ABSTRACT
Objective To establish a method for simultaneous determination of 3 tetracyline antibiotics (TCs) oxytetra-cycline (OTC), tetracycline (TC), chlorotetecycline (CTC)) residues in Zaosheng cattle meat using solid phase extraction-high performance liquid chromatography (SPE-HPLC). Methods The samples were extracted by Na2EDTA-Mcllvaine buffer solution (pH=4.0), and 15% trichloroacetic acid (TCA) as the protein precipitation solution, then the targets were cleaned up and enriched by C18 solid phase extraction column. HPLC Mobile phase consisted of oxalic acid (0.01mol/L), acetonitrile as well as methanol. The detection wavelength was 350 nm and external standard method was adopted for quantification. Results The calibration curves of 3 TCs had good linearity with correlation coefficients of 0.998. The limits of detection of OTC, TC and CTC were 18, 15, 30 μg/kg, respectively, while their average recoveries were 76.10%-95.22%, with relative standard deviations (RSD) lower than 10% after optimized pretreatment and analytical conditions. Conclusion The method has high sensitivity, precision, and good repeatability, and can meet the needs of residue determination of TCs in meat.
ABSTRACT
Herein we describe the preparation, characterization and utilization of chitosan nanoparticles for the intracellular delivery of the poorly cell-penetrating antibiotic e.g. Ciprofloxacin, Chlortetracycline hydrochloride and Gentamycin sulfate to improve their treatment of bacterial infections. Chitosan nanoparticles were prepared via the ionic gelation of chitosan with tri polyphosphate anions. Several parameters were studied to optimize the particle size of chitosan nanoparticles, here we select the concentration of chitosan and the concentrations of sodium tri poly phosphate (TPP) as optimizing parameters and the other factors stay constant such as pH of solution and ultrasonication time. Chitosan nanoparticles formed characterized by using FT-IR and transmission electron microscope (TEM). Results show that chitosan nanoparticles and its loaded antibiotics kill and inhibits the growth of gram (+) and gram (-) bacteria tested due to nanoparticles structures, and the antibacterial activity increased with increasing the anti biotic content.
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Aims: To study the effect of various doses of tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) on the enzymatic (DHA, acid phosphatase, alkaline phosphatase, urease and catalase) activity in sewage amended and un-amended alluvial soil. Methodology: A laboratory incubation study was conducted during 2012-2013 on an Aligarh farm alluvial soil. The enzymatic activity was studied in presence of various doses of three tetracycline antibiotics in soil; soil amended with sewage sludge; and mixture of sewage sludge and tetracyclines at different time intervals [(0 (4h), 7, 14, 21, 35, 56, 70,91d]. Results: Activity of all the studied enzymes was significantly inhibited for up to 14-21 days of incubation (14 d for DHA and acid phosphatase, 21 d for alkaline phosphatase, urease and catalase) and thereafter inhibition got weaker. The activity of all the studied enzymes decreased with increase in the doses of tetracyclines. Higher enzymatic activity was observed in sewage sludge amended soil than in the un-amended soil. Tetracyclines in presence of sewage sludge were found to have no appreciable effect on enzymatic activities. Conclusions: Dehydrogenase, acid and alkaline phosphatase, urease and catalase activity in tetracycline free soil was superior to soil containing antibiotics in the period of 2-3 weeks of incubation. The inhibition of soil enzyme activity was directly proportional to tetracycline concentration. In presence of sewage sludge, the studied enzymes activity initially increased up to 3 weeks and decreased thereafter. In presence of sewage sludge and antibiotics, the activity of enzymes remains almost unchanged. The activity of studied enzymes in soil was positively correlated to soil organic content.
ABSTRACT
An electrochemical sensor has been developed for the selective determination of chlortetracycline ( CTC) using the molecularly imprinted technique. A molecular imprinted polymer ( MIP) on the surface of a glassy carbon electrode ( GCE ) was prepared by electropolymerization of o-aminophenol ( OAP ) in the presence of CTC in the sodium perchlorate ( NaClO4 ) solution using cyclic voltammetry ( CV ) . The electrochemical performance of the sensor was studied by using differential pulse voltammetry ( DPV ) . A linear relationship between the peak current difference and the CTC concentration was found in the range of 2. 0×10-8-6. 1×10-7 mol/L with the detection limit of 1. 5×10-8 mol/L (3σ). After regeneration by washing with the mixture of methanol and sulfuric acid, the sensor showed excellent reproducibility and good stability. The MIP electrode exhibited almost no response to chloramphenicol and penicillin, and very weak responses to tetracycline and oxytetracycline, proving a good selectivity. Recoveries of standard addition measured in the actual samples of milk and chicken meat were between 86 . 4% -96 . 9%. Compared with the reported methods, this sensor showed a low detection limit, simple operation without derivatization, rapid response and low cost.
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The worldwide increase in the use of antibiotics as an integral part of poultry and livestock production industry has recently received increasing attention as a contributory factor in the international emergence of antibiotic-resistant bacteria in human beings. To gauge the presence of the aforementioned scenario in the Indian context, a preliminary survey was conducted to assess the use of chlortetracycline (CTC) in 12 commercial layer farms and to quantify and confirm its residue in the egg. Samples of feed and eggs were collected at day 0 (prior to CTC addition), 3rd, 5th and 7th day during treatment and on the 9th and 14th day (2nd and 7th day after withdrawal of CTC) from each of the 12 commercial poultry farms studied. Concentration of CTC in feed was significantly (P<0.01) high on the 3rd, 5th and 7th day. On the 9th day and 14th day CTC concentration in feed was significantly (P<0.01) lower compared to the earlier 3 days studied. A highly significant difference (P<0.01) of the antibiotic residue in egg was observed in all the 5 days with high residual levels of CTC in egg. CTC in feed and its residue in egg were detected even on the 9th and 14th day respectively.
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OBJECTIVE:To determine the contents of chlortetracycline hydrochloride and tetracaine hydrochloride in compound chlortetracycline hydrochloride ointment.METHODS:Dual wavelength spectrophotometry was used to determine the two components.The absorbance of the two components was determined at wavelength of 311 nm,368 nm and 387.5 nm,respectively;and the contents of which were computed as well.RESULTS:The linear ranges for chlortetracycline hydrochloride and tetracaine hydrochloride were 9.90～29.71 ?g?mL-1 and 5.99～17.98 ?g?mL-1(r=0.999 9),respectively,with average recovery rates at 99.37%(RSD=0.31%,n=9) and 98.31%(RSD=0.23%,n=9),respectively.CONCLUSION:The method is simple,rapid and accurate,and suitable for the determination of compound chlortetracycline hydrochloride ointment.
ABSTRACT
We have shown previously that the Ca2+-specific fluorescent dyes chlortetracycline (CTC) and indo-1/AM can be used to distinguish between prestalk and prespore cells in Dictyostelium discoideum at a very early stage. In the present study, pre- and post-aggregative amoebae of Dictyostelium discoideum were labelled with CTC or indo-1 and their fluorescence monitored after being drawn into a fine glass capillary. The cells rapidly form two zones of Ca2+-CTC or Ca2+-indo-1 fluorescence. Anterior (air side) cells display a high level of fluorescence; the level drops in the middle portion of the capillary and rises again to a lesser extent in the posteriormost cells (oil side). When bounded by air on both sides, the cells display high fluorescence at both ends. When oil is present at both ends of the capillary, there is little fluorescence except for small regions at the ends. These outcomes are evident within a couple of minutes of the start of the experiment and the fluorescence pattern intensifies over the course of time. By using the indicator neutral red, as well as with CTC and indo-1, we show that a band displaying strong fluorescence moves away from the anterior end before stabilizing at the anterior-posterior boundary. We discuss our findings in relation to the role of Ca2+ in cell-type differentiation in Dictyostelium discoideum.