The degradation of tilmicosin(TLM),a semi-synthetic 16-membered macrolide antibiotic,has been receiving increasing attention.Conventionally,there are three tilmicosin degradation methods,and among them microbial degra...The degradation of tilmicosin(TLM),a semi-synthetic 16-membered macrolide antibiotic,has been receiving increasing attention.Conventionally,there are three tilmicosin degradation methods,and among them microbial degradation is considered the best due to its high efficiency,eco-friendliness,and low cost.Coincidently,we found a new strain,Glutamicibacter nicotianae sp.AT6,capable of degrading high-concentration TLM at 100 mg/L with a 97%removal efficiency.The role of tryptone was as well investigated,and the results revealed that the loading of tryptone had a significant influence on TLM removals.The toxicity assessment indicated that strain AT6 could efficiently convert TLM into less-toxic substances.Based on the identified intermediates,the degradation of TLM by AT6 processing through two distinct pathways was then proposed.展开更多
Tilmicosin was administered intravenously and subcutaneously at a dose rate of 10 mg/kg bwt to determine its concentration in blood and bronchial secretion as well as its kinetic behavior in healthy and Pasteurella ha...Tilmicosin was administered intravenously and subcutaneously at a dose rate of 10 mg/kg bwt to determine its concentration in blood and bronchial secretion as well as its kinetic behavior in healthy and Pasteurella haemolytica type A1-infected calves. Sever acute bronchopneumonia was induced in 10 calves by inoculating them intra-tracheally with P. haemolytica type A1. The calves were treated with tilmicosin;5 of these received the drug intravenously and the other 5 were injected subcutaneously. After a slow intravenous injection, the serum concentration-time curve indicated a two compartment open model with a mean elimination half-lives (t1/2bs) of 22.09 and 22.14 hours before and after infection, respectively. The mean residence time (MRT) corrected for a bolus injection was 2.25 and 2.20 hours and the mean MRTinf was 25.27 and 25.46 hours in healthy and P. haemolytica-infected calves, respectively. After subcutaneous injection, the drug was eliminated more slowly (before and after infection) from serum and bronchial secretions, with t1/2bs of (24.60 and 25.85 hours) and (33.74 and 31.78 hours), respectively. The apparent volume of distribution (Vd(area)) of tilmicosin was more than 1 litre·kg-1. The peak serum and bronchial secretions of tilmicosin concentration were (1.33 and 1.36 mg·ml-1) and (1.40 and 1.70 mg·ml-1) attained at (7.21 and 7.15 hours) and 7.11 and 7.10 hours) after subcutaneous injection, respectively. Tilmicosin was good secreted into bronchial secretions having AUCbronchial secretion/ AUCserum ratio of approximately 1:1.24 and 1:1.22 in healthy and P. haemolytica-展开更多
The effect of tilmicosin on fetal development in pregnant female rats was investigated in this study. Forty pregnant female rats were divided into four groups (each of 10 female rats). Rats in the 1st, 2nd and 3rd gro...The effect of tilmicosin on fetal development in pregnant female rats was investigated in this study. Forty pregnant female rats were divided into four groups (each of 10 female rats). Rats in the 1st, 2nd and 3rd groups were received tilmicosin at a dose of 20, 100, 200 mg/kg·b·wt/day orally from the 6th to 15th day of gestation respectively, while the 4th group received 0.5 ml distilled water orally for the same period of gestation and was used as control group. All the pregnant female rats were sacrificed on the 20th day of gestation and their fetuses were subjected to morphological, visceral and skeletal examinations. Tilmicosin at a dose 100, 200 mg/kg·b·wt significantly decreased the number of viable fetuses;the number of resorbed fetuses was increased, and induced retardation in growth of viable fetuses;some skeletal and visceral defects in these fetuses were observed and these effects were dose dependant. It could be concluded that tilmicosin caused some abnormalities and fetal defects, so it is recommended to avoid using pregnancy.展开更多
To reduce the false positive results caused by cross reactivity of the antibodies with other structural analogues,it is crucial to prepare a high specificity and sensitivity antibody against target for developing an a...To reduce the false positive results caused by cross reactivity of the antibodies with other structural analogues,it is crucial to prepare a high specificity and sensitivity antibody against target for developing an accurate immunoassay.In this study,tilmicosin(TM)was selected as a model molecule.Firstly,two-dimensional similarity,electrostatic potential energy,mulliken atomic charges and overlapping of different haptens with TM were calculated using Gaussian 09W and Discovery studio,and the newly designed TM-HS was selected as the optimal hapten.Furthermore,a monoclonal antibody(mAb 12C8)was produced with the half maximal inhibitory concentration(IC50)of 0.36 ng/mL,and negligible cross-reactivity(CR)with other antibiotics.Finally,a lateral flow immunoassay(LFA)for the detection of TM based on amorphous carbon nanoparticles(ACNPs)labeled mAb 12C8 was developed by the reflectance value under natural light.The recoveries of TM ranged from 83.18%to 103.25%with a coefficient of variation(CV)<12.47%.The results showed that the cut-off value of TM in milk samples was 1 ng/mL,and the limits of detection(LODs)for chicken muscle,bovine muscle,porcine muscle and porcine liver samples were 5.23,5.98,6.85 and 7.31μg/kg,respectively.In addition,40 real samples were tested by the LFA,and the detection results were consisted with that of high-performance liquid chromatography-UV detector(HPLC-UV).Those results indicated that the developed LFA is an accurate and useful tool for on-site screening of TM in milk and animal tissues.展开更多
To quantitatively determine tylosin and tilmicosin in edible animal tissues,a time-resolved fluoroimmunoassay(TRFIA) has been developed and validated.For this purpose,desmycosin-O-carboxymethoxylamine-BSA was fixed on...To quantitatively determine tylosin and tilmicosin in edible animal tissues,a time-resolved fluoroimmunoassay(TRFIA) has been developed and validated.For this purpose,desmycosin-O-carboxymethoxylamine-BSA was fixed onto microtiter plates,standards and samples were loaded and,finally,diluted europium-labeled anti-tylosin antibodies were added.Results show that the limit of detection for tylosin was 0.03 ng mL-1 and that for tilmicosin was 0.05 ng mL-1.The recoveries were 73.6% to 120.5%,with coefficients of variation below 15.6% in various biological matrices spiked with tylosin and tilmicosin at concentrations of 50-200 ngg-1.There was good correlation(R2>0.99) between the TRFIA,an enzyme-linked immunosorbent assay and high performance liquid chromatography data.In conclusion,the new TRFIA is applicable to the detection of tylosin and tilmicosin and is an effective and economical method that will enable high-throughput sample screening.The method is expected to be widely applicable.展开更多
试验旨在建立一种同时测定牛奶中替米考星(tilmicosin)、地塞米松(dexamethasone)、氟苯尼考(florfenicol)和氯霉素(chloramphenicol)的超高效液相色谱-串联质谱(ultra performance liquid chromatography-tandem mass spectrometry,UPL...试验旨在建立一种同时测定牛奶中替米考星(tilmicosin)、地塞米松(dexamethasone)、氟苯尼考(florfenicol)和氯霉素(chloramphenicol)的超高效液相色谱-串联质谱(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)法。牛奶样品经乙腈提取后,将提取液通过Oasis PRiME HLB固相萃取小柱净化,净化后的样液经氮吹浓缩后,用样品稀释液溶解并用正己烷进一步除去脂肪获得待分析样品,进行UPLCMS/MS分析。采用CAPCELL PAK C18MGIII-H色谱柱(2mm×100mm,3μm)进行液相色谱分离,以甲醇(A)-含0.01%甲酸的0.1mmol/L甲酸铵溶液(B)为流动相进行梯度洗脱:0~1.0min,90%至60%B;1.0~3.0min,60%至30%B;3.0~4.4min,30%至20%B;4.4~4.5min,20%~90%B;4.5~6.0min,90%B。在多反应监测(multiple reaction monitoring,MRM)模式下进行质谱测定,以基质匹配标准溶液外标法定量。结果显示,替米考星、地塞米松、氟苯尼考和氯霉素在1.0~100.0μg/L范围内均具有良好的线性关系(r>0.999)。方法的最低检测限(limits of detection,LODs)为0.1~0.2μg/kg,定量限(limits of quantity,LOQs)为0.2~0.5μg/kg,当4种化合物在牛奶中的添加水平为0.5、5.0和25.0μg/kg时,回收率为78.6%~94.7%,相对标准偏差(relative standard deviations,RSDs)为2.4%~10.1%。本试验建立的UPLC-MS/MS方法简便、灵敏、准确,适用于牛奶中替米考星、地塞米松、氟苯尼考和氯霉素的同时测定。展开更多
基金supported by the National Natural Science Foundation of China(Nos.21868011,42106144,42077444)the National Key R&D Program of China(No.2017YFC1103800)the financial support from Shandong University of Science and Technology(No.SKR19-1-012)。
文摘The degradation of tilmicosin(TLM),a semi-synthetic 16-membered macrolide antibiotic,has been receiving increasing attention.Conventionally,there are three tilmicosin degradation methods,and among them microbial degradation is considered the best due to its high efficiency,eco-friendliness,and low cost.Coincidently,we found a new strain,Glutamicibacter nicotianae sp.AT6,capable of degrading high-concentration TLM at 100 mg/L with a 97%removal efficiency.The role of tryptone was as well investigated,and the results revealed that the loading of tryptone had a significant influence on TLM removals.The toxicity assessment indicated that strain AT6 could efficiently convert TLM into less-toxic substances.Based on the identified intermediates,the degradation of TLM by AT6 processing through two distinct pathways was then proposed.
文摘Tilmicosin was administered intravenously and subcutaneously at a dose rate of 10 mg/kg bwt to determine its concentration in blood and bronchial secretion as well as its kinetic behavior in healthy and Pasteurella haemolytica type A1-infected calves. Sever acute bronchopneumonia was induced in 10 calves by inoculating them intra-tracheally with P. haemolytica type A1. The calves were treated with tilmicosin;5 of these received the drug intravenously and the other 5 were injected subcutaneously. After a slow intravenous injection, the serum concentration-time curve indicated a two compartment open model with a mean elimination half-lives (t1/2bs) of 22.09 and 22.14 hours before and after infection, respectively. The mean residence time (MRT) corrected for a bolus injection was 2.25 and 2.20 hours and the mean MRTinf was 25.27 and 25.46 hours in healthy and P. haemolytica-infected calves, respectively. After subcutaneous injection, the drug was eliminated more slowly (before and after infection) from serum and bronchial secretions, with t1/2bs of (24.60 and 25.85 hours) and (33.74 and 31.78 hours), respectively. The apparent volume of distribution (Vd(area)) of tilmicosin was more than 1 litre·kg-1. The peak serum and bronchial secretions of tilmicosin concentration were (1.33 and 1.36 mg·ml-1) and (1.40 and 1.70 mg·ml-1) attained at (7.21 and 7.15 hours) and 7.11 and 7.10 hours) after subcutaneous injection, respectively. Tilmicosin was good secreted into bronchial secretions having AUCbronchial secretion/ AUCserum ratio of approximately 1:1.24 and 1:1.22 in healthy and P. haemolytica-
文摘The effect of tilmicosin on fetal development in pregnant female rats was investigated in this study. Forty pregnant female rats were divided into four groups (each of 10 female rats). Rats in the 1st, 2nd and 3rd groups were received tilmicosin at a dose of 20, 100, 200 mg/kg·b·wt/day orally from the 6th to 15th day of gestation respectively, while the 4th group received 0.5 ml distilled water orally for the same period of gestation and was used as control group. All the pregnant female rats were sacrificed on the 20th day of gestation and their fetuses were subjected to morphological, visceral and skeletal examinations. Tilmicosin at a dose 100, 200 mg/kg·b·wt significantly decreased the number of viable fetuses;the number of resorbed fetuses was increased, and induced retardation in growth of viable fetuses;some skeletal and visceral defects in these fetuses were observed and these effects were dose dependant. It could be concluded that tilmicosin caused some abnormalities and fetal defects, so it is recommended to avoid using pregnancy.
基金supported by the Key Scientific and Technological Project of Henan Provincial Department of China(222102310162)the National Natural Science Foundation of China(32172298)+2 种基金the Young Talents Project of Henan Agricultural University(30501305)the Henan Postgraduate Joint Training Base Project(YJS2022JD16)the Program for Innovative Research Team(in Science and Technology),University of Henan Province(NO.23IRTSTHN023).
文摘To reduce the false positive results caused by cross reactivity of the antibodies with other structural analogues,it is crucial to prepare a high specificity and sensitivity antibody against target for developing an accurate immunoassay.In this study,tilmicosin(TM)was selected as a model molecule.Firstly,two-dimensional similarity,electrostatic potential energy,mulliken atomic charges and overlapping of different haptens with TM were calculated using Gaussian 09W and Discovery studio,and the newly designed TM-HS was selected as the optimal hapten.Furthermore,a monoclonal antibody(mAb 12C8)was produced with the half maximal inhibitory concentration(IC50)of 0.36 ng/mL,and negligible cross-reactivity(CR)with other antibiotics.Finally,a lateral flow immunoassay(LFA)for the detection of TM based on amorphous carbon nanoparticles(ACNPs)labeled mAb 12C8 was developed by the reflectance value under natural light.The recoveries of TM ranged from 83.18%to 103.25%with a coefficient of variation(CV)<12.47%.The results showed that the cut-off value of TM in milk samples was 1 ng/mL,and the limits of detection(LODs)for chicken muscle,bovine muscle,porcine muscle and porcine liver samples were 5.23,5.98,6.85 and 7.31μg/kg,respectively.In addition,40 real samples were tested by the LFA,and the detection results were consisted with that of high-performance liquid chromatography-UV detector(HPLC-UV).Those results indicated that the developed LFA is an accurate and useful tool for on-site screening of TM in milk and animal tissues.
基金supported by the Scientific and Technological Research Project of Chongqing (CSTC2011ggB10009,cstc2012pt-kyys10002,cstc2012cx-rkxB10002)the National Natural Science Foundation of China(81202438)the Natural Science Foundation of the Chongqing Education Committee (KJ110605)
文摘To quantitatively determine tylosin and tilmicosin in edible animal tissues,a time-resolved fluoroimmunoassay(TRFIA) has been developed and validated.For this purpose,desmycosin-O-carboxymethoxylamine-BSA was fixed onto microtiter plates,standards and samples were loaded and,finally,diluted europium-labeled anti-tylosin antibodies were added.Results show that the limit of detection for tylosin was 0.03 ng mL-1 and that for tilmicosin was 0.05 ng mL-1.The recoveries were 73.6% to 120.5%,with coefficients of variation below 15.6% in various biological matrices spiked with tylosin and tilmicosin at concentrations of 50-200 ngg-1.There was good correlation(R2>0.99) between the TRFIA,an enzyme-linked immunosorbent assay and high performance liquid chromatography data.In conclusion,the new TRFIA is applicable to the detection of tylosin and tilmicosin and is an effective and economical method that will enable high-throughput sample screening.The method is expected to be widely applicable.
文摘试验旨在建立一种同时测定牛奶中替米考星(tilmicosin)、地塞米松(dexamethasone)、氟苯尼考(florfenicol)和氯霉素(chloramphenicol)的超高效液相色谱-串联质谱(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)法。牛奶样品经乙腈提取后,将提取液通过Oasis PRiME HLB固相萃取小柱净化,净化后的样液经氮吹浓缩后,用样品稀释液溶解并用正己烷进一步除去脂肪获得待分析样品,进行UPLCMS/MS分析。采用CAPCELL PAK C18MGIII-H色谱柱(2mm×100mm,3μm)进行液相色谱分离,以甲醇(A)-含0.01%甲酸的0.1mmol/L甲酸铵溶液(B)为流动相进行梯度洗脱:0~1.0min,90%至60%B;1.0~3.0min,60%至30%B;3.0~4.4min,30%至20%B;4.4~4.5min,20%~90%B;4.5~6.0min,90%B。在多反应监测(multiple reaction monitoring,MRM)模式下进行质谱测定,以基质匹配标准溶液外标法定量。结果显示,替米考星、地塞米松、氟苯尼考和氯霉素在1.0~100.0μg/L范围内均具有良好的线性关系(r>0.999)。方法的最低检测限(limits of detection,LODs)为0.1~0.2μg/kg,定量限(limits of quantity,LOQs)为0.2~0.5μg/kg,当4种化合物在牛奶中的添加水平为0.5、5.0和25.0μg/kg时,回收率为78.6%~94.7%,相对标准偏差(relative standard deviations,RSDs)为2.4%~10.1%。本试验建立的UPLC-MS/MS方法简便、灵敏、准确,适用于牛奶中替米考星、地塞米松、氟苯尼考和氯霉素的同时测定。
