Comparative genomics analysis of Raoultella planticola S25 isolated from duck in China,with florfenicol resistance

To characterize the florfenicol resistance gene and analyze the structure of the resistance gene-related sequence of an Raoultella planticola strain S25 isolated from a duck fecal sample from a farm in South China. Molecular cloning was performed to clone the resistance genes such as mdfA, floR and so on, and the minimum inhibitory concentrations (MICs) were quantified to determine the resistance levels generated by the cloned genes and the related strains. Sequencing and comparative genomics methods were used to analyze the structure of the resistance gene-related sequence. The result showed that the genome of R. planticola S25 consists of a 5.47 Mb chromosome encoding 4962 predicted coding sequence (CDS) and a 68,566 bp plasmid, pS25-68, encoding 84 ORFs. The plasmid sharing the greatest sequence identity with the floR-carrying plasmid pS25-68 is plasmid1 in Klebsiella pneumoniae strain blaNDM-1, which was isolated from a patient in Canada. The mdfA1 gene encoded on the chromosome generated resistance to florfenicol in addition to chloramphenicol. Comparative genomic analysis of the floR-related transposon-like fragment of pS25-68 showed that an approximately 3 kb sequence encoding IS91-virD2-floR-lysR was conserved and presented in the majority of the sequences (84.5 %, 169/200) collected from the database. The results of this work demonstrated that horizontal transfer of the florfenicol resistance gene floR occurred widely between the bacteria of different species and with different origins and that additional florfenicol resistance genes may be present in the bacterial population.     

硫酸头孢喹肟注射液在猪体内的生物等效性研究

为研究国产和进口硫酸头孢喹肟注射液(7.5%)在猪体内的药代动力学特征和生物等效性,采用双处理、双周期随机交叉试验设计,将20头健康三元杂交猪随机分成2组,按3mg/kg体重分别单剂量肌内注射受试制剂和参比制剂。采用超高效液相色谱-串联质谱法测定血浆中头孢喹肟的浓度,利用Win Nonlin6.3软件计算主要药动学参数,并评价两种制剂的生物等效性。结果显示,受试制剂和参比制剂的Tmax分别为2.30±0.73h和2.25±0.55h;Cmax分别为2.37±0.34μg/mL和2.45±0.36μg/mL;AUC0-t分别为26.38±2.30μg·h·mL^-1和24.86±2.19μg·h·mL^-1;AUC0-∞分别为26.74±2.34μg·h·mL^-1和25.07±2.20μg·h·mL^-1。硫酸头孢喹肟注射液受试制剂和参比制剂的AUC0-t、AUC0-∞、Cmax、Tmax均无显著性差异(P>0.05)。双单侧t检验结果显示两种制剂生物等效,临床上可相互替代。该试验可为兽医临床合理用药提供参考。     

鱼腥草注射液中非法添加甲氧氯普胺的HPLC-PDA检测方法的建立

为检测鱼腥草注射液中非法添加的甲氧氯普胺,以十八烷基键合硅胶为填充剂,0.02 mol/L磷酸溶液(用三乙胺调剂p H值至4.0)-乙腈(81:19)为流动相,流速为1.0 m L/min,波长扫描范围为200~400 nm,柱温25℃,建立了HPLC-PAD检测方法,并采用峰纯度检查和光谱相似度检查辅助对照品比对方法,对非法添加药物进行确证。结果显示,甲氧氯普胺回收率为98.8%,RSD为0.3%;线性方程为y=43542070x+36695,R2=1;检测限为6μg/m L;定量限为9μg/m L。本方法快速、灵敏、可靠,可对鱼腥草注射液中非法添加的甲氧氯普胺违禁药物进行定性和定量检测。     

不同剂型氟苯尼考对实验性鸡大肠杆菌病的疗效

以人工诱发鸡大肠杆菌病为模型,研究了不同剂型氟苯尼考的疗效。15日龄AA鸡随机分组,除健康对照组外,各组动物均肌肉注射大肠杆菌(O78)肉汤培养物诱发大肠杆菌病。氟苯尼考预混剂(100 mg/kg拌料)、可溶性粉(100 mg/L饮水)和注射剂(20mg/kg肌注)分别于攻毒前24 h、攻毒同时及攻毒后4 h给药。主要以各组动物存活数为标准评价疗效。结果表明,氟苯尼考预混剂、可溶性粉和注射剂对鸡大肠杆菌病的有效率分别为70%、90%和93.3%,而感染对照组的死亡率为73.3%,试验各组之间鸡的增重差异不显著。试验结果提示氟苯尼考饮水剂和注射剂可有效控制重症大肠杆菌病,预混剂可作为预防用药或用于治疗早期轻度感染。     

采用电位法测定氟苯尼考及其制剂的含量

用电位法测定氟苯尼考的含量。将本品用乙醇溶解,加５０％氢氧化钾溶液２０ｍｌ、加热回流４ｈ,冷却,加水１００ｍｌ稀释,用稀硝酸中和后,用加稀硝酸７．５ｍｌ,照电位滴定法,用银－玻璃电极,以硝酸银滴定液滴定。测得氟苯尼考预混剂回收率为９９．０％,ＲＳＤ为０．４１％,注射液回收率为１００．０％,ＲＳＤ为０．２８％,该法准确度高,重视性好。     

Effect of processing conditions on warpage of film insert molded parts

In order to investigate effects of injection molding conditions on viscoelastic behavior and thermal deformation of film insert molded (FIM) parts, injection molding was performed with various conditions such as injection speed, melt temperature, and packing time. It was shown that variation of the warpage was decreased monotonically with increasing injection speed and exhibited a bell-shaped curve as a function of melt temperature. Warpage variation was not affected by the packing time significantly and the proportional relationship between warpage of the film insert molded part and shrinkage of the injection molded part without film was observed. The FIM specimens produced with unannealed films showed the warpage reversal phenomenon (WRP) during annealing and the magnitude of reversed warpage was affected significantly by the injection parameters and the extent of thermal shrinkage of the unannealed film. Warpage of the FIM specimen was predicted by three dimensional numerical flow and stress analyses and the predicted values showed a good agreement with the experimental results.     

Detection of the floR Gene in a Diversity of Florfenicol Resistant Gram‐Negative Bacilli from Freshwater Salmon Farms in Chile

Florfenicol is an important antibiotic in veterinary medicine that is used extensively in aquaculture, including salmon farming in Chile. We analysed a set of 119 florfenicol‐resistant Gram‐negative bacilli from seven freshwater Chilean salmon farms for the molecular determinants involved in the florfenicol resistance. Ninety‐seven of these strains were glucose non‐fermenting bacilli, mainly belonging to the Pseudomonas genus, whereas 22 strains were glucose‐fermenters. The floR gene was detected in 26 strains (21.8%) that had been isolated from three of the seven salmon farms. Most of the floR‐carrying strains were glucose fermenters (21 strains), and most of the floR‐carrying strains were also resistant to streptomycin, chloramphenicol and oxytetracycline. The minimum inhibitory concentrations against florfenicol were assessed in the presence and absence of the efflux pump inhibitor Phe‐Arg‐β‐naphthylamide (MC‐207,110). There was evidence that in the majority of non‐fermenting bacteria (82 strains), florfenicol resistance was at least partially mediated by non‐specific efflux pump systems. Given the diversity of antibiotic resistance patterns observed in this study in the floR‐positive isolates, a single antibiotic has the potential to co‐select for a diversity of resistances. For this reason, human health as well as animal health can potentially be impacted by the use of antibiotics in aquaculture. To assess this potential risk, future studies should focus on the ability of different antibiotics used in aquatic environments to co‐select for multiple resistances, the molecular basis of this diversity of resistance, and whether the genes conferring resistance can be transferred to other bacteria, including those of human health concern.     

痰热清注射液对社区获得性肺炎临床疗效及血清PCT水平的影响

目的 探讨痰热清注射液对社区获得性肺炎临床疗效及血清降钙素原（PCT）水平的影响。方法 选择116例社区获得性肺炎患者为研究对象,依据随机数字表法分为试验组和对照组各58例。对照组采用抗感染、化痰、对症等常规治疗,试验组在此基础上联合痰热清注射液治疗,观察两组患者的体温、临床症状、PCT水平变化。结果 试验组总有效率为94.8%,对照组为81.0%,试验组总有效率明显高于对照组,差异有统计学意义（P<0.05）;治疗后两组血清PCT水平均降低（P<0.05）,但试验组较对照组降低明显,差异有统计学意义（P<0.05）。结论 痰热清注射液能显著改善社区获得性肺炎患者临床症状,提高临床疗效,下调血清PCT浓度,且无明显不良反应发生。     

采用反相高效液相色谱法测定注射用六茜素含量

采用反相高效液相色谱法测定注射用六茜素的含量。结果表明,该方法灵敏度高、选择性好、操作简便、结果准确。六茜素在60-140μg/m l范围内呈良好线性关系Y=0.008 6X＋0.004 16（r=0.999 9）。     

流动注射分析的原理和应用

本文介绍了流动注射分析的基本原理和装置,该法的优点,综述了近十年在我国的研究进展。