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Luo W, Meng K, Zhao Y, Liu J, Chen D, Xu C, Algharib SA, Dawood AS, Xie S. Guar gum modified tilmicosin-loaded sodium alginate/gelatin composite nanogels for effective therapy of porcine proliferative enteritis caused by Lawsonia intracellularis. Int J Biol Macromol 2023:125084. [PMID: 37245769 DOI: 10.1016/j.ijbiomac.2023.125084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/15/2023] [Accepted: 05/23/2023] [Indexed: 05/30/2023]
Abstract
In order to overcome the treatment difficulty of Lawsonia intracellularis (L.intracellularis) using antibiotics, the tilmicosin (TIL)-loaded sodium alginate (SA)/gelatin composite nanogels modified with bioadhesive substances were designed. The optimized nanogels were prepared by electrostatic interaction between SA and gelatin at a mass ratio of 1:1 and CaCl2 as an ionic crosslinker and further modified with guar gum (GG). The optimized TIL-nanogels modified with GG had a uniform spherical shape with a diameter of 18.2 ± 0.3 nm, LC of 29.4 ± 0.2 %, EE of 70.4 ± 1.6 %, PDI of 0.30 ± 0.04, and ZP of -32.2 ± 0.5 mv. The FTIR, DSC, and PXRD showed that GG was covered on the surface of TIL-nanogels in a pattern of staggered arrangements. The TIL-nanogels modified with GG had the strongest adhesive strength amongst those with I-carrageenan and locust bean gum and the plain nanogels, and thus significantly enhanced the cellular uptake and accumulation of TIL via clathrin-mediated endocytosis. It exhibited an increased therapeutic effect against L.intracellularis in vitro and in vivo. This study will provide guidance for developing nanogels for intracellular bacterial infection treatment.
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Affiliation(s)
- Wanhe Luo
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Engineering Laboratory for Tarim Animal Diseases Diagnosis and Control, College of Animal Science and Technology, Tarim University, Alar, Xinjiang 843300, China
| | - Kuiyu Meng
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Yiqing Zhao
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Jinhuan Liu
- Engineering Laboratory for Tarim Animal Diseases Diagnosis and Control, College of Animal Science and Technology, Tarim University, Alar, Xinjiang 843300, China
| | - Dongmei Chen
- MARA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Chunyan Xu
- Engineering Laboratory for Tarim Animal Diseases Diagnosis and Control, College of Animal Science and Technology, Tarim University, Alar, Xinjiang 843300, China
| | - Samah Attia Algharib
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Department of Clinical Pathology, Faculty of Veterinary Medicine, Benha University, Moshtohor, Toukh 13736, QG, Egypt
| | - Ali Sobhy Dawood
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Medicine and Infectious Diseases Department, Faculty of Veterinary Medicine, University of Sadat City, 32897, Egypt
| | - Shuyu Xie
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
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Luo W, Qin H, Chen D, Wu M, Meng K, Zhang A, Pan Y, Qu W, Xie S. The dose regimen formulation of tilmicosin against Lawsonia intracellularis in pigs by pharmacokinetic-pharmacodynamic (PK-PD) model. Microb Pathog 2020; 147:104389. [PMID: 32707311 DOI: 10.1016/j.micpath.2020.104389] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 06/11/2020] [Accepted: 07/07/2020] [Indexed: 11/25/2022]
Abstract
In this study, the rational dose regimens of tilmicosin against Lawsonia intracellularis (L. intracellularis) were studied using pharmacokinetic-pharmacodynamic (PK-PD) model approach to provide a maximal efficacy. The healthy and infected pigs were orally administrated the tilmicosin premix at a single dose of 10 mg/kg, and then the plasma and ileum content were collected at different time points. The time to peak (Tmax), the peak concentration (Cmax), the area under concentration time curve (AUC0-24h), the apparent volume of distribution by bioavailability (V/F), the body clearance rate by bioavailability (CL/F) and the mean residence time (MRT) of tilmicosin premix for plasma were 2.00 h, 1.08 ± 0.04 μg/mL, 9.61 ± 1.47 μg h/mL, 34.43 ± 1.02 L/kg, 0.71 ± 0.03 L/h/kg and 15.03 ± 0.04 h in healthy pigs, and 2.00 h, 0.99 ± 0.03 μg/mL, 9.30 ± 1.43 μg h/mL, 58.59 ± 1.81 L/kg, 0.44 ± 0.02 L/h/kg and 15.75 ± 0.03 h in infected pigs, respectively. The Tmax, Cmax, AUC0-24h, V/F, CL/F and MRT of tilmicosin premix for ileum content were 2.00 h, 3.78 ± 0.03 μg/mL, 20.41 ± 1.64 μg h/mL, 11.29 ± 0.97 L/kg, 0.44 ± 0.02 L/h/kg and 11.29 ± 0.09 h in healthy pigs, and 2.00 h, 3.41 ± 0.06 μg/mL, 22.65 ± 1.32 μg h/mL, 8.16 ± 1.51 L/kg, 0.41 ± 0.01 L/h/kg and 11.44 ± 0.05 h in infected pigs, respectively. Based on the intracellular minimum inhibitory concentration (MIC) of L. intracellularis isolate was 2 μg/mL, the results of the mutant prevention concentration (MPC), the post-antibiotic effect (PAE) and time-killing curves all showed strong concentration-dependenttendencies. Integrating the in vivo pharmacokinetic data of infected pigs and ex vivo pharmacodynamic data using the sigmoid Emax (Hill) equation to obtain the ileum content AUC0-24h/MIC values of 6.87, 26.80, and 36.02 h to achieve the bacteriostatic activity, bactericidal activity, and virtual eradication of bacteria, respectively. Based on these results, a dosage regimen of daily 14.39 mg/kg for 3 d could be sufficient in the treatment of L. intracellularis. This study will provide a guidance of dosage regimen formulation for drug against animal intracellular bacterial infections.
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Affiliation(s)
- Wanhe Luo
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China
| | - Hua Qin
- Beijing TEAM Junwei Healthcare Technology Development Co., Ltd., Beijing, 102600, China
| | - Dongmei Chen
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China; MARA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Mengru Wu
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China
| | - Kuiyu Meng
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China
| | - Aoxue Zhang
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China
| | - Yunahu Pan
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China
| | - Wei Qu
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China
| | - Shuyu Xie
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MARA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China.
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Maes D, Boyen F, Haesebrouck F, Gautier-Bouchardon AV. Antimicrobial treatment of Mycoplasma hyopneumoniae infections. Vet J 2020; 259-260:105474. [PMID: 32553237 DOI: 10.1016/j.tvjl.2020.105474] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 12/13/2022]
Abstract
Mycoplasma hyopneumoniae (M. hyopneumoniae) is the primary agent of enzootic pneumonia, a chronic and economically important respiratory disease of pigs. Control and prevention of M. hyopneumoniae infections can be accomplished by optimization of management and housing conditions, and by vaccination. The present paper summarizes the current knowledge on the main characteristics and efficacy of antimicrobials used for the treatment of clinical M. hyopneumoniae infections, the in vitro and in vivo activities of these antimicrobials and the reported resistance mechanisms against some. Potentially active antimicrobials against M. hyopneumoniae include tetracyclines, macrolides, lincosamides, pleuromutilins, amphenicols, aminoglycosides, aminocyclitols and fluoroquinolones. Antimicrobial treatment can be administered either orally or parenterally. Based on the overall results of efficacy studies performed under experimental and/or field conditions, the majority of agents belonging to these antimicrobial classes improved clinical parameters (clinical signs, lung lesions) and reduced performance losses due to M. hyopneumoniae infection. Antimicrobials may, however, not be able to prevent infection or to eradicate the bacterium from the respiratory tract. The decision to medicate should, therefore, be considered carefully. M. hyopneumoniae shows an intrinsic resistance against β-lactam antibiotics, sulfonamides and trimethoprim. A few reports have shown acquired antimicrobial resistance against some antibiotics, along with associated resistance mechanisms. The results of antimicrobial susceptibility testing are difficult to interpret in terms of treatment outcome, as no clinical breakpoints have been defined for M. hyopneumoniae.
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Affiliation(s)
- Dominiek Maes
- Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
| | - Filip Boyen
- Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | | | - Anne V Gautier-Bouchardon
- Mycoplasmology, Bacteriology and Antimicrobial Resistance Unit, Ploufragan-Plouzané-Niort Laboratory, French Agency for Food, Environmental and Occupational Health and Safety (Anses), France
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Dong Z, Zhou XZ, Sun JC, Meng XB, Li HS, Cheng FS, Wei XJ, Li B, Wang WW, Zhang JY. Efficacy of enteric-coated tilmicosin granules in pigs artificially infected with Actinobacillus pleuropneumoniae serotype 2. Vet Med Sci 2019; 6:105-113. [PMID: 31589010 PMCID: PMC7036302 DOI: 10.1002/vms3.198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 08/01/2019] [Accepted: 08/30/2019] [Indexed: 01/29/2023] Open
Abstract
Background Porcine infectious pleuropneumonia caused by Actinobacillus pleuropneumoniae (App) is one of the most serious infectious diseases in pigs and has brought huge economic losses to the world pig industry. The aim of this trial was to evaluate the effect of enteric‐coated tilmicosin granule in the treatment and control of artificial infection of App. Methods Sixty Duroc and Yorkshire crossbred pigs (50 of which were artificially infected) were divided into six groups: BCG (Blank control group), ICG (Infection‐only control group), HDG (High‐dose enteric‐coated tilmicosin granules), MDG (Medium‐dose enteric‐coated tilmicosin granules), LDG (Low‐dose enteric‐coated tilmicosin granules) and TPG (Tilmicosin premix drug control group). The cure rate, mortality, clinical respiratory score, body temperature score, weight gain, lung score and so on were recorded. Results The cure rate of HDG and MDG was as high as 90%, the mortality was 10%, and the clinical signs recovered quickly. Conclusion The results showed that enteric‐coated tilmicosin granules had obvious therapeutic effect on artificial infection, which could reduce the damage caused by the disease and reduce the mortality.
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Affiliation(s)
- Zhen Dong
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of Animal Drug production in Ministry of Agriculture, Gansu Province, P. R. China.,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of New Veterinary Medicine Engineering in Gansu Province, Gansu Province, P. R. China
| | - Xu-Zheng Zhou
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of Animal Drug production in Ministry of Agriculture, Gansu Province, P. R. China.,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of New Veterinary Medicine Engineering in Gansu Province, Gansu Province, P. R. China
| | - Ji-Chao Sun
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of Animal Drug production in Ministry of Agriculture, Gansu Province, P. R. China.,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of New Veterinary Medicine Engineering in Gansu Province, Gansu Province, P. R. China
| | - Xiao-Bin Meng
- Ringpu Biopharmaceutical Co., Ltd, Tianjin, P. R. China
| | - Hong-Sheng Li
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Veterinary Medicine Engineering Technology Research Centre Gansu Province, Gansu Province, P. R. China
| | - Fu-Sheng Cheng
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of Animal Drug production in Ministry of Agriculture, Gansu Province, P. R. China.,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of New Veterinary Medicine Engineering in Gansu Province, Gansu Province, P. R. China
| | - Xiao-Juan Wei
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of Animal Drug production in Ministry of Agriculture, Gansu Province, P. R. China.,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of New Veterinary Medicine Engineering in Gansu Province, Gansu Province, P. R. China
| | - Bing Li
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of Animal Drug production in Ministry of Agriculture, Gansu Province, P. R. China.,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of New Veterinary Medicine Engineering in Gansu Province, Gansu Province, P. R. China
| | - Wei-Wei Wang
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of Animal Drug production in Ministry of Agriculture, Gansu Province, P. R. China.,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of New Veterinary Medicine Engineering in Gansu Province, Gansu Province, P. R. China
| | - Ji-Yu Zhang
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of Animal Drug production in Ministry of Agriculture, Gansu Province, P. R. China.,Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of New Veterinary Medicine Engineering in Gansu Province, Gansu Province, P. R. China
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Xiong J, Zhu Q, Yang S, Zhao Y, Cui L, Zhuang F, Qiu Y, Cao J. Comparison of pharmacokinetics of tilmicosin in healthy pigs and pigs experimentally infected with Actinobacillus pleuropneumoniae. N Z Vet J 2019; 67:257-263. [PMID: 31208293 DOI: 10.1080/00480169.2019.1633434] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Aim: To compare the pharmacokinetic profiles of tilmicosin, administered orally at a single dose of 20 mg/kg bodyweight, in healthy pigs and in pigs experimentally infected with Actinobacillus pleuropneumoniae. Methods: Twelve healthy crossbred pigs, aged approximately 8 weeks, were randomly assigned to uninfected and infected groups, with six pigs per group. Pigs in the infected group were inoculated intranasally with a bacterial suspension of A. pleuropneumoniae containing approximately 108 cfu. Each pig received a single oral dose of 20 mg/kg bodyweight of tilmicosin, given 3-4 hours after inoculation in infected pigs. Blood samples were collected before drug administration and up to 48 hours after tilmicosin administration. Concentrations of tilmicosin in plasma samples were determined by HPLC. Throughout the experimental period pigs were observed for signs of inappetence and clinical abnormalities. After sampling was complete pigs were subject to euthanasia and samples collected for gross and histopathology as well as microbiology. Results: Infected pigs showed signs of bradykinesia, nasal discharge dyspnoea, and coughing 1 hours after inoculation and A. pleuropneumoniae was cultured from the lungs of all infected pigs postmortem. Comparing pharmacokinetic parameters in uninfected and infected pigs, the maximum plasma concentration of tilmicosin was higher in uninfected pigs (1.17 (SD 0.17) vs. 0.96 (SD 0.17) µg/mL), the time to reach maximum concentration was shorter (1.53 (SD 0.23) vs. 2.40 (SD 0.37) hours), and the half-life of the absorption phase and half-life of the elimination phase were both shorter (0.66 (SD 0.08) vs. 1.00 (SD 0.27) hours) and (12.93 (SD 0.96) vs. 16.53 (SD 0.55) hours), respectively. The apparent volume of distribution was smaller in uninfected than infected pigs (1.91 (SD 0.22) vs. 2.16 (SD 0.21) L/kg). The relative bioavailability of tilmicosin in infected relative to uninfected pigs was 108.6 (SD 9.71)%. Conclusions and clinical relevance: The results of this study indicate that A. pleuropneumoniae infection significantly changed certain pharmacokinetic parameters of tilmicosin in pigs. In infected pigs tilmicosin exhibited a longer drug persistence and a better extent of absorption. These results indicate that it is necessary to monitor and adjust the dose of tilmicosin administration during the presence of pleuropneumonia. It is expected that this can optimise clinical efficacy and help avoid the development of resistance.
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Affiliation(s)
- J Xiong
- a Department of Veterinary Pharmacology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Q Zhu
- a Department of Veterinary Pharmacology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - S Yang
- a Department of Veterinary Pharmacology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Y Zhao
- a Department of Veterinary Pharmacology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - L Cui
- b Department of Veterinary Pathology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - F Zhuang
- c Hubei Key Laboratory of Animal Nutrition and Feed Science , Hubei Collaborative Innovation Centre for Animal Nutrition and Feed Safety, Wuhan Polytechnic University , Wuhan , People's Republic of China
| | - Y Qiu
- c Hubei Key Laboratory of Animal Nutrition and Feed Science , Hubei Collaborative Innovation Centre for Animal Nutrition and Feed Safety, Wuhan Polytechnic University , Wuhan , People's Republic of China
| | - J Cao
- a Department of Veterinary Pharmacology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
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Xiong J, Zhu Q, Zhao Y, Yang S, Cao J, Qiu Y. Tilmicosin enteric granules and premix to pigs: Antimicrobial susceptibility testing and comparative pharmacokinetics. J Vet Pharmacol Ther 2019; 42:336-345. [PMID: 30801755 DOI: 10.1111/jvp.12753] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 01/22/2019] [Accepted: 01/28/2019] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to compare the pharmacokinetics and relative bioavailability of tilmicosin enteric granules and premix after oral administration at a dose of 40 mg/kg in pigs. Three kinds of different respiratory pathogens were selected for determination of minimal inhibitory concentration (MIC) to tilmicosin. Eight healthy pigs were assigned to a two-period, randomized crossover design. A modified rapid, sensitive HPLC method was used for determining the concentrations of tilmicosin in plasma. Pharmacokinetic parameters were calculated by using WinNonlin 5.2 software. The MIC90 of tilmicosin against Haemophilus parasuis, Actinbacillus pleuropneumoniae, and Pasteurella multocida were all 8 μg/ml. These results indicated that these common pig respiratory bacteria are sensitive to tilmicosin. The main parameters of time to reach maximum plasma concentration (Tmax ), elimination half-life (t1/2β ), mean residence time (MRT), and apparent volume of distribution (VF ) were 2.03 ± 0.37 hr, 29.31 ± 5.56 hr, 25.22 ± 2.57 hr, 4.06 ± 1.04 L/kg, and 3.05 ± 0.08 hr, 17.06 ± 1.77 hr, 15.55 ± 1.37 hr, 2.95 ± 0.62 L/kg after the orally administrated tilmicosin enteric granules and premix. The relative bioavailability of tilmicosin enteric granules to premix was 114.97 ± 7.19%, according to the AUC0-t values. These results demonstrated that tilmicosin enteric granules produced faster tilmicosin absorption, slower elimination, larger tissue distribution, and higher bioavailability compared to the tilmicosin premix. The present study results manifest that tilmicosin enteric granules can be used as a therapeutic alternative to premix in clinical treatment.
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Affiliation(s)
- Jincheng Xiong
- Department of Veterinary Pharmacology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Reference Laboratory of Veterinary Drug Residues and Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China
| | - Qianqian Zhu
- Department of Veterinary Pharmacology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Reference Laboratory of Veterinary Drug Residues and Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China
| | - Yaxin Zhao
- Department of Veterinary Pharmacology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Shuaike Yang
- Department of Veterinary Pharmacology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Reference Laboratory of Veterinary Drug Residues and Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China
| | - Jiyue Cao
- Department of Veterinary Pharmacology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,National Reference Laboratory of Veterinary Drug Residues and Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China
| | - Yinsheng Qiu
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan Polytechnic University, Wuhan, China
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Ling Z, Yonghong L, Junfeng L, Li Z, Xianqiang L. Tilmicosin- and florfenicol-loaded hydrogenated castor oil-solid lipid nanoparticles to pigs: Combined antibacterial activities and pharmacokinetics. J Vet Pharmacol Ther 2017; 41:307-313. [PMID: 29139136 DOI: 10.1111/jvp.12465] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 10/03/2017] [Indexed: 11/26/2022]
Abstract
The combined antibacterial effects of tilmicosin (TIL) and florfenicol (FF) against Actinobacillus pleuropneumoniae (APP) (n = 2), Streptococcus suis (S. suis) (n = 2), and Haemophilus parasuis (HPS) (n = 2) were evaluated by chekerboard test and time-kill assays. The pharmacokinetics (PKs) of TIL- and FF-loaded hydrogenated castor oil (HCO)-solid lipid nanoparticles (SLN) were performed in healthy pigs. The results indicated that TIL and FF showed synergistic or additive antibacterial activities against APP, S. suis and HPS with the fractional inhibitory concentration (FIC) ranging from 0.375 to 0.75. The time-kill assays showed that 1/2 minimum inhibitory concentration (MIC) TIL combined with 1/2 MIC FF had a stronger ability to inhibit the growth of APP, S. suis, and HPS than 1 MIC TIL or 1 MIC FF, respectively. After oral administration, plasma TIL and FF concentrations could maintain about 0.1 μg/ml for 192 and 176 hr. The SLN prolonged the last time point with detectable concentrations (Tlast ), area under the concentration-time curve (AUC0-t ), elimination half-life (T½ke ), and mean residence time (MRT) by 3.1, 5.6, 12.7, 3.4-fold of the active pharmaceutical ingredient (API) of TIL and 11.8, 16.5, 18.1, 12.1-fold of the API of FF, respectively. This study suggests that the TIL-FF-SLN could be a useful oral formulation for the treatment of APP, S. suis, and HPS infection in pigs.
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Affiliation(s)
- Z Ling
- College of Animal Science and Technology, Tarim University, Alar, Xinjiang, China.,Key Laboratory of Tarim Animal Husbandry Science and Technology of Xinjiang Production & Construction Corps, Alar, China.,College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - L Yonghong
- College of Animal Science and Technology, Tarim University, Alar, Xinjiang, China.,Key Laboratory of Tarim Animal Husbandry Science and Technology of Xinjiang Production & Construction Corps, Alar, China
| | - L Junfeng
- Key Laboratory of Tarim Animal Husbandry Science and Technology of Xinjiang Production & Construction Corps, Alar, China
| | - Z Li
- College of Animal Science and Technology, Tarim University, Alar, Xinjiang, China.,Key Laboratory of Tarim Animal Husbandry Science and Technology of Xinjiang Production & Construction Corps, Alar, China
| | - L Xianqiang
- College of Animal Science and Technology, Tarim University, Alar, Xinjiang, China.,Key Laboratory of Tarim Animal Husbandry Science and Technology of Xinjiang Production & Construction Corps, Alar, China
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8
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Toutain PL, Potter T, Pelligand L, Lacroix M, Illambas J, Lees P. Standard PK/PD concepts can be applied to determine a dosage regimen for a macrolide: the case of tulathromycin in the calf. J Vet Pharmacol Ther 2016; 40:16-27. [DOI: 10.1111/jvp.12333] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 05/08/2016] [Indexed: 11/30/2022]
Affiliation(s)
- P.-L. Toutain
- UMR 1331 Toxalim INRA; École Nationale Vétérinaire de Toulouse; Toulouse Cedex 03 France
| | - T. Potter
- The Royal Veterinary College; Hatfield Hertfordshire UK
| | - L. Pelligand
- The Royal Veterinary College; Hatfield Hertfordshire UK
| | - M. Lacroix
- UMR 1331 Toxalim INRA; École Nationale Vétérinaire de Toulouse; Toulouse Cedex 03 France
| | - J. Illambas
- The Royal Veterinary College; Hatfield Hertfordshire UK
| | - P. Lees
- The Royal Veterinary College; Hatfield Hertfordshire UK
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9
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Shryock TR, Staples JM, DeRosa DC. Minimum Inhibitory Concentration Breakpoints and Disk Diffusion Inhibitory Zone Interpretive Criteria for Tilmicosin Susceptibility Testing against Pasteurella Multocida and Actinobacillus Pleuropneumoniae Associated with Porcine Respiratory Disease. J Vet Diagn Invest 2016; 14:389-95. [PMID: 12296390 DOI: 10.1177/104063870201400505] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Tilmicosin is a novel macrolide antibiotic developed for exclusive use in veterinary medicine. Tilmicosin has been approved as a feed premix to control porcine respiratory disease associated with Pasteurella multocida and Actinobacillus pleuropneumoniae. The development of antimicrobial susceptibility testing guidelines for tilmicosin was predicated on the relationship of clinical efficacy studies that demonstrated a favorable therapeutic outcome, on pharmacokinetic data, and on in vitro test data, as recommended by the National Committee for Clinical Laboratory Standards (NCCLS). The approved breakpoints for the minimum inhibitory concentration dilution testing for both species are resistant, ≥32 μg/ml, and susceptible, ≤16 μg/ml. The zone of inhibition interpretive criteria for disk diffusion testing with a 15-μg tilmicosin disk are resistant, ≤10 mm, and susceptible, ≥11mm.
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10
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Rottbøll LAH, Friis C. Penetration of antimicrobials to pulmonary epithelial lining fluid and muscle and impact of drug physicochemical properties determined by microdialysis. J Pharmacol Toxicol Methods 2015; 78:58-65. [PMID: 26645525 DOI: 10.1016/j.vascn.2015.11.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/26/2015] [Accepted: 11/27/2015] [Indexed: 11/15/2022]
Abstract
INTRODUCTION The objectives of this study were to characterize antimicrobial drug penetration into the pulmonary epithelial lining fluid (PELF) and extracellular fluid (ECF) of muscle in relation to physicochemical properties of the drugs (molecular mass, Log D, polar surface area and charge), using intrabronchial microdialysis. The series of drugs tested include gentamicin, sulfadiazine, cefquinome, minocycline and colistin. METHODS Drug concentrations were measured during 2h of steady state plasma drug concentrations at therapeutic levels in anesthetized pigs. Microdialysis probes were positioned 2 to 4cm distal to the tracheal bifurcature and in M. gluteobiceps and were calibrated by retrodialysis by drug. RESULTS Mean AUCPELF/PLASMA(fu) and mean AUCMUSCLE/PLASMA(fu) ratios were respectively for gentamicin (0.8, 0.7), sulfadiazine (1.1, 0.7), cefquinome (1.3, 1.5) minocycline (1.6, 0.7) and colistin (0.26, 0.12). The penetration of drugs into PELF (r(2)=0.55-0.77, p=0.0004-0.0089) and ECF of muscle (r(2)=0.39-0.53, p=0.0108-0.0397) was positively correlated to Log D, whereas molecular mass, polar surface area and charge were negatively correlated to drug penetration. Sulfadiazine, gentamicin, cefquinome and colistin had similar penetration ratios into PELF and ECF of muscle, ranging from 0.12 to 1.50. DISCUSSION In conclusion, drug penetration into PELF and ECF of muscle is correlated to mass, lipophilicity, polarity and charge of the drugs. Drug partition into ECF of muscle and PELF are similar for the passively transported drugs gentamicin, sulfadiazine, cefquinome and colistin, whereas minocycline appears to be actively transported into PELF.
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Affiliation(s)
- Lisa Amanda Holm Rottbøll
- University of Copenhagen, Faculty of Health and Medical Sciences, Department of Veterinary Disease Biology, Veterinary Pharmacology and Toxicology, Denmark.
| | - Christian Friis
- University of Copenhagen, Faculty of Health and Medical Sciences, Department of Veterinary Disease Biology, Veterinary Pharmacology and Toxicology, Denmark.
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11
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Parsons CG, Ruitenberg M, Freitag CE, Sroka-Saidi K, Russ H, Rammes G. MRZ-99030 - A novel modulator of Aβ aggregation: I - Mechanism of action (MoA) underlying the potential neuroprotective treatment of Alzheimer's disease, glaucoma and age-related macular degeneration (AMD). Neuropharmacology 2015; 92:158-69. [PMID: 25634238 DOI: 10.1016/j.neuropharm.2014.12.038] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 11/28/2014] [Accepted: 12/02/2014] [Indexed: 10/24/2022]
Abstract
Therapeutic approaches addressing β-amyloid1-42 (Aβ1-42) aggregation represent a promising neuroprotective strategy for the treatment of Alzheimer's disease, dry age-related macular degeneration (AMD) and glaucoma. MRZ-99030 is a dipeptide containing d-tryptophan and 2-amino-2-methylpropionic acid in clinical development for the topical treatment of glaucoma and AMD. MRZ-99030 is an Aβ aggregation modulator, previously reported to prevent the formation of soluble toxic oligomeric Aβ species. The present study confirmed that MRZ-99030 prevents the formation of oligomeric Aβ species using similar SDS-PAGE experiments. However, additional data from TR-FRET, DLS and AFM experiments revealed that MRZ-99030 does not directly prevent early protein/protein interactions between monomeric Aβ, but rather promotes the formation of large, non-amyloidogenic, amorphous Aβ aggregates and thereby reduces the amount of intermediate toxic soluble oligomeric Aβ species. The affinity of MRZ-99030 to Aβ1-42 determined by SPR was 28.4 nM but the ratio of compound to Aβ is also important: a 10-20 fold excess of MRZ-99030 over Aβ is probably required for effective modulation of protein/protein interactions. For example, in glaucoma, assuming a maximal Aβ concentration of 1-15 nM in the retina, up to 150 nM MRZ-99030 could be required at the protein target. In line with this consideration, MRZ-99030 was able to prevent Aβ-induced toxicity on PC12 cells, retinal ganglion cells and retinal pigment epithelium cells when present at a 10-20 fold stoichiometric excess over Aβ. Moreover, in vivo studies demonstrate the neuroprotective potential of MRZ-99030 after systemic and topical administration in animal models of Alzheimer's disease and glaucoma/AMD respectively.
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Affiliation(s)
| | - Maarten Ruitenberg
- Merz Pharmaceuticals, Eckenheimer Landstrasse 100, D-60318 Frankfurt, Germany
| | - Christine E Freitag
- Merz Pharmaceuticals, Eckenheimer Landstrasse 100, D-60318 Frankfurt, Germany
| | - Kamila Sroka-Saidi
- Merz Pharmaceuticals, Eckenheimer Landstrasse 100, D-60318 Frankfurt, Germany
| | - Hermann Russ
- Merz Pharmaceuticals, Eckenheimer Landstrasse 100, D-60318 Frankfurt, Germany
| | - Gerhard Rammes
- Department of Anaesthesiology, Technische Universität München, D-81675, Germany
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12
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Del Pozo Sacristán R, Rodríguez AL, Sierens A, Vranckx K, Boyen F, Dereu A, Haesebrouck F, Maes DGD. Efficacy of in-feed medication with chlortetracycline in a farrow-to-finish herd against a clinical outbreak of respiratory disease in fattening pigs. Vet Rec 2012; 171:645. [PMID: 23136309 DOI: 10.1136/vr.100976] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The efficacy of chlortetracycline (CTC) in-feed medication to treat pigs with clinical respiratory disease was investigated in a farrow-to-finish pig herd infected with Mycoplasma hyopneumoniae, and with clinical respiratory disease in growing pigs. In total, 533 pigs were included. The animals were vaccinated against M hyopneumoniae and porcine circovirus type 2 at weaning. At onset of clinical respiratory disease, they were randomly allocated to one of the following treatment groups: chlortetracycline 1 (CTC1) (two consecutive weeks, 500 ppm), chlortetracycline 2 (CTC2) (two non-consecutive weeks, with a non-medicated week interval in between, 500 ppm) or tylosin (T) (three consecutive weeks, 100 ppm). Performance (daily weight gain, feed conversion ratio), pneumonia lesions at slaughter and clinical parameters (respiratory disease score) were assessed. Only numeric differences in favour of the CTC2 group were obtained for the performance and the clinical parameters. The prevalence of pneumonia lesions was 20.5, 13.1 and 23.0 per cent (P<0.05) for the CTC1, CTC2 and T groups, respectively. The study demonstrated that CTC, when administered at onset of clinical respiratory disease via the feed at a dose of 500 ppm during two alternative weeks, was able to decrease the prevalence of pneumonia lesions, and numerically reduce performance losses and clinical signs.
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Affiliation(s)
- R Del Pozo Sacristán
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke B-9820, Belgium.
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13
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Kinetics and intrapulmonary disposition of tilmicosin after single and repeated oral bolus administrations to rabbits. Vet Res Commun 2010; 34 Suppl 1:S69-72. [DOI: 10.1007/s11259-010-9385-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abu-Basha EA, Idkaidek NM, Al-Shunnaq AF. Pharmacokinetics of Tilmicosin (Provitil Powder and Pulmotil Liquid AC) Oral Formulations in Chickens. Vet Res Commun 2007; 31:477-85. [PMID: 17225089 DOI: 10.1007/s11259-006-3543-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2005] [Indexed: 10/23/2022]
Abstract
A bioavailability and pharmacokinetics study of powder and liquid tilmicosin formulations was carried out in 18 healthy chickens according to a single-dose, two-period, two-sequence, crossover randomized design. The two formulations were Provitil and Pulmotil AC. Both drugs were administered to each chicken after an overnight fast on two treatment days separated by a 2-week washout period. A modified rapid and sensitive HPLC method was used for determination of tilmicosin concentrations in chicken plasma. Various pharmacokinetic parameters including area under plasma concentration-time curve (AUC(0-72)), maximum plasma concentration (C(max)), time to peak concentration (t(max)), elimination half-life (t(1/2beta)), elimination rate (k(el)), clearance (Cl(B)), mean residence time (MRT) and volume of distribution (V(d,area)) were determined for both formulations. The average means of AUC(0-72) for Provitil and Pulmotil AC were very close (24.24 +/- 3.86, 21.82 +/- 3.14 (microg x h)/ml, respectively), with no significant differences based on ANOVA. The relative bioavailability of Provitil as compared to Pulmotil AC was 111%. In addition, there were no significant differences in the C(max) (2.09 +/- 0.37, 2.12 +/- 0.40 microg/ml), tmax (3.99 +/- 0.84, 5.82 +/- 1.04 h), t(1/2beta) (47.4 +/- 9.32, 45.0 +/- 5.73 h), k(el) (0.021 +/- 0.0037, 0.022 +/- 0.0038 h(-1)), Cl(B) (19.73 +/- 3.73, 21.37 +/- 4.54ml/(min/kg)), MRT (71.20 +/- 12.87, 67.15 +/- 9.01 h) and V(d,area) (1024.8 +/- 87.5, 1009.8 +/- 79.5 ml/kg) between Pulmotil AC and Provitil, respectively. In conclusion, tilmicosin was rapidly absorbed and slowly eliminated after oral administration of single dose of tilmicosin aqueous and powder formulations. Provitil and Pulmotil AC can be used as interchangeable therapeutic agents.
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Affiliation(s)
- E A Abu-Basha
- Department of Veterinary Basic Medical Sciences, Faculty of Veterinary Medicine, Jordan University of Science and Technology, Irbid, Jordan.
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15
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Womble A, Giguère S, Murthy YVSN, Cox C, Obare E. Pulmonary disposition of tilmicosin in foals and in vitro activity against Rhodococcus equi and other common equine bacterial pathogens. J Vet Pharmacol Ther 2006; 29:561-8. [PMID: 17083461 DOI: 10.1111/j.1365-2885.2006.00804.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The objectives of this study were to determine the serum and pulmonary disposition of tilmicosin in foals and to investigate the in vitro activity of the drug against Rhodococcus equi and other common bacterial pathogens of horses. A single dose of a new fatty acid salt formulation of tilmicosin (10 mg/kg of body weight) was administered to seven healthy 5- to 8-week-old foals by the intramuscular route. Concentrations of tilmicosin were measured in serum, lung tissue, pulmonary epithelial lining fluid (PELF), bronchoalveolar lavage (BAL) cells, and blood neutrophils. Mean peak tilmicosin concentrations were significantly different between sampling sites with highest concentrations measured in blood neutrophils (66.01+/-15.97 microg/mL) followed by BAL cells (20.1+/-5.1 microg/mL), PELF (2.91+/-1.15 microg/mL), lung tissue (1.90+/-0.65 microg/mL), and serum (0.19+/-0.09 microg/mL). Harmonic mean terminal half-life in lung tissue (193.3 h) was significantly longer than that of PELF (73.3 h), bronchoalveolar cells (62.2 h), neutrophils (47.9 h), and serum (18.4 h). The MIC90 of 56 R. equi isolates was 32 microg/mL. Tilmicosin was active in vitro against most streptococci, Staphylococcus spp., Actinobacillus spp., and Pasteurella spp. The drug was not active against Enterococcus spp., Pseudomonas spp., and Enterobacteriaceae.
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Affiliation(s)
- A Womble
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA
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16
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Nerland EM, LeBlanc JM, Fedwick JP, Morck DW, Merrill JK, Dick P, Paradis MA, Buret AG. Effects of oral administration of tilmicosin on pulmonary inflammation in piglets experimentally infected with Actinobacillus pleuropneumoniae. Am J Vet Res 2005; 66:100-7. [PMID: 15691043 DOI: 10.2460/ajvr.2005.66.100] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES To determine the effects of oral administration of tilmicosin in piglets experimentally infected with Actinobacillus pleuropneumoniae. ANIMALS Forty 3-week-old specific-pathogen free piglets. PROCEDURES Piglets were assigned to 1 of 4 groups as follows: 1) uninfected sham-treated control piglets; 2) infected untreated piglets that were intratracheally inoculated with 10(7) CFUs of A pleuropneumoniae; 3) infected treated piglets that were intratracheally inoculated with A pleuropneumoniae and received tilmicosin in feed (400 ppm [microg/g]) for 7 days prior to inoculation; or 4) infected treated piglets that were intratracheally inoculated with A pleuropneumoniae and received chlortetracycline (CTC) in feed (1100 ppm [microg/gl) for 7 days prior to inoculation. Bronchoalveolar lavage (BAL) fluid and lung tissue specimens of piglets for each group were evaluated at 3 or 24 hours after inoculation. For each time point, 4 to 6 piglets/group were studied. RESULTS Feeding of CTC and tilmicosin decreased bacterial load in lungs of infected piglets. Tilmicosin delivered in feed, but not CTC, enhanced apoptosis in porcine BAL fluid leukocytes. This was associated with a decrease in LTB4 concentrations in BAL fluid of tilmicosin-treated piglets, compared with untreated and CTC-treated piglets, and also with a significant decrease in the number of pulmonary lesions. Tilmicosin inhibited infection-induced increases in rectal temperatures, as measured in untreated and CTC-treated piglets. Pulmonary neutrophil infiltration and prostaglandin E2 concentrations in the BAL fluid were not significantly different among groups at any time. CONCLUSIONS AND CLINICAL RELEVANCE Oral administration of tilmicosin to infected piglets induces apoptosis in BAL fluid leukocytes and decreases BAL fluid LTB4 concentrations and inflammatory lung lesions.
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Affiliation(s)
- Erin M Nerland
- Department of Biological Sciences, Mucosal Inflammation Research Group, University of Calgary, Calgary, AB T2N 1N4, Canada
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DeRosa DC, Veenhuizen MF, Bade DJ, Shryock TR. In vitro susceptibility of porcine respiratory pathogens to tilmicosin. J Vet Diagn Invest 2000; 12:541-6. [PMID: 11108454 DOI: 10.1177/104063870001200608] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Bacterial isolates obtained from swine with various clinical diseases were tested for susceptibility to tilmicosin by minimum inhibitory concentration (MIC) and Kirby-Bauer disk diffusion tests using National Committee on Clinical Laboratory Standards methodology. The tilmicosin MIC90 was < or =0.125 microg/ml for Erysiopelothrix rhusiopathiae, < or = 1 microg/ml for Haemophilus parasuis isolates, 8 microg/ml for Actinobacillus suis and Pasteurella multocida type A, 16 microg/ml for toxigenic and nontoxigenic P. multocida type D, 64 microg/ml for Bordetella bronchiseptica, and >128 microg/ml for Staphylococcus hyicus and Streptococcus suis. The results of disk diffusion testing matched well with the MIC results for each pathogen. This in vitro survey of tilmicosin activity against various swine isolates suggests that further clinical evaluation of tilmicosin in swine may be warranted for disease associated with E. rhusiopathiae, H. parasuis, and A. suis but not B. bronchiseptica, S. suis, or S. hyicus.
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Affiliation(s)
- D C DeRosa
- Elanco Animal Health, Greenfield, IN 46140, USA
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Scorneaux B, Shryock TR. The determination of the cellular volume of avian, porcine and bovine phagocytes and bovine mammary epithelial cells and its relationship to uptake of tilmicosin. J Vet Pharmacol Ther 1999; 22:6-12. [PMID: 10211711 DOI: 10.1046/j.1365-2885.1999.00185.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In order to compare the intracellular concentration of antimicrobial agents in phagocytic and nonphagocytic cells, the knowledge of their cell volume is essential. For the first time, the determination of the avian, porcine, and bovine polymorphonuclear neutrophils (PMN), monocyte-derived macrophages, macrophages, and bovine mammary epithelial cell volume was performed using [3H]-water and [14C]-carboxyinulin. The comparison of all the cells showed that the PMN have a size range between 3.58 and 4.04 microL per mg of protein, and are smaller than the monocyte-derived macrophages and mammary epithelial cells (4.32-5.01 microL per mg of protein). The macrophages show the largest size (5.84-6.57 microL per mg of protein). The cellular uptake of tilmicosin in these cells was then determined. The examination of the intracellular/extracellular concentration ratios (Ci/Ce) after 4 h of incubation with 10 mg/mL of [14C]-labelled tilmicosin revealed that tilmicosin was well accumulated and showed a ratio of 137, 169 and 193 in avian PMN, porcine PMN, and bovine alveolar macrophages, respectively. The cellular uptake data also demonstrated that tilmicosin accumulated in nonphagocytic bovine mammary epithelial cells. The importance of the use of the appropriate species and cell type specific cell volume values for calculations was exemplified by calculating the Ci/Ce of tilmicosin using cell volume data found in the literature for human and mouse cells. The subsequent comparison of these data with the Ci/Ce calculated with the actual cell volume appropriate for the species tested revealed an under evaluation of 3-13% in monocyte-macrophages, an over evaluation of 7-18%, 16-31% and 69% in PMN, macrophages, and epithelial cells, respectively. This study highlights the importance of the proper cell volume in order to determine the Ci/Ce. Moreover, the cell volumes determined here for avian, porcine and bovine cells should facilitate further in vitro and in vivo cellular studies by veterinary researchers.
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Affiliation(s)
- B Scorneaux
- Animal Science Research, Elanco Animal Health, Greenfield, IN 46140, USA
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