Addition Of Oxytetracycline Research Articles

Simple and Selective Colorimetric Detection of Oxytetracycline Based on Fe(III) Ion-3,3’,5,5’-Tetramethylbenzidine

Oxytetracycline (OTC) is a common antibacterial agent used for the control of animal diseases. OTC abuse can seriously affect human health. Herein, based on the Fe(III)-3,3’,5,5’-tetramethylbenzidine (Fe(III)-TMB) system, a facile and rapid colorimetricassay for oxytetracycline (OTC) was successfully developed. The addition of OTC could remarkably enhance the Fe(III)-oxidized TMB reaction and the absorbance increase of Fe(III)-TMB solution is proportional to the added OTC. The linear range of proposed sensor for OTC was from 20 nM to 1000 nM with the detection limit of 7.97 nM. The high sensitivity for OTC detection was successfully achieved under optimal conditions. For real sample analysis, recoveries of 89.93% to 100.02% was obtained. This is the first report for detecting OTC based on the nonenzymatic colorimetric reaction using the intrinsic oxidized activity of OTC/Fe3+ complex. The present simple, low-cost and visualized sensor has great potential for OTC detection in food.

Oxytetracycline Toxicity and Its Effect on Phytoremediation by Sedum plumbizincicola and Medicago sativa in Metal-Contaminated Soil.

Excessive use of antibiotics potentially threatens human health, agricultural production, and soil phytoremediation. This arouses concern over the potential adverse effects of a commonly used antibiotic, oxytetracycline (OTC), on plants used for soil remediation and possible stimulation of antibiotic resistance genes in soils. A greenhouse experiment was conducted to investigate different rates (0, 1, 5, and 25 mg kg-1) and frequencies (one single high and daily low application) of OTC addition to soil on phytoremediation of a heavy metal contaminated soil by Sedum plumbizincicola and/or Medicago sativa (alfalfa). After 90 days both Cd and Zn were substantially removed by phytoextraction into S. plumbizincicola shoots especially at the high OTC (25 mg kg-1) treatment which also led to inhibition of antioxidative enzyme activities in both plant species. Soil microbial activity decreased significantly with the addition of OTC, and this was ameliorated by planting alfalfa and S. plumbizincicola together. OTC at <5 mg kg-1 increased the biomass of both plant species, but the frequency of OTC addition had no effect on the rate of metal removal. Alfalfa exhibited greater detoxification ability and effectiveness in soil microbial activity promotion than S. plumbizincicola with intercropping. Phytoremediation by alfalfa and S. plumbizincicola in association can both promote the removal of heavy metals and also alleviate the toxic effects of pollutants on plants and soil microbes even at relatively high soil OTC concentrations.

Determination of Oxytetracycline by a Graphene—Gold Nanoparticle-Based Colorimetric Aptamer Sensor

ABSTRACTA colorimetric aptamer sensor for the determination of oxytetracycline was developed based on the controllable peroxidase-like catalysis of a graphene/gold nanoparticle hybrid and the high affinity between oxytetracycline aptamers and oxytetracycline. The oxytetracycline aptamer was a single-stranded DNA sequence that was adsorbed on the interface of the hybrid, resulting in inhibition of the catalysis. The aptamer–oxytetracycline complex formed spontaneously following the addition of oxytetracycline, escaped from the hybrid, and recovered the catalytic ability that was inhibited by the aptamer. In the presence of hydrogen peroxide, the recovered hybrid oxidized a colorimetric reagent, causing a concomitant change in color. The whole process did not involve labeling and the color change was readily observed. This method provided a linear dynamic range for oxytetracycline from 0.17 to 0.50 µM with a detection limit of 91 nM and a quantification limit of 0.17 µM. In addition, the selectivity of the sensor was confirmed in the presence of high concentrations of potential interferents. This work is expected to encourage the development of additional simple and visible sensors for the determination of other pollutants.

Effects of oxytetracycline on archaeal community, and tetracycline resistance genes in anaerobic co-digestion of pig manure and wheat straw

ABSTRACTIn this study, the effects of different concentrations of oxytetracycline (OTC) on biogas production, archaeal community structure, and the levels of tetracycline resistance genes (TRGs) were investigated in the anaerobic co-digestion products of pig manure and wheat straw. PCR denaturing gradient gel electrophoresis analysis and real-time quantitative polymerase chain reaction (RT-qPCR) (PCR) were used to detect the archaeal community structure and the levels of four TRGs: tet(M), tet(Q), tet(W), and tet(C). The results showed that anaerobic co-digestion with OTC at concentrations of 60, 100, and 140 mg/kg (dry weight of pig manure) reduced the cumulative biogas production levels by 9.9%, 10.4%, and 14.1%, respectively, compared with that produced by the control, which lacked the antibiotic. The addition of OTC substantially modified the structure of the archaeal community. Two orders were identified by phylogenetic analysis, that is, Pseudomonadales and Methanomicrobiales, and the methanogen present during anaerobic co-digestion with OTC may have been resistant to OTC. The abundances of tet(Q) and tet(W) genes increased as the OTC concentration increased, whereas the abundances of tet(M) and tet(C) genes decreased as the OTC concentration increased.

Risk assessment of nitrate and oxytetracycline addition on coastal ecosystem functions

Diatoms dominate phytoplankton communities in the well-mixed coastal and upwelling regions. Coastal diatoms are often exposed to both aquaculture pollution and eutrophication. But how these exposures influence on coastal ecosystem functions are unknown. To examine these influences, a coastal centric diatom, Conticribra weissflogii was maintained at different concentrations of nitrate (N) and/or oxytetracycline (OTC). Algal density, cell growth cycle, protein, chlorophyll a, superoxide dismutase (SOD) activity, and malonaldehyde (MDA) were determined for the assessment of algal biomass, lifetime, nutritional value, photosynthesis and respiration, antioxidant capacity, and lipid peroxidation, respectively. When N addition was combined with OTC pollution, the cell growth cycles were shortened by 56–73%; algal density, SOD activities, the concentrations of chlorophyll a, protein, and MDA varied between 73 and 121%, 19 and 397%, 52 and 693%, 19 and 875%, and 66 and 2733% of the values observed in N addition experiments, respectively. According to P-value analysis, the influence of OTC on algal density and SOD activity was not significant, but the effect on cell growth cycle, protein, chlorophyll a, and MDA were significant (P<0.05). The influence of N addition with simultaneous OTC pollution on the above six end points was significant. Algal biomass, lifetime, nutrition, antioxidant capacity, lipid peroxidation, photosynthesis, and respiration were all affected by the addition of OTC and N. Coastal ecosystem functions were severely affected by N and OTC additions, and the influence was increased in the order: N<OTC<OTC+N. Thus, the simultaneous monitoring of N and OTC was necessary for the risk assessment of aquaculture pollution on coastal ecosystem functions.

Fluorescent assay for oxytetracycline based on a long-chain aptamer assembled onto reduced graphene oxide

We report on a fluorescent assay for oxytetracycline (OTC) using a fluorescein-labeled long-chain aptamer assembled onto reduced graphene oxide (rGO). The π-π stacking interaction between aptamer and rGO causes the fluorescence of the label to be almost completely quenched via energy transfer so that the system has very low background fluorescence. The addition of OTC leads to the formation of G-quadruplex OTC complexes and prevents the adsorption of labeled aptamer on the surface of rGO. As a result, fluorescence is restored, and this effect allows for a quantitative assay of OTC over the 0.1–2 μM concentration range and with a detection limit of 10 nM. This method is simple, rapid, selective and sensitive. It may be applied to other small molecule analytes by applying appropriate aptamers.

Risk assessment of oxytetracycline in water phase to major sediment bacterial community: A water-sediment microcosm study

With an increasing need for assessing the risk of aquaculture antibiotics, there has been growing interest in their fate and effect on sedimentary bacteria. Here we show the risk assessment for oxytetracycline (OTC) use in seawater and its subsequent transfer to sediment, and illustrate that the sediment bacterial community was stable against OTC at dosed concentrations. Water-sediment microcosm experiments were conducted to simulate quiescent aquaculture conditions. The sorption coefficient (Kd) was 12.3–44.2mL/g, which is lower than the previous reports employing vigorous mixing. In a denaturing gradient gel electrophoresis (DGGE) analysis, the addition of OTC at 50μg/L into the water phase had little effect on the major sediment bacterial community structure. This finding suggests that low concentrations of OTC in the water phase – such as those used within many aquaculture operations – do not pose a high risk of causing major changes in environmental sediment bacterial community structures.

土霉素对堆肥过程中酶活性和微生物群落代谢的影响

以猪粪和秸秆为试验材料，研究了土霉素对堆肥温度、种子发芽指数、C/N、纤维素酶、脲酶、过氧化氢酶以及微生物群落代谢的影响。结果表明，0 mg/kg（对照处理）的堆肥在第2天上升到 50 ℃以上，维持了 5 d，达到了无害化处理的要求。35 mg/kg土霉素处理（A1 处理）第4天升到 51.0 ℃，其高温期维持了 1 d。70 mg/kg 土霉素处理（A2 处理）第3天升到 50 ℃以上，高温期维持了 2 d。105 mg/kg 土霉素处理（A3 处理）和 140 mg/kg 土霉素处理（A4 处理）的温度在整个堆肥期间均未达到 50 ℃。在堆肥结束时各个处理的种子发芽指数均达到 80% 以上。CK（对照处理）、A1、A2、A3 和 A4 处理的 C/N 由 34.50 分别降为 16.64、16.07、19.48、18.45 和 19.83。堆肥的第1天，A1、A2、A3 和 A4 处理对纤维素酶活性的抑制率分别为 60.30%、21.30%、48.81% 和 76.05%，第3天，土霉素对纤维素酶活性起促进作用，在 4-30 d，A3、A4 处理对纤维素酶活性有抑制作用。在堆肥的前期（1-3 d），土霉素刺激脲酶活性，随着堆肥时间的延长，土霉素对脲酶活性由刺激变为抑制作用，在第18-30天 A3、A4 处理与 CK 相比有着显著的抑制作用。在堆肥第1天到第18天，土霉素基本上促进过氧化氢酶的活性，堆肥 18 d 之后土霉素对过氧化氢酶起着是抑制作用。用 Biolog（ECO Microplate）方法研究了土霉素对堆肥过程中微生物群落代谢的影响，结果表明，在升温期 CK 处理的平均颜色变化率AWCD（Average Well Color Development）在培养 60 h 之后大于其他处理，高温期 A2 处理的 AWCD 值最高，在降温期 CK 的 AWCD 值一直是最高的。对 Shannon 指数进行分析显示，堆肥的初始阶段土霉素降低微生物群落的功能多样性，随着时间的延长，土霉素增加微生物群落的功能多样性。对微生物利用六大类碳源分析表明，140 mg/kg 的土霉素浓度能够改变微生物利用碳源的种类。;An outdoor experiment was conducted to study the effect of oxytetraeyeline addition on composting temperature, seed germination index, ratio of carbon to nitrogen, cellulose, urease, catalase and microbial community metabolism during composting of pig manure mixed with wheat straw. The results showed that composting temperature was reached to 50 ℃ in the second day of composting and lasted for 5 days on treatment without addition of oxytetraeyeline (Control check,CK), which could meet the need of the requirement of harmlessness. The composting temperature was above 51.0 ℃ in the fourth day of composting with addition of 35 mg/kg oxytetracycline (A1 treatment), and the high temperature period maintained for 1 day. The temperature was above 50 ℃ in the third day of composting where 70 mg/kg oxytetracycline was added (A2 treatment), and the high temperature period only hold on for 2 days. The temperature could not reach to 50 ℃ over the whole time of composting on both A3 and A4 treatments where 105 mg/kg and 140 mg/kg of oxytetracycline were spiked respectively. The germination indices (<em>GI</em>) of seeds, which contained in the compost materials, were higher than 80% for all treatments at the end of the composting. The C/N ratios for all treatments were decreased from an initial value of 34.50 to 16.64, 16.07, 19.48, 18.45 and 19.83, respectively, when composting completed. Activities of cellulose on treatments those receiving oxytetracycline were inhibited by 60.30%, 21.30%, 48.81% and 76.05%, respectively, over CK treatment in the first day of the composting, and they were increased in the third day. Nevertheless, activities of cellulase were inhibited under A3 and A4 treatments compared with CK from day 4 to day 30. The activity of urease was increased by addition of oxytetracycline in the first 3 days, since then on, it was decreased. The higher concentrations of oxytetracycline (A3 and A4) had a significant inhibitory effect on activity of urease from day 18 to day 30. The catalase activity was enhanced generally by the addition of oxytetraeyeline from day 1 to day 18 compared to CK, from then on it was decreased over CK. The effect of oxytetracycline addition on microbial community metabolic profiles during composting was assayed with Biolog (ECO Microplate) method. The results showed that AWCD (Average Well Color Development) values of CK treatment were the highest after 60 h incubation during temperature raising period of the compost. The highest AWCD values were observed on A2 treatment during the high temperature period. AWCD values under CK were greater than other treatments over cooling period. Shannon index results suggested that the oxytetracycline addition could reduce the functional diversity of microbial communities in the initial stage of the composting, in contrast, it could increase the functional diversity of microbial communities at other stages of composting. The carbon source utilization data showed that the addition of 140 mg/kg of oxytetracycline could significantly change the types of carbon sources used by microorganisms.

Wheat Growth and Photosynthesis as Affected by Oxytetracycline as a Soil Contaminant

Extensive worldwide use of oxytetracycline (OTC), a member of the tetracyclines, has resulted in its accumulation in soils, posing a potential risk to food production and safety. A pair of OTC-sensitive (Heyou 1) and OTC-tolerant (Yannong 21) wheat ( Triticum aestivum L.) cultivars was compared hydroponically at 0.01, 0.02, 0.04, and 0.08 mmol L −1 OTC in terms of wheat growth and photosynthesis. Biomass and shoot length decreased significantly with the addition of OTC, with the decreases in dry biomass and shoot length being 5.61%-13.75% and 3.33%-8.57% larger, respectively, for Heyou 1 than Yannong 21. Photosynthesis of Heyou 1 was suppressed by OTC as indicated by the significant decreases in photosynthetic rate (PN), transpiration rate (TR), and stomatal conductance (GS) and the significant increase in intercellular CO 2 concentrations (CI), at all OTC levels. Stomatal limitation (LS) and water use efficiencies (WUE) of Heyou 1 also increased significantly, but not at 0.08 mmol L −1 OTC. However, photosynthesis of Yannong 21 was suppressed by OTC only at high OTC levels from 0.02 to 0.08 mmol L −1 as indicated by the decreases in PN, GS, TR, and LS; at 0.01 mmol L −1 OTC, PN, CI, GS, and TR significantly increased. It was noted that WUE of Yannong 21 was not affected by OTC addition. The results from this hydroponic test suggested that OTC had a potential risk to crop growth through inhibition of photosynthesis, requiring further confirmation with soil tests.

Intracellular infection by the human granulocytic ehrlichiosis agent inhibits human neutrophil apoptosis.

In patients with human granulocytic ehrlichiosis (HGE), the HGE agent has been seen only in the peripheral blood granulocytes, which have a life span too short for ehrlichial proliferation. To determine if the HGE agent delays the apoptosis of human peripheral blood neutrophils for its advantage, peripheral blood granulocytes consisting mostly of neutrophils were incubated with freshly freed host cell-free HGE agent in vitro. The HGE agent induced a significant delay in morphological apoptosis and the cytoplasmic appearance of histone-associated DNA fragments in the granulocytes. This antiapoptotic effect was dose dependent. Although much weaker than the HGE agent freshly freed from the host cells, noninfectious purified HGE agent stored frozen and thawed also had antiapoptotic effect, which was lost with proteinase K treatment but not with periodate treatment. Treatment of neutrophils with a transglutaminase inhibitor, monodansylcadaverine, blocked the antiapoptotic effect of the HGE agent. Addition of oxytetracycline, however, did not prevent or reverse the antiapoptotic effect of the HGE agent. These results suggest that binding of a protein component(s) of the HGE agent to neutrophils and subsequent cross-linking and/or internalization of the receptor and ehrlichiae are required for antiapoptotic signaling, but ehrlichial protein synthesis and/or proliferation is not required. MG-132, a proteasome inhibitor, and cycloheximide accelerated the apoptosis of neutrophils and overrode the antiapoptotic effect of the HGE agent. Studies with specific inhibitors suggest that protein kinase A, NF-kappaB, and interleukin 1beta are not involved in the antiapoptotic mechanism of the HGE agent.

Ehrlichia chaffeensis and E. sennetsu, but not the human granulocytic ehrlichiosis agent, colocalize with transferrin receptor and up-regulate transferrin receptor mRNA by activating iron-responsive protein 1.

Ehrlichia chaffeensis and E. sennetsu are genetically divergent obligatory intracellular bacteria of human monocytes and macrophages, and the human granulocytic ehrlichiosis (HGE) agent is an obligatory intracellular bacterium of granulocytes. Infection with both E. chaffeensis and E. sennetsu, but not HGE agent, in the acute monocytic leukemia cell line THP-1 almost completely inhibited by treatment with deferoxamine, a cell-permeable iron chelator. Transferrin receptors (TfRs) accumulated on both E. chaffeensis and E. sennetsu, but not HGE agent, inclusions in THP-1 cells or the cells of the promyelocytic leukemia cell line HL-60. Reverse transcription-PCR showed an increase in the level of TfR mRNA 6 h postinfection which peaked at 24 h postinfection with both E. chaffeensis and E. sennetsu infection in THP-1 or HL-60 cells. In contrast, HGE agent in THP-1 or HL-60 cells induced no increase in TfR mRNA levels. Heat treatment of E. chaffeensis or the addition of monodansylcadaverine, a transglutaminase inhibitor, 3 h prior to infection inhibited the up-regulation of TfR mRNA. The addition of oxytetracycline 6 h after E. chaffeensis infection caused a decrease in TfR mRNA which returned to the basal level by 24 h postinfection. These results indicate that both internalization and continuous proliferation of ehrlichial organisms or the production of ehrlichial proteins are required for the up-regulation of TfR mRNA. Results of electrophoretic mobility shift assays showed that both E. chaffeensis and E. sennetsu infection increased the binding activity of iron-responsive protein 1 (IRP-1) to the iron-responsive element at 6 h postinfection and remained elevated at 24 h postinfection. However, HGE agent infection had no effect on IRP-1 binding activity. This result suggests that activation of IRP-1 and subsequent stabilization of TfR mRNA comprise the mechanism of TfR mRNA up-regulation by E. chaffeensis and E. sennetsu infection.

Feed intake and growth of Arctic charr, Salvelinus alpinus (L.), fed diets supplemented with oxytetracycline and squid extract

This study examined the long-term effects of a potential feeding deterrent, oxytetracycline (OTC), and a putative feeding stimulant, squid extract, on feed intake, growth and dry matter (DM) digestibility in Arctic charr, Salvelinus alpinus (L.). Fish were fed one of four diets for 9 weeks: 1. commercial feed formulation (basic); 2. BM (basic plus 20 g kg−1 OTC); 3. BMS (BM plus 10 g kg−1 squid extract); 4. BS (basic plus 10 g kg−1 squid extract). The feed intake of Arctic charr was not reduced by the addition of OTC to the basic feed, and addition of squid extract to the medicated feed did not enhance feed consumption. DM digestibility and growth tended to be reduced in groups of fish fed diets supplemented with the antibiotic (BM and BMS). This suggests that OTC may have interfered with nutrient digestion and absorption. OTC does not seem to be a feeding deterrent for Arctic charr, possibly indicating that the charr is a rather unselective feeder. Because the medicated feeds were readily accepted, there may be little to be gained by addition of feeding stimulants to these types of feeds for charr.

Does oral administration of oxolinic acid or oxytetracycline affect feed intake of rainbow trout?

Short-term oral drug intake was measured in rainbow trout ( Oncorhynchus mykiss) using radioactively labelled diets. In Experiment 1, duplicate groups of trout were fed either a control diet without antibiotic addition, or diets containing either 10 g oxolinic acid (OA) or 10 g oxytetracycline (OTC) per kg. In Experiment 2, triplicate groups of trout were fed diets containing either 1 or 10 g OA per kg. The trout, weighing 200–900 g, were kept in freshwater at 10°C. The fish were accustomed to feeding to satiation every 20 min, 20 h/day; the drugs were fed over a 6-h period. The amount of radioactive feed ingested by the fish was measured directly on anaestherized fish with a portable gamma scintillation counter. The results showed that OA in the diet tended to reduce mean feed intake (mean reduction 17%) compared to controls. This reduction was, however, not significant ( P=0.09). Addition of OTC led to a 61% reduction in feed intake ( P<0.05).

MECHANISM OF THE RESISTANCE OF STAPHYLOCOCCUS AUREUS TO TETRACYCLINES

A strain of Staphylococcus aureus resistant to oxytetracycline and cross-resistant to tetracycline was isolated and the mechanism of its resistance to the drug was studied.1. The incorporation of amino acids-U-14C into the protein fraction decreased in the sensitive cells upon addition of oxytetracycline (10μg/ml), while no remarkable influence was observed in the resistant cells. On the other hand, the incorporations of amino acids-U-14C into the protein fraction with the cell-free extracts from the sensitive as well as the resistant cells were equally inhibited by tetracycline.2. The uptake of radioactive tetracycline by the sensitive cells was much higher than that by the resistant cells. In order to investigate the mechanism of the decrease in the permeability of the cells to the drug, the intracellular concentration of tetracycline was estimated from the uptake of the drug and its inhibitory effect on the protein biosynthesis in the intact cells. Permeability of the resistant cells to the drug was found to decrease to about 1/100 of that of the sensitive ones and a large part of the drug taken up by the resistant cells seemed to be non-specifically bound to the cellular surface.3. At low concentrations of tetracycline, its uptake by the sensitive cells was decreased by lowering the temperature or by the addition of energy poisons such as azide, while the uptake by the resistant ones was not much affected. At high concentrations of tetracycline, on the other hand, its uptake by the resistant cells was inhibited by azide as in the sensitive cells.

Tetracycline inhibition of changes in the redox potential during the logarithmic phase of growth of sensitive microorganisms.

The addition of Oxytetracycline to an aerated broth culture of the sensitive strainsStaphylococcus Oxford andEscherichia coli 514 during the logarithmic phase of growth immediately stopped the usual steady drop in redox potential values. No differences were found in the dynamics of rH changes during growth of resistant variants of these strains.

Topical hydrocortisone-oxytetracycline therapy.

The advent of topical hydrocortisone therapy * during the past year made inevitable the combined use of hydrocortisone with other topical agents. This paper represents an attempt at objective evaluation of an ointment containing 1% hydrocortisone and 3% oxytetracycline (Terramycin) in a petrolatum base. We tried to answer the following questions: Is the addition of oxytetracycline to hydrocortisone necessary? Does hydrocortisone interfere with the cutaneous defense against bacterial invasion? Does hydrocortisone interfere with, augment, or in any other way alter the action of oxytetracycline upon the skin? Does oxytetracycline interfere with, augment, or in any way alter the action of hydrocortisone upon the skin? What valid criteria do we have for diagnosing secondary cutaneous infection as against mere colonization of bacteria? PLAN OF INVESTIGATION When one deals with such a compound, theoretically the following controls are possible: Hydrocortisone-oxytetracycline