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Raghavendra G Amachawadi Wesley A Tom Michael P Hays Samodha C Fernando Philip R Hardwidge T G Nagaraja 《Journal of animal science》2021,99(4)
Liver abscesses in feedlot cattle are polymicrobial infections. Culture-based studies have identified Fusobacterium necrophorum as the primary causative agent, but a number of other bacterial species are frequently isolated. The incidence of liver abscesses is highly variable and is affected by a number of factors, including cattle type. Holstein steers raised for beef production have a higher incidence than crossbred feedlot cattle. Tylosin is the commonly used antimicrobial feed additive to reduce the incidence of liver abscesses. The objective of this study was to utilize 16S ribosomal RNA amplicon sequence analyses to analyze the bacterial community composition of purulent material of liver abscesses of crossbred cattle (n = 24) and Holstein steers (n = 24), each fed finishing diet with or without tylosin. DNA was extracted and the V3 and V4 regions of the 16S rRNA gene were amplified, sequenced, and analyzed. The minimum, mean, and maximum sequence reads per sample were 996, 177,070, and 877,770, respectively, across all the liver abscess samples. Sequence analyses identified 5 phyla, 14 families, 98 genera, and 102 amplicon sequence variants (ASV) in the 4 treatment groups. The dominant phyla identified were Fusobacteria (52% of total reads) and Proteobacteria (33%). Of the top 25 genera identified, 17 genera were Gram negative and 8 were Gram positive. The top 3 genera, which accounted for 75% of the total reads, in the order of abundance, were Fusobacterium, Pseudomonas, and Bacteroides. The relative abundance, expressed as percent of total reads, of phyla, family, and genera did not differ (P > 0.05) between the 4 treatment groups. Generic richness and evenness, determined by Shannon–Weiner and Simpson’s diversity indices, respectively, did not differ between the groups. The UniFrac distance matrices data revealed no clustering of the ASV indicating variance between the samples within each treatment group. Co-occurrence network analysis at the genus level indicated a strong association of Fusobacterium with 15 other genera, and not all of them have been previously isolated from liver abscesses. In conclusion, the culture-independent method identified the bacterial composition of liver abscesses as predominantly Gram negative and Fusobacterium as the dominant genus, followed by Pseudomonas. The bacterial community composition did not differ between crossbred and Holstein steers fed finishing diets with or without tylosin. 相似文献
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陈冰 《吉林农业科技学院学报》2005,14(4):9-10,30
选用14日龄AA雏鸡149只,分为6组,除阴性对照外,其余试验组均用鸡支原体强毒人工接种,24h后给药,试验期为20天,综合评价试验结果:以“泰乐星”牌酒石酸泰乐菌素500mg/L组效果最好,其效果与进口产品差异不显著(P〉0.05),成活率达96%,增重率达155.9%。 相似文献
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Macrolides and lincosamides 总被引:1,自引:0,他引:1
Macrolides and lincosamides are first choice bacteriostatic antibiotics used in veterinary dermatology. The main antibiotics in these classes are erythromycin, lincomycin, clindamycin and tylosin. They are well absorbed if given orally and are able to penetrate well into infected skin. Their spectrum of action comprises bacteria commonly associated with skin infections, including staphylococci. Their main disadvantages are the rapid development of bacterial resistance and occasional gastroenteric upset, most often seen with erythromycin. More recently developed macrolides, such as azithromycin and clarithomycin, are bactericidal, have a larger spectrum of action, a longer endurance, less resistance and may be given once a day instead of two or three times daily. 相似文献
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Saurit AR Rubio M Baroni E San AM Sánchez S Boggio JC 《Veterinary research communications》2002,26(1):49-54
The pharmacokinetics of tylosin were compared in cattle (Bos taurus) and buffaloes (Bubalus bubalis). Six animals received each a single dose of 10 mg/kg of tylosin tartrate by the intramuscular route. The serum concentration (C
max) and the volume of distribution (V
d) presented significant differences between the two species. C
max was 0.40 ± 0.046 µg/ml for buffaloes and 0.64 ± 0.068 µg/ml for cattle. V
d was 1.91 ± 0.12 L/kg and 1.33 ± 0.09 L/kg for buffaloes and cattle, respectively. However, as the present study did not show considerable differences in the pharmacokinetics of tylosin in buffaloes and cattle, similar dosage regimes of this drug can be recommended for both species. 相似文献
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发酵法生产泰乐菌素过程中会产生大量药渣,因残留抗生素的存在,极大地限制了其资源化利用。本研究采用微生物法降解药渣中残留泰乐菌素。结果表明:从堆放泰乐菌素药渣附近土壤中分离筛选到1株高效降解药渣泰乐菌素的菌株,经16S rDNA鉴定为无丙二酸柠檬酸杆菌(Citrobacter amalonaticus)。该菌株适宜生长pH值为6.0~7.0、温度为30~35°C。在30°C、pH6.5条件下,将无丙二酸柠檬酸杆菌按质量比为10%的量接种于含50 mg.L-1泰乐菌素培养基中,经48 h发酵处理后,95.2%的泰乐菌素被降解。提示利用微生物法可有效降解药渣中残留泰乐菌素。 相似文献
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通过改良Hummer方法制备了氧化石墨烯(GO),通过批量平衡试验考察了其对泰乐菌素的吸附特性和机制。研究结果表明:GO对泰乐菌素的吸附在24 h可达到动态吸附平衡,吸附动力学可用拉格朗日二级动力学模型较好地拟合;吸附等温线用线性吸附模型可以较好地拟合;吸附随着p H值的升高而降低,随着离子强度的增大而减弱。 相似文献
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分别采用0.1mol/L盐酸溶液、0.05mol/L硫酸溶液、0.033mol/L磷酸溶液作稀释液测定泰乐菌素精制液化学效价,从曲线线性关系、准确度及检验结果对比方面进行分析比较。结果显示:三种溶液吸收度与浓度均呈良好的线性关系(R盐酸2=0.9997,R硫酸2=1.0000,R磷酸2=1.0000;n=5),准确度高,测定结果无明显差异,在质量控制中可以选择不同的酸稀释液进行测定。 相似文献