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
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
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
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 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.
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.
