Clinical Breakpoint of Apramycin to Swine Salmonella and Its Effect on Ileum Flora

The purpose of this study was to establish the clinical breakpoint (CBP) of apramycin (APR) against Salmonella in swine and evaluate its effect on intestinal microbiota. The CBP was established based on three cutoff values of wild-type cutoff value (CO_WT), pharmacokinetic-pharmadynamic (PK/PD) cutoff value (CO_PD) and clinical cutoff value (CO_CL). The effect of the optimized dose regimen based on ex vivo PK/PD study. The evolution of the ileum flora was determined by the 16rRNA gene sequencing and bioinformatics. This study firstly established the CO_WT, CO_PD in ileum, and CO_CL of APR against swine Salmonella, the value of these cutoffs were 32 µg/mL, 32 µg/mL and 8 µg/mL, respectively. According to the guiding principle of the Clinical Laboratory Standards Institute (CLSI), the final CBP in ileum was 32 µg/mL. Our results revealed the main evolution route in the composition of ileum microbiota of diarrheic piglets treated by APR. The change of the abundances of Bacteroidetes and Euryarchaeota was the most obvious during the evolution process. Methanobrevibacter, Prevotella, S24-7 and Ruminococcaceae were obtained as the highest abundance genus. The abundance of Methanobrevibacter increased significantly when APR treatment carried and decreased in cure and withdrawal period groups. The abundance of Prevotella in the tested groups was significantly lower than that in the healthy group. A decreased of abundance in S24-7 was observed after Salmonella infection and increased slightly after cure. Ruminococcaceae increased significantly after Salmonella infection and decreased significantly after APR treatment. In addition, the genera of Methanobrevibacter and Prevotella were defined as the key node. Valine, leucine and isoleucine biosynthesis, D-Glutamine and D-glutamate metabolism, D-Alanine metabolism, Peptidoglycan and amino acids biosynthesis were the top five Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in the ileum microbiota of piglets during the Salmonella infection and APR treatment process. Our study extended the understanding of dynamic shift of gut microbes during diarrheic piglets treated by APR.     

Effects of dietary supplementation with antimicrobial peptide‐P5 on growth performance,apparent total tract digestibility,faecal and intestinal microflora and intestinal morphology of weanling pigs

BACKGROUND: The increase in drug‐resistant bacteria and the ban on antibiotic growth promoters worldwide make the search for novel means of preventing bacterial infection and promoting growth performance imperative. In this sense, antimicrobial peptides are thought to be ideal candidates owing to their antimicrobial properties, broad spectrum of activity and low propensity for development of bacterial resistance. The aim of the present study was to investigate the effect of dietary supplementation with antimicrobial peptide‐P5 (AMP‐P5) on weanling pig nutrition. RESULTS: A total of 240 weanling pigs were allotted to four treatments on the basis of initial body weight. There were four replicates in each treatment, with 15 pigs per replicate. Dietary treatments were negative control (NC, basal diet without antimicrobial), positive control (PC, basal diet + 1.5 g kg^?1 apramycin), basal diet with 40 mg kg^?1 AMP‐P5 (P5‐40) and basal diet with 60 mg kg^?1 AMP‐P5 (P5‐60). Pigs fed the PC or P5‐60 diet showed improved (P < 0.05) overall growth performance, apparent total tract digestibility of dry matter, crude protein and gross energy and reduced (P < 0.05) faecal and intestinal coliforms compared with pigs fed the NC diet. CONCLUSION: The results obtained in this study indicate that dietary supplementation with 60 mg kg^?1 AMP‐P5 has the potential to improve the growth performance and apparent total tract digestibility of nutrients and reduce coliforms in weanling pigs. © 2012 Society of Chemical Industry     

液相色谱-串联质谱法检测动物组织中阿布拉霉素

目的 建立动物源食品中阿布拉霉素的LC-MS/MS检测方法。方法 待测样品中的阿布拉霉素用5%的三氯乙酸溶液提取, 经MCX固相萃取柱净化、浓缩、定容后采用液相色谱-串联质谱法在正离子模式下检测。结果 该方法在0~5 mg/L范围内有良好的线性关系, 相关系数r>0.995, 在不同基质中, 不同的添加水平下该方法的平均回收率范围在80.9%~101%, 相对标准偏差为1.17%~12.60%; 定量下限为0.030 mg/kg。结论 此方法灵敏度高、准确、重现性好, 适用于动物组织中阿布拉霉素残留量的检测。     

安普霉素生产废水毒性去除与产酸发酵预处理

应用连续流搅拌槽式反应器(CSTR)对安普霉素废水进行产酸发酵和去毒处理,在进水COD质量浓度为5 000~8 000 mg/L,HRT为8 h的条件下,对安普霉素生产废水的COD去除率平均为21.53%,而HRT为12 h时平均为17.62%.HRT为8 h和12 h对悬浮物(SS)的平均去除率分别为56.78%和53.05%;对氨氮的平均去除率分别为11.05%和6.39%.经产酸发酵处理过的安普霉素生产废水,其毒性被去除,BOD5/COD(B/C)从处理前的0.35分别提高到0.42以上,去除单位重量COD的甲烷产量达到164 mL/g以上,可采用产甲烷相进行更进一步的有效处理.