hence, oxygen vacancies ZnO/Co3S4 (ZnO-OV/Co3S4) photocatalyst was successfully fabricated for the first time and used for the photocatalytic removal of ciprofloxacin (CIP) as a widely used antibiotic under visible light. Several techniques were engaged in exploring the crystallinity, morphology, structure, chemical and elemental composition, and electrochemical and optical properties of the constructed nanocomposites. The band gap of ZnO-OV and Co3S4 nanoparticles was determined at 2.95 and 1.58 eV by evaluating the optical properties and using the Tauc plots. To optimize the conditions of the photocatalytic process, factors such as the weight percentage of the nanocomposite components, the photocatalyst dosage, the initial concentration of CIP, the pH of the test solution, and the presence of bubbled oxygen were varied. The optimal degradation rate constant (0.0720 min−1) was obtained for ZnO-OV/Co3S4 (15 %) nanocomposite at pH 9, nanocomposite dosage of 1.5 g/L, and 10 mg/L of CIP in the visible spectrum. The experimental and characterization outcomes indicated that the significantly boosted photocatalytic activity of the ZnO-OV/Co3S4 composite was chiefly attributed to the oxygen vacancies, retard charge carriers recombination by the construction of heterojunction between the ZnO-OV and Co3S4. Finally, the possible Z-scheme mechanism was proposed to illuminate the migration of charge carriers.

In vitro antibacterial, antibiofilm activities, and phytochemical properties of Posidonia oceanica (L.) Delile: An endemic Mediterranean seagrass

In the antibiotic resistance era, utilizing understudied sources for novel antimicrobials or antivirulence agents can provide new advances against antimicrobial resistant pathogens. In this study, we aimed to investigate antibacterial and antibiofilm activities of Posidonia oceanica (L.) Delile against Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Klebsiella pneumoniae ATCC 700603 and several S. aureus clinical isolates obtained from medical devices, including patient urinary catheters and breast implant infections, with varying antibiotic recalcitrance profiles. The ethanolic and methanolic extracts from P. oceanica rhizome exhibited significant antibacterial activity against E. faecalis and S. aureus, as well as drug resistant S. aureus clinical isolates. Furthermore, significant antibiofilm activity was observed against S. aureus and E. faecalis treated with ER, MR1, and MR2. P. oceanica extracts also exhibited synergistic antimicrobial activity with ciprofloxacin against E. faecalis, sensitizing E. faecalis to a lower ciprofloxacin concentration. Collectively, our data demonstrate the selective antibacterial and antibiofilm activity of the extracts of P. oceanica against Gram-positive bacteria and clinical isolates along with potentiation of current antibiotics, which suggests that P. oceanica can be further investigated as a potential source for novel therapeutic options in the treatment of drug resistant bacterial infections.

Silver nanoparticle with potential antimicrobial and antibiofilm efficiency against multiple drug resistant, extensive drug resistant Pseudomonas aeruginosa clinical isolates

BackgroundThe study aims to investigate the effect of combining silver nanoparticles (AGNPs) with different antibiotics on multi-drug resistant (MDR) and extensively drug resistant (XDR) isolates of Pseudomonas aeruginosa (P. aeruginosa) and to investigate the mechanism of action of AGNPs.MethodsAGNPs were prepared by reduction of silver nitrate using trisodium citrate and were characterized by transmission electron microscope (TEM) in addition to an assessment of cytotoxicity. Clinical isolates of P. aeruginosa were collected, and antimicrobial susceptibility was conducted. Multiple Antibiotic Resistance (MAR) index was calculated, and bacteria were categorized as MDR or XDR. Minimum inhibitory concentration (MIC) of gentamicin, ciprofloxacin, ceftazidime, and AGNPs were determined. The mechanism of action of AGNPs was researched by evaluating their effect on biofilm formation, swarming motility, protease, gelatinase, and pyocyanin production. Real-time PCR was performed to investigate the effect on the expression of genes encoding various virulence factors.ResultsTEM revealed the spherical shape of AGNPs with an average particle size of 10.84 ± 4.64 nm. AGNPS were safe, as indicated by IC50 (42.5 µg /ml). The greatest incidence of resistance was shown against ciprofloxacin which accounted for 43% of the bacterial isolates. Heterogonous resistance patterns were shown in 63 isolates out of the tested 107. The MAR indices ranged from 0.077 to 0.84. Out of 63 P. aeruginosa isolates, 12 and 13 were MDR and XDR, respectively. The MIC values of AGNPs ranged from 2.65 to 21.25 µg /ml. Combination of AGNPs with antibiotics reduced their MIC by 5–9, 2–9, and 3-10Fold in the case of gentamicin, ceftazidime, and ciprofloxacin, respectively, with synergism being evident. AGNPs produced significant inhibition of biofilm formation and decreased swarming motility, protease, gelatinase and pyocyanin production. PCR confirmed the finding, as shown by decreased expression of genes encoding various virulence factors.ConclusionAGNPs augment gentamicin, ceftazidime, and ciprofloxacin against MDR and XDR Pseudomonas isolates. The efficacy of AGNPs can be attributed to their effect on the virulence factors of P. aeruginosa. The combination of AGNPs with antibiotics is a promising strategy to attack resistant isolates of P. aeruginosa.

A modified withdrawal time estimation and risk assessment of enrofloxacin in grass carp (Ctenopharyngodon idella) after ad libitum medicated feed based on statistical approaches in natural cultured environments.

Enrofloxacin (EF) is a broad-spectrum and highly efficient antibiotic commonly used for treating diseases in aquatic animals. However, its abuse in aquaculture applications often leads to excess residue in tissues of grass carp (Ctenopharyngodon idella). Hence, this study aimed to estimate the withdrawal time (WT) of EF and its metabolite of ciprofloxacin (CF) administered medicated feed in natural culture environments and conduct a risk assessment. Plasma and tissue samples were gathered at appropriate time points and detected by high-performance liquid chromatography. The data homogeneity was evaluated by Bartlett's test and Cochran's test. The linearity of the regressed line was evaluated by visual inspection and F test. Outliers were estimated on a normal probability scale by plotting the standardized residual versus their cumulative frequency distribution. Finally, the WT was calculated to be 51 days in muscle + skin based on the maximum residue limit of 100µg/kg. After 51 days, the concentration of EF and CF fell below 10µg/kg. The estimated daily intake was calculated to be 0.009µg/kg/d. Hazard quotient was computed to be 0.002, which was far below one. These results suggested that calculated WT of EF could ensure the safety of products from grass carp for humans.

Insight into the responses of performance, bacterial community and three-fraction resistance genes to different quaternary ammonium compounds in nitrifying system under the stress of environmental ciprofloxacin

In recently years, an increasing number of quaternary ammonium compounds (QACs) enter waster wastewater treatment plants (WWTPs), and coexist with the environmental antibiotics in WWTPs. In this study, dodecyl trimethyl ammonium chloride (ATMAC-C12), dodecyl benzyl dimethyl ammonium chloride (BAC-C12) and didodecyl dimethyl ammonium chloride (DADMAC-C12) were added to nitrifying system treating sewage containing environmental concentration of ciprofloxacin (CIP) (0.2 mg/L), respectively, to explore the different responses of resistance genes (RGs) under the co-occurrence of different kinds of QACs and CIP in nitrifying system. Results showed that partial nitrification was achieved by QACs and CIP co-loading, and the co-occurrence of ATMAC-C12 and CIP had more serious inhibitory in the ammonia oxidation activity, functional genes, extracellular polymeric substances (EPS), and bacterial community structures than BAC-C12 and DADMAC-C12 in nitrifying system. Moreover, the co-occurrence of ATMAC-C12 and CIP stimulated the proliferation of more intracellular RGs in sludge (si-RGs), while more extracellular RGs in sludge (se-RGs) and RGs in water (w-RGs) were enriched under the co-occurrence of DADMAC-C12 and CIP. Mobile genetic elements (MGEs) cooperated with bacteria to alter the profiles of RGs. Partial least-squares path model further confirmed that MGEs had positive effects on the proliferation and transmission of si/se/w-RGs (λ = 0.647, 0.918 and 0.627), and EPS had a most important effect (λ = 1.163) on the w-RGs under the co-occurrence of QACs and CIP. Therefore, it should pay attentions to the consumptions of QACs, and avoid the proliferation and transmission of RGs caused by the co-occurrence of QACs and environmental antibiotics.

Exploring Plasmid-Mediated Quinolone Resistance Gene Diversity among Ciprofloxacin-Resistant Proteus Species in a Tertiary Care Hospital of Bangladesh

Background: Increased resistance to fluoroquinolones has been observed in members of the Enterobacteriaceae, including Proteus species. The extensive use of fluoroquinolones and the presence of plasmid-mediated quinolone resistance (PMQR) genes are believed to contribute significantly to fluoroquinolone resistance. This study highlights the prevalence of ciprofloxacin-resistant Proteus species and the presence of specific PMQR genes among them, emphasizing their potential role in quinolone resistance. Method: The study included 30 ciprofloxacin-resistant Proteus isolates collected from wound swab, pus, urine, and blood samples. Identification of Proteus species was performed using culture and biochemical tests. Antibiotic susceptibility test was conducted using the Kirbey-Bauer disc-diffusion method. The minimum inhibitory concentration (MIC) of ciprofloxacin among ciprofloxacin-resistant Proteus species was determined using the agar dilution method. The study aimed to detect specific PMQR genes, namely aac(6´) lb-cr, qnrA, qnrB, qnrD, and qnrS, using polymerase chain reaction (PCR). Result: A total of 42 Proteus species were isolated from 310 various samples. Among the Proteus isolates, 71.43% were ciprofloxacin resistant. The study found that 30% of ciprofloxacin-resistant isolates were positive for aac(6´) lb-cr gene, 13.33% for qnrA and qnrS respectively and 10% for qnrD gene. In total, 60% of ciprofloxacin-resistant Proteus isolates were positive for at least one PMQR gene. The qnrB gene was not detected among ciprofloxacin-resistant Proteus species. The MIC of ciprofloxacin ranged from 8 μg/ml to 128 μg/ml among ciprofloxacin-resistant Proteus isolates. Conclusion: This study suggests aac(6´) lb-cr, qnrA, qnrS, and qnrD genes are emerging in Proteus species, potentially contributing to the development of quinolone resistance and has implications for clinical management and public health. J MEDICINE 2024; 25: 149-154

Red mud supported on rice husk biochar as sono-photo-Fenton catalysts for degradation of ciprofloxacin in water

To develop efficient methods to reuse red mud and rice husk waste to remove ciprofloxacin (CIP) in water, a simple and efficient Fenton catalyst based on red mud/rice husk biochar composite (RMR) was prepared using ultrasonic-assisted impregnation method. The effects of initial solution pH, initial CIP concentration, contact time, and catalyst dose on the removal of CIP in water were studied. The results showed that at pH 3, RMR dose of 1.0 g/L, CIP concentration of 20 mg/L, treatment time of 180 min, and temperature of 50 °C, the degradation efficiency was the highest at 75.97 % for sono-Fenton (SF) and 95.65 % for sono-photo-Fenton (SPF) with in situ generation of H2O2 during processes, indicating RMR has a great potential application in the treatment of organic pollution in actual wastewater. Other factors such as the co-existing anions (NO3–, SO42−, Cl−) or water matrices and other antibiotics were also investigated to prove the good removal of CIP by RMR for practical applications.

EFFECT OF CALCINATION TEMPERATURE VARIATION ON GREEN SYNTHESIS OF CADMIUM SULFIDE FOR CIPROFLOXACIN PHOTODEGRADATION

The green synthesis method has been successfully carried out to CdS with tea leaf extract and calcination temperature variation for the application of photocatalytic degradation of ciprofloxacin antibiotic. Variations in calcination at temperatures of 500, 600, and 700 ℃ were carried out to determine the effect of temperature on morphology and elemental composition, crystal structure and size, functional groups, and band gap energy by SEM-EDX, XRD, FTIR, and UV-DRS Spectrophotometer. The SEM-EDX image of the synthesized CdS is smooth and spherical and there is agglomeration with an even distribution of elements. The results of XRD and FTIR characterization showed the CdS peaks. The size of the CdS crystal increased with increasing temperature, namely CdS-600 at 64 nm and CdS-700 at 81.58 nm. The band gap energy value is influenced by the calcination temperature during synthesis with the band gap energy values of CdS-600 2.3 eV and CdS-700 2.38 eV. The percentage of CdS effectiveness with variations in calcination temperature in ciprofloxacin photodegradation is CdS-500 at 32.18%, CdS-600 at 48.72%, and CdS-700 at 8.73%. The optimum condition of CdS synthesis in degrading ciprofloxacin by photocatalytic process occurs at a temperature of 600℃ with a photocatalytic irradiation time under visible light for 120 minutes, a CdS mass of 10 mg, and an initial concentration of ciprofloxacin of 25 ppm. This result demonstrates the potential of an environmentally friendly method that can be applied in wastewater treatment.