A simple sample treatment for the determination of enrofloxacin and ciprofloxacin in raw goat milk

Evaluating the efficacy of an algae-based treatment to mitigate elicitation of antibiotic resistance

Antibiotics in the effluents of municipal wastewater treatment plants (WWTP) may create selective pressures to induce antibiotic resistance in bacteria downstream. This study evaluates ciprofloxacin (CIP) removal by a freshwater alga, Scenedesmus dimorphus, to assess the efficacy of algae-based tertiary treatment in reducing effluent-induced CIP resistance. Results show significant CIP removal in light-exposed samples without algae and experimental algae (EA) samples: 53% and 93%, respectively, over 144 h. A residual antibiotic potency assay reveals that untreated CIP is significantly more growth-inhibiting to a model bacterium (Escherichia coli) than the algae-treated and light-exposed samples during short exposures (6 h). Adaptive laboratory evolution (ALE), again using E. coli, reveals that treated samples exhibit reduced capacity to elicit CIP resistance during sustained exposures compared to untreated CIP. Finally, observed CIP resistance in the CIP-exposed ALE lineages is corroborated via genotype characterization, which reveals the presence of resistance-associated mutations in gyrase subunit A (gyrA) that are not present in ALE lineages exposed to algae treated or light-exposed samples. As such, algae-mediated tertiary treatment could be effective in suppressing CIP resistance in bacterial communities downstream from WWTP. In addition, ALE is useful for assessing the potential of wastewater-relevant samples to elicit antibiotic resistance downstream.

New and miniaturized method for analysis of enrofloxacin in palatable tablets

Enrofloxacin is an antimicrobial for oral use, from the fluoroquinolones of second-generation class, and it is the first fluoroquinolone used in veterinary for the treatment of bacterial infections. The development of trustworthy analytical methods has extreme importance for the assurance of safety, quality and therapeutic efficiency of pharmaceuticals. Previous articles in the literature describe several analytical methods for evaluation of enrofloxacin, but they do not use spectrophotometry in the visible region, nor use a miniaturized method or ecologically correct. In this work an analytical method for quantification of enrofloxacin in palatable tablets for veterinary prescriptions was developed and validated by spectrophotometry in the visible region. This method used a spectrophotometer UV-Vis BMG LabTechSpectrostar Nano, solution of iron chloride 0.5% as complexing agent, microplates and the analyses were conducted at 430 nm. The validation was conducted following international guides and showed linearity between the concentrations of 100 and 200 μg/ mL, selectivity, precision (intraday RSD 0.52%, interday RSD 0.44% and interanalyst RSD 0.56%), accuracy of 98.51% and robustness to time of analysis variation and wavelength. Therefore, the developed method approached the required parameters of validation and can be considered suitable for quantification of enrofloxacin in palatable tablets. The method also involves characteristics in green analytical chemistry for the current pharmaceutical analysis. This work contemplates a miniaturized, clean, innovator, fast and low cost method by spectrophotometry in the visible region for quantification of enrofloxacin in palatable tablets.

Evaluation of Antibacterial Enrofloxacin in Eggs by Matrix Solid Phase Dispersion-Flow Injection Chemiluminescence

The study based on the chemiluminescence (CL) reaction of potassium ferricyanide and luminol in sodium hydroxide medium, enrofloxacin (ENRO) could dramatically enhance CL intensities and incorporated with matrix solid-phase dispersion (MSPD) technique (Florisil used as dispersant, dichloromethane eluted the target compounds). A simple flow injection chemiluminescence (FL-CL) method with MSPD technique for determination of ENRO in eggs was described. Under optimal conditions, the CL intensities were linearly related to ENRO concentration ranging from4.0×10-8 g.L−1to5.0×10-5 g.L−1, with a correlation coefficient of 0.9989 and detection limit of5.0×10-9 g.L−1. The relative standard deviation was 3.6% at an ENRO concentration of2.0×10-6 g.L−1. Our testing technique can help ensure food safety, and thus, protect public health.