Amoxicillin—current use in swine medicine          下载免费PDF全文

D. G. S. Burch  D. Sperling 《Journal of veterinary pharmacology and therapeutics》2018,41(3):356-368

Amoxicillin has become a major antimicrobial substance in pig medicine for the treatment and control of severe, systemic infections such as Streptococcus suis. The minimum inhibitory concentration 90% (MIC 90) is 0.06 μg amoxicillin/ml, and the proposed epidemiological cut‐off value (ECOFF) is 0.5 μg/ml, giving only 0.7% of isolates above the ECOFF or of reduced susceptibility. Clinical breakpoints have not been set for amoxicillin against porcine pathogens yet, hence the use of ECOFFs. It has also been successfully used for bacterial respiratory infections caused by Actinobacillus pleuropneumoniae and Pasteurella multocida. The ECOFF for amoxicillin against A. pleuropneumoniae is also 0.5 μg/ml demonstrating only a reduced susceptibility in 11.3% of isolates. Similarly, P. multocida had an ECOFF of 1.0 μg/ml and a reduced susceptibility in only 2.6% of isolates. This reduced susceptibility disappears when combined with the beta‐lactamase inhibitor, clavulanic acid, demonstrating that it is primarily associated with beta‐lactamase production. In contrast, amoxicillin is active against Escherichia coli and Salmonella species but using ECOFFs of 8.0 and 4.0 μg/ml, respectively, reduced susceptibility can be seen in 70.9% and 67.7% of isolates. These high levels of reduced susceptibility are primarily due to beta‐lactamase production also, and most of this resistance can be overcome by the combination of amoxicillin with clavulanic acid. Currently, amoxicillin alone is considered an extremely valuable antimicrobial in both human and animal medicine and remains in the critically important category of antibiotics alongside the fluoroquinolones and macrolides by the World Health Organization as well as the third‐ and fourth‐generation cephalosporins, but these cephalosporins show marked resistance to basic beta‐lactamase production and are only destroyed by the extended‐spectrum beta‐lactamases. Amoxicillin alone and in combination with clavulanic acid are currently classed together in Category 2 in the European Union. By reviewing the pharmacodynamic data and comparing this with pharmacokinetic data from healthy and infected animals and clinical trial data, it can be seen that the product has a good efficacy against S. suis and A. pleuropneumoniae, in spite of usage over many years. However, it may be much less efficacious on its own against E. coli, due to reduced susceptibility and resistance associated with beta‐lactamase production, which is largely overcome by the use of clavulanic acid. It is felt that this differentiation may be useful in future classification of amoxicillin alone, in comparison with its combined use with clavulanic acid and thereby preserve the use of the more critically important antibiotics in veterinary medicine and reducing the risk of their resistance being transmitted to human.  相似文献   

猪圆环病毒病的病情变化趋势     

陈丽园  吴娟  白冰冰  Dayid Burch 《国外畜牧学(猪与禽)》2007,27(6):55-56

美国猪兽医师年会上提交了很多与猪Ⅱ型圆环病毒(PCV2)有关疾病的报告。人们对于仍在全球范围肆虐的猪Ⅱ型圆环病毒(PCV2)的了解正在日益增多。今年我们已从多个途径获得了有关此病的新信息,而最新的信息是在美国猪兽医  相似文献   

Special Sample Tray for the Continuous Gas-Flow Type Counter Tube     

Burch GE  Cronvich JA  Ray T  Reaser PB  Threefoot SA 《Science (New York, N.Y.)》1949,109(2838):516-517

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Comparative in vitro activity of valnemulin against porcine bacterial pathogens   总被引：1，自引：0，他引：1  

Aitken IA  Morgan JH  Dalziel R  Burch DG  Ripley PH 《The Veterinary record》1999,144(5):128

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圆环病毒通过鼻部扩散     

孟俊英  David Burch 《养猪》2007,(6):62-62

在波兰克拉克夫市举行的2007年国际兽医会议上,关于猪圆环病毒病的最新报道显示,对于仔猪断奶后多系统衰竭综合征(PMWS)的控制可能需要  相似文献   

Identification and characterisation of an H7N3 influenza A virus from an outbreak of virulent avian influenza in Victoria   总被引：1，自引：0，他引：1  

PW SELLECK  LJ GLEESON  FT HOOPER  HA WESTBURY  E. HANSSON 《Australian veterinary journal》1997,75(4):289-292

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A METHOD FOR MEASURING THE AREA OF SMALL IRREGULAR SURFACES OF THE HUMAN BODY     

Burch GE  Cohn AE  Neumann C 《Science (New York, N.Y.)》1941,93(2407):165-166

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Treatment of pigs experimentally infected with Mycoplasma hyopneumoniae, Pasteurella multocida, and Actinobacillus pleuropneumoniae with various antibiotics.   总被引：2，自引：0，他引：2  

L Stipkovits  D Miller  R Glavits  L Fodor    D Burch 《Canadian journal of veterinary research》2001,65(4):213-222

The authors have performed a comparative study of the efficacy of various in-feed medications for the treatment of 5- to 6-week-old specific pathogen-free (SPF) piglets experimentally infected on day 1 with Mycoplasma hyopneumoniae, on day 8 with Pasteurella multocida (serotype A), and on day 15 with Actinobacillus pleuropneumoniae (serotype 2). The treatment started on day 9 and continued for 12 consecutive days, then the piglets were euthanized for examination of macroscopic, histologic, and pathologic lesions and for the presence of mycoplasmas and bacteria in the lungs. Based on the results of clinical observations (respiratory signs, rectal temperature, body weight gain, and feed conversion efficiency), macroscopic and histologic lesions of the lungs, and microbiologic findings, the best results were obtained by treatment of pigs with Econor + chlortetracycline, followed by Tetramutin, Pulmotil, Cyfac, and lincomycin + chlortetracycline.  相似文献   

The synergistic activity of tiamulin and chlortetracycline: in-feed treatment of bacterially complicated enzootic pneumonia in fattening pigs   总被引：2，自引：0，他引：2  

D G Burch  G T Jones  T W Heard  R E Tuck 《The Veterinary record》1986,119(5):108-112

The antibacterial effects of a combination of tiamulin and chlortetracycline in vitro against a number of field isolates of Pasteurella multocida, Haemophilus pleuropneumoniae and Bordetella bronchiseptica were examined. There was a marked synergism between the two antibiotics against all eight isolates of P multocida, against seven of nine isolates of H pleuropneumoniae and against the single strain of B bronchiseptica tested. Two field trials were carried out on a herd with a history of complicated enzootic pneumonia where the presence of Mycoplasma hyopneumoniae and P multocida had been established and subsequently the presence of H pleuropneumoniae was discovered. Feed containing tiamulin at 100 ppm combined with chlortetracycline at 300 ppm was given for seven days to pigs affected with pneumonia, and the results were compared with untreated controls and pigs receiving chlortetracycline at 300 ppm. There was a follow-up observation period of three weeks when all groups received unmedicated feed. During the medication period the combination treated groups showed a statistically significant increase in average daily weight gain of 156 g (20.4 per cent) and in feed conversion efficiency of 0.576 (20.8 per cent) and a numerical improvement in average disease score in comparison with the untreated controls. These improvements were approximately double those observed in the groups treated with 300 ppm chlortetracycline which showed improvements of 93 g (12.2 per cent) in average daily gain and 0.301 (10.9 per cent) in feed conversion efficiency. During the following three weeks most of the initial gains were lost, probably owing to the reinfection of the treated groups by the untreated controls.  相似文献   

Exogenous paraoxonase‐1 during oocyte maturation improves bovine embryo development in vitro          下载免费PDF全文

JAA Rincón  EM Madeira  FT Campos  B Mion  JF Silva  VA Absalón‐Medina  WR Butler  MN Corrêa  LMC Pegoraro  A Schneider 《Reproduction in domestic animals》2016,51(5):827-830

Paraoxonase‐1 (PON1) is an enzyme found in serum and follicular fluid that protects cell membrane and circulating lipids against oxidative damage. The aims of this study were to measure the direct effects of recombinant PON1 (rPON1) on bovine oocyte maturation at the molecular level (gene expression) and to measure the carry‐over effects of PON1 on pre‐implantation embryo development in vitro. COCs were submitted to IVM with the addition of 0.0, 0.02, 0.04 and 0.08 mg ml^?1 of rPON1, corresponding to an average PON1 arylesterase enzyme activity of 2.2 ± 0.4, 15.5 ± 1.5, 30.2 ± 3.0 and 57.9 ± 5.0 U ml^?1, respectively. The results indicated that addition of rPON1 during IVM improved embryo development in a dose‐dependent manner as D7 embryo development was 22.2%, 29.4%, 32.2% and 37.0% for the treatment groups, respectively (p = 0.02). In conclusion, addition of PON1 enzyme during IVM exerted dose‐related positive effects on embryo development rates to blastocysts.  相似文献