Batch injection analysis with amperometric detection for fluoroquinolone determination in urine, pharmaceutical formulations, and milk samples using a reduced graphene oxide-modified glassy carbon electrode.

In this work, the batch injection analysis system with amperometric detection using reduced graphene oxide as a modifier of glassy carbon electrode (GCE) was investigated for the simple, fast, and sensitive monitoring of levofloxacin (LEVO) and ciprofloxacin (CIPRO) in samples of pharmaceutical formulations, synthetic urine, and milk (low- and high-fat content). LEVO and CIPRO were quantified in seven samples using amperometric measurements at +1.10 V vs Ag/AgCl, KCl(sat). The developed methods showed excellent analytical performance with limits of detection of 0.30 and 0.16 µmol L-1, linear range from 3.0 to 50 µmol L-1 and 1.0 to 50 µmol L-1, relative standard deviation below 9.7 and 3.1%, and recovery ranges ranging from 80 to 107% and from 78 to 109% for LEVO and CIPRO, respectively. In addition, the minimum sample preparation (simple dilution) combined with a high analytical frequency (130 to 180 analyses per hour) can be highlighted. Thus, the methods are promising for implementation in routine analysis and quality control to different samples.

Comparative effect of ciprofloxacin and moxifloxacin on the modulation of bile acid profiles and gut microbiota in rats

Abstract Fluoroquinolones are an important class of antimicrobial agents to manage infectious diseases. However, knowledge about how host bile acids are modified by fluoroquinolones is limited. We investigated and compared the impact of fluoroquinolones on circulating bile acid profiles and gut microbiota from in vivo studies. We administered ciprofloxacin (100 mg/kg/day) or moxifloxacin (40 mg/kg/day) orally to male Wistar rats for seven days. Fifteen bile acids (BAs) from the serum and large intestine were quantified by HPLC-MS/MS. The diversity of gut microbiota after ciprofloxacin and moxifloxacin treatment was analyzed using high-throughput, next-generation sequencing technology. The two fluoroquinolone-treated groups had different BA profiles. Ciprofloxacin significantly reduced the hydrophobicity index of the BA pool, reduced secondary BAs, and increased taurine-conjugated primary BAs in both the serum and large intestine as compared with moxifloxacin. Besides, ciprofloxacin treatment altered intestinal microbiota with a remarkable increase in Firmicutes to Bacteroidetes ratio, while moxifloxacin exerted no effect. What we found suggests that different fluoroquinolones have a distinct effect on the host BAs metabolism and intestinal bacteria, and therefore provide guidance on the selection of fluoroquinolones to treat infectious diseases.

Fluoroquinolones and trace elements in poultry litter: estimation of environmental load based on nitrogen requirement for crops.

Poultry litter soil application contributes to sustainability of agricultural systems and is in accordance with the United Nations Sustainable Development Goals (UN-SDG). Poultry litter recommended rates are based on crop nitrogen (N) needs, however, their application can be a potential source of antibiotics and trace elements overload. The aim of the study was to estimate the role of poultry litter application on soil contamination by fluoroquinolones [enrofloxacin (ENR) and ciprofloxacin (CIP)] and trace elements, based on N requirements for crops. Analytical and sampling techniques were used to estimate the loads from poultry litter application. Only CIP was found in poultry litter samples (283 ± 124 µg kg-1) and its load was estimated to be of 9.89 ± 4.33 g ha-1, for the poultry litter application (35 t ha-1). The estimated loads (g ha-1) of trace elements were: Cr 9.19 ± 3.26, Ni 12.3 ± 4.93, Pb 22.0 ± 8.26, Cu 229 ± 85.6, Mn 691 ± 259 and Zn 1,011 ± 378. These estimates were 900% higher than those recommended by the technical guidance, while N exceeded 600% the recommended application. In order to achieve UN-SDGs, local policies to disseminate knowledge and technologies are required for consolidating sustainable agricultural practices.

Enhancement of ciprofloxacin degradation in aqueous system by heterogeneous catalytic ozonation.

Fluoroquinolones are extensively used in medicine due to their antimicrobial activity. Their presence in water inhibits microorganism activity in conventional wastewater treatment plants. This study aims to evaluate the technical feasibility of applying heterogeneous catalytic ozonation to eliminate ciprofloxacin (CIP) as a representative of fluoroquinolone antibiotics normally present in municipal wastewater discharges. Experiments were conducted in a semi-batch stirred slurry reactor, using 0.7 L of 100 mg L-1 CIP aqueous solution, at pH 3 and 30 °C. Experimental results show that single ozonation can easily oxidise CIP molecules (68%) within the first 5 min, leading to the generation of refractory oxidation by-products. However, when heterogeneous catalytic ozonation is applied using iron oxide supported on MFI synthetic zeolite, total degradation of CIP is observed at 5 min and a higher mineralisation rate is obtained. A novel sequential process is developed for CIP mineralisation. In a first step, a flash single ozonation is applied and CIP molecules are broken down. Then, a catalytic ozonation step is conducted by adding the Fe/MFI catalyst into the reactor. As a result of catalyst addition, 44% of Total Organic Carbon (TOC) is eliminated within the first 15 min, compared to single ozonation where only 13% of TOC removal is reached in the same time. The application of this sequential process to a real wastewater effluent spiked with CIP leads to 52% of TOC removal.

Effectiveness of tobramycin and ciprofloxacin against bacterial isolates in canine otitis externa in Uberaba, Minas Gerais / Eficácia de tobramicina e ciprofloxacina contra isolados bacterianos de otite externa canina em Uberaba, Minas Gerais

Canine otitis externa is a common and recurrent disease in domestic dogs. Although not being life threatening, it can result in the overuse of antibiotics, increased bacterial resistance and reduction of options for treatment. This study aimed to determine: the principal characteristics (age, race, and gender) of dogs affected by otitis externa; the most frequently bacteria identified as being associated with it and their antimicrobial resistance profiles. A total of 221 bacterial isolates were identified by morphological staining and biochemical processes and tested against eleven antibiotics. Among the 148 dogs diagnosed with otitis externa, 51.4% (76/148) were males and 48.6% (72/148) females. The cases were detected mainly in dogs with age above 7 years (54.7%; 81/148. Among the races examined, poodles were the most numerous (14.84%; 22/148). The most common bacteria found were: coagulase-negative Staphylococcus (StCN), 33.9% (75/221); coagulase-positive Staphylococcus (StCP), 19% (42/221); Proteus spp., 17.2% (38/221) and Pseudomonas aeruginosa, 9.5% (21/221). Simultaneous resistance to more than three classes of antimicrobials were most frequently detected in P. aeruginosa (61.9%; 13/21) and Proteus spp (39.47%; 15/38). According to data obtained from this study, two veterinary medications found to be most effective for topical treatment were tobramycin and ciprofloxacin.(AU)

A otite externa canina é uma doença comum e recorrente em cães domésticos. Embora não seja uma ameaça à vida, pode resultar no uso excessivo de antibióticos, aumento da resistência bacteriana e redução das opções de tratamento. Este estudo teve como objetivo determinar: as principais características (idade, raça e gênero) de cães afetados por otite externa; as bactérias mais frequentemente identificadas como associadas a enfermidade e seus perfis de resistência. Um total de 221 isolados bacterianos foram identificados por características morfo-tintoriais e testes bioquímicos, e posteriormente testados contra onze antibióticos. Entre os 148 cães com diagnóstico de otite externa, 51,4% (76/148) eram machos e 48,6% (72/148) fêmeas. Os casos foram detectados principalmente em cães com idade acima de 7 anos (54,7%; 81/148). Entre as raças examinadas, poodles foram os mais acometidos (14,84%; 22/148). As bactérias mais encontradas foram: Staphylococcus coagulase-negativo. (StCN), 33,9% (75/221), Staphylococcus coagulase-positiva (StCP), 19% (42/221), Proteus spp., 17,2% (38/221) e Pseudomonas aeruginosa, 9,5% (21/221) Resistência simultânea a mais de três classes de antimicrobianos foi mais frequentemente detectada em P. aeruginosa (61,9%; 13/21) e Proteus spp (39,47%; 15/38). Segundo os dados obtidos neste estudo, os antibióticos com maior capacidade de inibição do crescimento bacteriano in vitro foram tobramicina e ciprofloxacina.(AU)

Critical evaluation of third-order advantage with highly overlapped spectral signals. Determination of fluoroquinolones in fish-farming waters by fluorescence spectroscopy coupled to multivariate calibration.

In this work, the analytical performance of a third-order/four-way calibration is evaluated to model a highly overlapped system, where two spectral dimensions are extremely similar, and the results are then compared with the results of second-order/three-way calibration. The four-way data were obtained during the photodegradation of fluoroquinolones (ciprofloxacin, norfloxacin and flumequine) in the form of excitation-emission matrices and modeled by unfolded partial least squares coupled to residual trilinearization (U-PLS-RTL). According to the results, the model obtained with the second-order algorithm (unfolded partial least squares coupled to residual bilinearization: U-PLS-RBL) was unsatisfactory due to high spectral overlap. The third-order approach obtained a satisfactory fit and better figures of merit (LOD, REP, RMSEP, and sensitivity, among others) even in the presence of unexpected interferences due to third-order advantages. Finally, the analytical method based on third-order multivariate calibration was applied to quantify these fluoroquinolones in spiked fish-farming water samples. In this case, the third-order advantage allowed us to satisfactorily model the data and to quantify these compounds in this complex matrix, demonstrating the superior analytical performance of the high-order data that were evaluated.

Electrochemical degradation of the antibiotic ciprofloxacin in a flow reactor using distinct BDD anodes: Reaction kinetics, identification and toxicity of the degradation products.

The performances of distinct BDD anodes (boron doping of 100, 500 and 2500 ppm, with sp3/sp2 carbon ratios of 215, 325, and 284, respectively) in the electrochemical degradation of ciprofloxacin - CIP (0.5 L of 50 mg L-1 in 0.10 M Na2SO4, at 25 °C) were comparatively assessed using a recirculating flow system with a filter-press reactor. Performance was assessed by monitoring the CIP and total organic carbon (TOC) concentrations, oxidation intermediates, and antimicrobial activity against Escherichia coli as a function of electrolysis time. CIP removal was strongly affected by the solution pH (kept fixed), flow conditions, and current density; similar trends were obtained independently of the BDD anode used, but the BDD100 anode yielded the best results. Enhanced mass transport was achieved at a low flow rate by promoting the solution turbulence within the reactor. The fastest complete CIP removal (within 20 min) was attained at j = 30 mA cm-2, pH = 10.0, and qV = 2.5 L min-1 + bypass turbulence promotion. TOC removal was practically accomplished only after 10 h of electrolysis, with quite similar performances by the distinct BDD anodes. Five initial oxidation intermediates were identified (263 ≤ m/z ≤ 348), whereas only two terminal oxidation intermediates were detected (oxamic and formic acids). The antimicrobial activity of the electrolyzed CIP solution was almost completely removed within 10 h of electrolysis. The characteristics of the BDD anodes only had a marked effect on the CIP removal rate (best performance by the least-doped anode), contrasting with other data in the literature.

Feasibility of anaerobic packed and structured-bed reactors for sulfamethoxazole and ciprofloxacin removal from domestic sewage.

This study assessed the applicability of fixed bed bioreactors in two configurations - anaerobic structured bed reactor (ASBR) and anaerobic packed bed reactor (APBR) - in the removal of Sulfamethoxazole (SMX) and Ciprofloxacin (CIP), two antibiotics frequently detected in sanitary sewage. The problem of these pharmaceuticals as emerging contaminants in conventional sewage treatment systems is mainly because they encourage the development and spread of resistance genes in bacteria. Both reactors had similar performances, and the antibiotics were highly removed - APBR: 85 ±â€¯10% for SMX and 81 ±â€¯16% for CIP; ASBR: 83 ±â€¯12% for SMX and 81 ±â€¯15% for CIP. The ASBR showed to be potentially more feasible in operating and economic terms compared to the APBR, as the former presents a smaller amount of support material in the bed. SMX was completely biotransformed, while the influence of the sorption mechanism was observed for CIP, as its presence was detected sorbed onto biomass throughout the reaction bed of the reactors, with a partition coefficient (log KD) of around 2.8 L·kg-1TSS. The degradation kinetics of the pharmaceuticals were fitted using a first-order kinetic model, whereby the reactors behaved as plug flow ones, indicating the possibility of optimizing the operation for a hydraulic retention time of 6 h. The removal kinetics was more favorable for CIP (higher apparent constant kinetic - kCIPapp > kSMXapp), since its biodegradation is linked to the biomass, which is more concentrated in the bed bottom layer. The experimental results showed the potential of anaerobic fixed bed reactors in removing environmentally relevant concentrations of SMX and CIP found in sewage.

Optimization of the electrochemical degradation process of the antibiotic ciprofloxacin using a double-sided ß-PbO2 anode in a flow reactor: kinetics, identification of oxidation intermediates and toxicity evaluation.

The electrochemical degradation of ciprofloxacin-CIP (50 mg L-1 in 0.10 mol L-1 Na2SO4) was investigated using a double-sided Ti-Pt/ß-PbO2 anode in a filter-press flow reactor, with identification of oxidation intermediates and follow-up of antimicrobial activity against Escherichia coli. The effect of solution pH, flow rate, current density, and temperature on the CIP removal rate was evaluated. All of these parameters did affect the CIP removal performance; thus, optimized electrolysis conditions were further explored: pH = 10, qV = 6.5 L min-1, j = 30 mA cm-2, and θ = 25 °C. Therefore, CIP was removed within 2 h, whereas ~75% of the total organic carbon concentration (TOC) was removed after 5 h and then, the solution no longer presented antimicrobial activity. When the electrochemical degradation of CIP was investigated using a single-sided boron-doped diamond (BDD) anode, its performance in TOC removal was similar to that of the Ti-Pt/ß-PbO2 anode; considering the higher oxidation power of BDD, the surprisingly good comparative performance of the Ti-Pt/ß-PbO2 anode was ascribed to significantly better hydrodynamic conditions attained in the filter-press reactor used with this electrode. Five initial oxidation intermediates were identified by LC-MS/MS and completely removed after 4 h of electrolysis; since they have also been determined in other degradation processes, there must be similarities in the involved oxidation mechanisms. Five terminal oxidation intermediates (acetic, formic, oxamic, propionic, and succinic acids) were identified by LC-UV and all of them (except acetic acid) were removed after 10 h of electrolysis.

Effectiveness of tobramycin and ciprofloxacin against bacterial isolates in canine otitis externa in Uberaba, Minas Gerais / Eficácia de tobramicina e ciprofloxacina contra isolados bacterianos de otite externa canina em Uberaba, Minas Gerais

Canine otitis externa is a common and recurrent disease in domestic dogs. Although not being life threatening, it can result in the overuse of antibiotics, increased bacterial resistance and reduction of options for treatment. This study aimed to determine: the principal characteristics (age, race, and gender) of dogs affected by otitis externa; the most frequently bacteria identified as being associated with it and their antimicrobial resistance profiles. A total of 221 bacterial isolates were identified by morphological staining and biochemical processes and tested against eleven antibiotics. Among the 148 dogs diagnosed with otitis externa, 51.4% (76/148) were males and 48.6% (72/148) females. The cases were detected mainly in dogs with age above 7 years (54.7%; 81/148. Among the races examined, poodles were the most numerous (14.84%; 22/148). The most common bacteria found were: coagulase-negative Staphylococcus (StCN), 33.9% (75/221); coagulase-positive Staphylococcus (StCP), 19% (42/221); Proteus spp., 17.2% (38/221) and Pseudomonas aeruginosa, 9.5% (21/221). Simultaneous resistance to more than three classes of antimicrobials were most frequently detected in P. aeruginosa (61.9%; 13/21) and Proteus spp (39.47%; 15/38). According to data obtained from this study, two veterinary medications found to be most effective for topical treatment were tobramycin and ciprofloxacin.

A otite externa canina é uma doença comum e recorrente em cães domésticos. Embora não seja uma ameaça à vida, pode resultar no uso excessivo de antibióticos, aumento da resistência bacteriana e redução das opções de tratamento. Este estudo teve como objetivo determinar: as principais características (idade, raça e gênero) de cães afetados por otite externa; as bactérias mais frequentemente identificadas como associadas a enfermidade e seus perfis de resistência. Um total de 221 isolados bacterianos foram identificados por características morfo-tintoriais e testes bioquímicos, e posteriormente testados contra onze antibióticos. Entre os 148 cães com diagnóstico de otite externa, 51,4% (76/148) eram machos e 48,6% (72/148) fêmeas. Os casos foram detectados principalmente em cães com idade acima de 7 anos (54,7%; 81/148). Entre as raças examinadas, poodles foram os mais acometidos (14,84%; 22/148). As bactérias mais encontradas foram: Staphylococcus coagulase-negativo. (StCN), 33,9% (75/221), Staphylococcus coagulase-positiva (StCP), 19% (42/221), Proteus spp., 17,2% (38/221) e Pseudomonas aeruginosa, 9,5% (21/221) Resistência simultânea a mais de três classes de antimicrobianos foi mais frequentemente detectada em P. aeruginosa (61,9%; 13/21) e Proteus spp (39,47%; 15/38). Segundo os dados obtidos neste estudo, os antibióticos com maior capacidade de inibição do crescimento bacteriano in vitro foram tobramicina e ciprofloxacina.

Sample preparation combined with electroanalysis to improve simultaneous determination of antibiotics in animal derived food samples.

A procedure based on liquid-liquid extraction (LLE) and phase separation using magnetically stirred salt-induced high-temperature liquid-liquid extraction (PS-MSSI-HT-LLE) was developed to extract and pre-concentrate ciprofloxacin (CIPRO) and enrofloxacin (ENRO) from animal food samples before electroanalysis. Firstly, simple LLE was used to extract the fluoroquinolones (FQs) from animal food samples, in which dilution was performed to reduce interference effects to below a tolerable threshold. Then, adapted PS-MSSI-HT-LLE protocols allowed re-extraction and further pre-concentration of target analytes in the diluted acid samples for simultaneous electrochemical quantification at low concentration levels. To improve the peak separation, in simultaneous detection, a baseline-corrected second-order derivative approach was processed. These approaches allowed quantification of target FQs from animal food samples spiked at levels of 0.80 to 2.00 µmol L-1 in chicken meat, with recovery values always higher than 80.5%, as well as in milk samples spiked at 4.00 µmol L-1, with recovery values close to 70.0%.

Optimization of ciprofloxacin degradation in wastewater by homogeneous sono-Fenton process at high frequency.

Emerging pollutants such as pharmaceuticals have been focusing international attention for a few decades. Ciprofloxacin (CIP) is a common drug that is widely found in hospital and wastewater treatment plants effluents, as well as in rivers. In this work, the feasibility of CIP degradation by ultrasound process at high frequency is discussed and sonolysis, sonolysis with hydrogen peroxide and sono-Fenton are evaluated. The amounts of hydrogen peroxide and ferrous ions (Fe2+) needed were optimized using response surface methodology. Best results were obtained with the sono-Fenton process resulting in a total pharmaceutical degradation within 15 min and a mineralization greater than 60% after 1 h. Optimal conditions were tested on a real matrix from a municipal wastewater treatment plant. Even if the degradation of the pollutants by sono-Fenton was hampered, the removal efficiency of both CIP and total organic carbon (TOC) is interesting as an increase in the biodegradability of the wastewater is found. These results show that sono-Fenton oxidation can be a promising pretreatment process for pharmaceutical-containing wastewaters.

Simultaneous determination of paracetamol and ciprofloxacin in biological fluid samples using a glassy carbon electrode modified with graphene oxide and nickel oxide nanoparticles.

A simple and highly selective electrochemical method using a glassy carbon electrode (GCE) modified with graphene oxide (GO) and nickel oxide nanoparticles (NiONPs) was developed for the simultaneous determination of paracetamol (PAR) and ciprofloxacin (CIP). The electrochemical characterisation of the modified GCE was performed by cyclic voltammetry and electrochemical impedance spectroscopy. The morphological characterisation of the GO and NiONPs was performed by scanning electron microscopy and transmission electron microscopy. Under optimised conditions, using square wave voltammetry, the simultaneous determination of PAR and CIP using the NiONPs-GO-CTS: EPH/GCE sensor shows a linear concentration range from 0.10 to 2.9µmolL-1 and 0.040-0.97µmolL-1, with detection limits of 6.7 and 6.0 nmol L-1, respectively. The NiONPs-GO-CTS: EPH/GCE sensor showed good reproducibility, repeatability and stability. Furthermore, the proposed method was successfully applied for the simultaneous determination of PAR and CIP in synthetic biological fluid samples.

Influence of dihydroxybenzenes on paracetamol and ciprofloxacin degradation and iron(III) reduction in Fenton processes.

The degradation of paracetamol (PCT) and ciprofloxacin (CIP) was compared in relation to the generation of dihydroxylated products, Fe(III) reduction and reaction rate in the presence of dihydroxybenzene (DHB) compounds, or under irradiation with free iron (Fe3+) or citrate complex (Fecit) in Fenton or photo-Fenton process. The formation of hydroquinone (HQ) was observed only during PCT degradation in the dark, which increased drastically the rate of PCT degradation, since HQ formed was able to reduce Fe3+ and contributed to PCT degradation efficiency. When HQ was initially added, PCT and CIP degradation rate in the dark was much higher in comparison to the absence of HQ, due to the higher and faster formation of Fe2+ at the beginning of reaction. In the absence of HQ, no CIP degradation was observed; however, when HQ was added after 30 min, the degradation rate increased drastically. Ten PCT hydroxylated intermediates were identified in the absence of HQ, which could contribute for Fe(III) reduction and consequently to the degradation in a similar way as HQ. During CIP degradation, only one product of hydroxyl radical attack on benzene ring and substitution of the fluorine atom was identified when HQ was added to the reaction medium.

Sulfamethoxazole and ciprofloxacin removal using a horizontal-flow anaerobic immobilized biomass reactor.

The antibiotics sulfamethoxazole (SMTX) and ciprofloxacin (CIP) are commonly used in human and veterinary medicine, which explains their occurrence in wastewater. Anaerobic reactors are low-cost, simple and suitable technology to wastewater treatment, but there is a lack of studies related to the removal efficiency of antibiotics. To overcome this knowledge gap, the objective of this study was to evaluate the removal kinetics of SMTX and CIP using a horizontal-flow anaerobic immobilized biomass reactor. Two different concentrations were evaluated, for SMTX 20 and 40 µg L(-1); for CIP 2.0 and 5.0 µg L(-1). The affluent and effluent analysis was carried out in liquid chromatography/tandem mass spectrometry (LC-MS/MS) with the sample preparation procedure using an off-line solid-phase extraction. This method was developed, validated and successfully applied for monitoring the affluent and effluent samples. The removal efficiency found for both antibiotics at the two concentrations studied was 97%. Chemical oxygen demand (COD) exhibited kinetic constants that were different from that observed for the antibiotics, indicating the absence of co-metabolism. Also, though the antibiotic concentration was increased, there was no inhibitory effect in the removal of COD and antibiotics.

Simultaneous determination of fluoroquinolones in environmental water by liquid chromatography-tandem mass spectrometry with direct injection: A green approach.

This work describes an on-line multi-residue method for simultaneous quantification of ciprofloxacin, enrofloxacin, gemifloxacin, moxifloxacin, norfloxacin and ofloxacin in superficial and wastewater samples. For that, an octyl restricted-access media bovine serum albumin column (RAM-BSA C8) was used for sample clean-up, enrichment and analysis with quantitation carried out by tandem mass spectrometry. For water samples volumes of only 500µL the method provided good selectivity, extraction efficiency, accuracy, and precision with quantification limits in the order of 20-150ngL(-1). Out of the six fluoroquinolones only ciprofloxacin (195ngL(-1)) and norfloxacin (270ngL(-1)) were quantified in an influent sample of the wastewater treatment plant (WWTP) of São Carlos (SP, Brazil). None were found in the superficial water samples analyzed. The capability of injecting native sample in an automated mode provides high productivity and represents a greener approach in environmental sample analysis.

The Successive Projections Algorithm for interval selection in trilinear partial least-squares with residual bilinearization.

In this work the Successive Projection Algorithm is presented for intervals selection in N-PLS for three-way data modeling. The proposed algorithm combines noise-reduction properties of PLS with the possibility of discarding uninformative variables in SPA. In addition, second-order advantage can be achieved by the residual bilinearization (RBL) procedure when an unexpected constituent is present in a test sample. For this purpose, SPA was modified in order to select intervals for use in trilinear PLS. The ability of the proposed algorithm, namely iSPA-N-PLS, was evaluated on one simulated and two experimental data sets, comparing the results to those obtained by N-PLS. In the simulated system, two analytes were quantitated in two test sets, with and without unexpected constituent. In the first experimental system, the determination of the four fluorophores (l-phenylalanine; l-3,4-dihydroxyphenylalanine; 1,4-dihydroxybenzene and l-tryptophan) was conducted with excitation-emission data matrices. In the second experimental system, quantitation of ofloxacin was performed in water samples containing two other uncalibrated quinolones (ciprofloxacin and danofloxacin) by high performance liquid chromatography with UV-vis diode array detector. For comparison purpose, a GA algorithm coupled with N-PLS/RBL was also used in this work. In most of the studied cases iSPA-N-PLS proved to be a promising tool for selection of variables in second-order calibration, generating models with smaller RMSEP, when compared to both the global model using all of the sensors in two dimensions and GA-NPLS/RBL.

Eficácia "in vivo" da cefoperazona sódica, gentamicina e ciprofloxacino no tratamento intramamário da mastite clínica bovina / In vivo efficacy of sodium cefoperazone, gentamicin and ciprofloxacin for the intramammary treatment of clinical mastitis in cows / Eficacia in vivo de la cefoperazona sódica, la gentamicina y el ciprofloxacino en el tratamiento intramamario de la mastitis clínica bovina

O presente estudo avaliou a eficácia "in vivo" do tratamento intramamário, convencional e estendido, utilizando a cefoperazona sódica (250 mg), gentamicina (250 mg) e ciprofloxacino (100 mg) em casos de mastite clínica bovina. Foram utilizadas 30 vacas com mastite clínica, não sistêmica, distribuídas em três grupos de dez animais. O tratamento convencional da mastite consistiu em três aplicações do anti-mastítico, a cada 12 horas, e o tratamento estendido foi realizado com seis aplicações do anti-mastítico, a cada 12 horas. As vacas receberam tratamento intramamário, a cada 12 horas, com seis aplicações por animal, constituindo os seguintes momentos (M): M1 (dia zero - diagnóstico da mastite e início do tratamento), M2 (12 horas após M1), M3 (24 horas após M1), M4 (36 horas após M1), M5 (48 horas após M1) e M6 (60 horas após M1). Foi considerado, no mesmo animal, o tratamento convencional encerrado na terceira aplicação do antimicrobiano (M3) e o tratamento estendido ao final da sexta aplicação (M6). Os principais micro-organismos isolados das vacas com mastite foram Staphylococcus aureus, Staphylococus spp., Corynebacterium sp., Streptocccus spp., Streptococcus agalactiae e Escherichia coli. A cura clínica do tratamento convencional foi de 50% para o grupo tratado com cefoperazona sódica, 70% para o grupo tratado com gentamicina e 50% para o grupo tratado com ciprofloxacino. Para os mesmos grupos, a cura clínica do tratamento estendido foi 90%, 100% e 80%, respectivamente. A cura bacteriológica foi de 100% para o grupo tratado com cefoperazona sódica e de 90% para os grupos utilizando a gentamicina e ciprofloxacino no tratamento convencional. Para os mesmos grupos, foram observados 100% de cura bacteriológica para a gentamicina e 90% para os grupos com cefoperazona sódica e ciprofloxacino no tratamento estendido. Não foram encontradas diferenças entre cura clínica e cura bacteriológica dentro de cada grupo e entre os grupos de antimicrobianos, tampouco entre os tratamentos convencional e estendido dentro do mesmo grupo ou entre os grupos. Os resultados do presente estudo indicam a importância da lactocultura e do teste de sensibilidade microbiana "in vitro" como respaldo para os tratamentos intramamários de vacas com mastite clínica. Inferiu-se também a boa eficácia na cura clínica e bacteriológica da cefoperazona sódica, gentamicina e ciprofloxacino no tratamento da mastite clínica em vacas na lactação, de forma convencional ou estendida, contanto que respaldado na sensibilidade microbiana "in vitro".

This study evaluated the in vitro and in vivo efficacy of sodium cefoperazone, gentamicin and ciprofloxacin for the intramammary treatment of clinical mastitis in cows. Thirty cows with non-systemic, clinical mastitis were divided into three groups of ten animals. One of the antibiotics was used in each group for conventional (i.e., three doses, given every 12 hours) and extended (i.e., six doses, every 12 hours) treatments of mastitis. The cows were treated every 12 hours using six doses per animal at the next moments (M): M1, day zero ­ diagnosis and beginning of treatment; M2, 12 hours from diagnosis and treatment; M3, 24 hours; M4, 36 hours; M5, 48 hours; and M6 60 hours. The most common microorganisms isolated from cows were Staphylococcus aureus, Staphylococcus spp., Corynebacterium sp., Streptococcus spp., Streptococcus agalactiae and Escherichia coli. The efficacy of clinical cure using conventional treatment was 50%, 70% and 50% for the groups treated with sodium cefoperazone, gentamicin and ciprofloxacin, respectively. Regarding the extended treatment, efficacy was 90%, 100% and 80%, for sodium cefoperazone, gentamicin and ciprofloxacin, respectively. Efficacy of bacteriological cure was 100% for sodium cefoperazone, and 90% for both gentamicin and ciprofloxacin using the conventional treatment. By using the extended treatment, efficacy of bacteriological cure was 100% for gentamicin and 90% for both cefoperazone and ciprofloxacin. Statistical differences were not found in clinical or in bacteriological cure into the same group or among groups. Similarly, statistical differences between the conventional and extended treatments were not found. The results from this study reinforce the importance of performing microbiological culture of milk and in vitro antimicrobial sensitivity tests for supporting the intramammary treatment of clinical mastitis in cows. The clinical and bacteriological efficacy of sodium cefoperazone, gentamicin and ciprofloxacin in lactating cows suffering from clinical mastitis using either conventional or extended treatments was also inferred, provided the use of sensitivity tests in vitro.

El presente estudio comparó la eficacia in vitro e in vivo de la cefoperazona sódica, la gentamicina y el ciprofloxacino en el tratamiento intramamario de la mastitis clínica bovina. Fueron utilizadas 30 vacas con mastitis clínica sin signos sistémicos, divididas en tres grupos de diez animales. En cada grupo fue utilizado uno de los antibióticos citados antes, para realizar tratamiento convencional (tres aplicaciones a cada 12 horas) y extendido (seis aplicaciones a cada 12 horas) contra mastitis. Las vacas recibieron tratamiento intramamario a cada 12 horas, consistente de seis aplicaciones por animal en los siguientes momentos (M): M1, día cero - diagnóstico e inicio del tratamiento; M2, doce horas después del M1; M3, 24 horas después del M1; M4, 36 horas después del M1; M5, 48 horas después del M1; y M6 60 horas después del M1. Los principales microorganismos aislados de vacas con mastitis fueron Staphylococcus aureus, Staphylococcus spp., Corynebacterium sp. Streptococcus agalactiae spp. y Escherichia coli. La eficacia de la cura clínica usando tratamiento convencional fue de 50% para el grupo de cefoperazona sódica, 70% para gentamicina y 50% para ciprofloxacino. Con el tratamiento extendido la eficacia de la cura clínica fue de 90%, 100% y 80%, respectivamente. La eficacia de la cura bacteriológica fue de 100% para el grupo cefoperazona sódica y de 90% para los grupos gentamicina y ciprofloxacino utilizando el tratamiento convencional. Así mismo, se observó 100% de cura bacteriológica para gentamicina y 90% para los grupos cefoperazona sódica y ciprofloxacino utilizando el tratamiento extendido. No fueron observadas diferencias estadísticas para la cura clínica y bacteriológica ni dentro ni entre los grupos de antimicrobianos. Tampoco se encontró diferencia entre los tratamientos convencional y extendido dentro del mismo grupo o entre los grupos. Los resultados del presente estudio refuerzan la importancia del cultivo de la leche y de las pruebas de sensibilidad microbiana in vitro como respaldo para los tratamientos intramamarios en vacas con mastitis clínica. Los resultados permiten inferir también que la cefaperazona sódica, la gentamicina y el ciprofloxacino son eficaces para la cura clínica y bacteriológica de la mastitis clínica en vacas lactantes, tanto en un esquema de tratamiento convencional como en el tratamiento extendido siempre que se utilicen en combinación con exámenes de sensibilidad microbiana in vitro.

Green method based on a flow-batch analyzer system for the simultaneous determination of ciprofloxacin and dexamethasone in pharmaceuticals using a chemometric approach.

A green FBA method with UV detection was developed for simultaneous determination of ciprofloxacin (CIP) and dexamethasone (DEX) in ophthalmic and otic preparations. A lab-made mixing detection chamber (MDC) was designed and coupled to the spectrophotometer in order to perform the mixing of solutions and the detection in the same receptacle. Only water was used as solvent and no previous separation of the components was required. Both analytes have a strong absorption between 190 and 370 nm in aqueous medium, at pH 7. However, the spectrum of DEX is embedded in the CIP spectrum. Thus, while CIP was analyzed using univariate calibration, DEX analysis was carried out comparing partial least squares (PLS-1) and multiple linear regression (MLR). The latest required a previous variable selection step, which was performed using the genetic algorithm (GA) and the successive projections algorithm (SPA). The FBA system made it possible to automatically prepare the calibration and validation sets. The statistical parameters, in terms of relative errors of calibration and prediction, were acceptable for the determination of both CIP and DEX. Also, a comparative study of chemometric models was carried out. Commercial samples were analyzed and the obtained results are in close agreement with HPLC pharmacopeia methods. The joint interval test for the slope and the intercept was used to test for the presence of bias. There were no statistical differences between the proposed method and the reference method (α=0.05). The sample throughput was 10h(-1). The combination of automation and chemometric tools allows us to develop an environmental friendly method for the quality control of CIP and DEX in pharmaceuticals.

Molecular basis of high-level ciprofloxacin resistance in Neisseria gonorrhoeae strains from Shandong Province, China

In the study, the ciprofloxacin resistance rate was 100%. High-level ciprofloxacin resistance rate was 63.55%. Sixteen different mutation patterns involved in the formation of ciprofloxacin resistance were identified. The most prevalent were patterns P7 (25.2%), P8 (15.0%), P9 (11.2%), P1 (10.3%), and P5 (10.3%). All of the 107 NG isolates analyzed for mutations in the study have demonstrated a change of Ser-91 → Phe in the gyrA gene, and all except one have demonstrated a change in position 95 of the amino acid sequence. All of the 68 high-level QRNG isolates had double mutations in gyrA gene combined with a single or two mutations in parC gene. It is most important that a new mutation site of Ile-97 → Met in gyrA and a new mutation of Leu-106 → Ile in parC were found in the study, both leading to high-level ciprofloxacin resistance (MIC values, 8 µg/mL, 32 µg/mL, respectively). Therefore, we confim that gyrA mutations are necessary for the fluoroquinolone resistance phenotype and parC mutations are correlated intimately with high-level fluoroquinolone resistance. In China fluoroquinolone resistance in Neisseria gonorrhoeae strains is very serious and the new mutation sites in the fluoroquinolone resistance-determining regions emerge more and more quickly. Hence, in China fluoroquinolones, which are used to treat gonorrhoea presently, should be substituted by a new antibiotics.