Pharmacokinetics and Bioavailability of Florfenicol Following Intravenous,Intramuscular and Oral Administrations in Rabbits

This study examined the disposition kinetics and bioavailability of florfenicol after intravenous (i.v.), intramuscular (i.m.) and oral administration to rabbits at a dose of 30 mg/kg BW. Serial blood samples were collected through an indwelling catheter intermittently for 24 h for various routes. Plasma antibacterial concentrations were determined using a microbiological assay method with Bacillus subtilis ATCC 6633 as a reference organism. Plasma concentration-time data generated in the present study were analysed by non-compartmental methods based on statistical moment theory. Following i.v. administration, the overall elimination half-life (t1/2beta) was 1.54 h, mean residence time (MRT) was 1.69 h, mean volume of distribution at steady-state (Vdss) was 0.57 L/kg, and total body clearance (Cltot) was 0.34 L/kg/h. After i.m. and oral dosing, the terminal part of the curve should correspond to the absorption phase, instead of to the elimination phase, with terminal half-lives of 3.01 and 2.57 h, respectively. The mean absorption time (MAT) was 2.65 h for i.m. and 2.01 h for oral administration. Elimination rate constants differed with i.v., i.m. and oral administrations, suggesting a flip-flop situation. The observed mean peak plasma concentrations (Cmax obs) were 21.65 and 15.14 microg/ml achieved at a post-injection time (Tmax obs) of 0.5 h following i.m. and oral dosing, respectively. The absolute systemic availabilities were 88.25% and 50.79%, respectively, and the extent of plasma protein binding percent was 11.65%.     

两种微生物制剂对猪粪堆肥的效果

为解决猪粪出路,应用两种微生物制剂进行了堆肥试验研究。结果表明,两种微生物制剂对堆肥发酵是有利的。Ａ菌对有机质的分解率约为５０％,比对照快,Ｂ菌分解率只有２５％左右,比对照慢;Ａ菌对腐殖质的分解速率与有机质一致,Ｂ菌的分解速率比对照低一成左右而有利于腐殖质的保存;Ａ菌肥的总氮量比对照少一成左右,Ｂ菌肥比对照略好;ＮＨ４＿Ｎ,Ａ菌肥与对照一致,Ｂ菌肥比对照多一成左右;猪粪堆制后,ＮＨ４＿Ｎ占全氮的比例,两个加菌处理都比对照高;全磷量,Ｂ菌肥与对照相近,Ａ菌肥比对照少一成左右。盆栽青菜,Ａ菌肥比对照增产一成以上。     

Development of a new dispenser for microbiological control agents and evaluation of dissemination by bumblebees in greenhouse strawberries

BACKGROUND: To date, in modern agriculture, biological control strategies are increasingly becoming the preferred pest management approach. However, the success of microbiological control agents (MCAs) largely depends on efficient dissemination into the crop. The pollinator‐and‐vector technology employs pollinating insects like bees for a better dissemination. In this study, a new dispenser for bumblebee workers of Bombus terrestris L. was developed. Binab‐T‐vector and Prestop‐Mix were used as two typical MCA products for dissemination. RESULTS: In a first series of experiments in the laboratory for optimisation, the newly developed dispenser was a two‐way type dispenser, 20 cm long, with two rectangular compartments and different entrance and exit holes. In addition, the amounts of MCA loaded on the workers were 10 times higher with the new dispenser as compared with the side‐by‐side passageway (SSP) dispenser. Typically, the highest amounts were recovered from the thorax and legs of the workers. In a second series of experiments under greenhouse conditions with the use of queen‐right B. terrestris hives, successful dissemination in strawberry flowers was obtained at different distances from the hive (0–8 m, 8–18 m and 18–21 m), and the workers inoculated the first, second and third flowers that were consecutively visited. In addition, the new dispenser caused no adverse effects on worker foraging intensity, whereas a dramatic reduction was scored with an SSP dispenser. Finally, the data suggested that it is necessary to refill the newly developed dispenser at 3 day intervals. CONCLUSIONS: The results demonstrated that, with the use of the newly developed dispenser, bumblebee workers carried high amounts of MCA, and this resulted in a successful dissemination of MCA into strawberry flowers. Copyright © 2010 Society of Chemical Industry     

Reflecting on the Recent Publisher's Report

Research was conducted to determine the effects of potassium sorbate applications (0, 1, 3, and 5% w/v) on the shelf life of pearl mullet (?nci Kefali; Chalcalburnus tarichi) fillets packaged with vacuum. Fillets kept at 4 ± 1°C were subjected to microbiological (total aerobic mesophilic bacteria, psychrotrophic bacteria, lactic acid bacteria, Enterobacteriaceae, molds, and yeasts) and chemical (pH, thiobarbituric acid—TBA, total volatile base nitrogen—TVB-N, water activity, and biogenic amines) analyses on certain days (0, 3, 6, 9, and 12 days) of storage. It was determined that potassium sorbate had effects on total aerobic mesophilic bacteria, psychrotrophic bacteria, Enterobacteriaceae, mold-yeast counts, TVB-N values, phenylethylamine, putrescine, tryptamine, and pH of fillets at a significant (p < 0.01) degree. Retarded bacterial growth was observed as the antimicrobial effect increased with the degree of its concentrations. Storage time had significant (p < 0.01) effects on bacteria count, TBA, TVB-N values, and biogenic amines; all of which were increased by longer storage. It was concluded that application of potassium sorbate, especially at a 5% level, and vacuum packaging helps cold stored fillets maintain their biogenic amines and microbiological and chemical qualities longer.     

恩拉霉素微生物检定法的研究

以枯草芽孢杆菌为检定菌,检定培养基Ⅰ号为试验用培养基,采用双碟法进行恩拉霉素样品测定。通过浸提溶液组成、浸提时间、检定菌浓度考察,优化了检定条件。在此基础上,确立了恩拉霉素浓度的对数值与抑菌圈直径的线性范围,并对所建立的微生物检定法进行准确度、最小检出限等考察。结果表明,采用丙酮浸提液B、浸提恩拉霉素样品80 min,恩拉霉素浸提较完全。在检定菌浓度10⁶ 个/mL的条件下,恩拉霉素浓度在0.56~35.79 U/mL之间,其浓度的对数值与相应的抑菌圈直径呈直线相关,相关系数r为0.9960。将建立的恩拉霉素微生物检定法用于恩拉霉素样品测定,回收率为95.90%,相对标准偏差(RSD)为1.95%。本方法可用于含恩拉霉素的样品测定。     

美国国家公园入选标准和指令性文件体系

论述了土壤学科基础理论研究和测试方法的重大进展 ,森林土壤学科国内外研究现状及未来发展趋势。指出依据森林土壤功能与其组成、结构、性质一致性的原理 ,揭示并调控不同林分类型土壤功能的动态演化规律 ,合理地利用森林土壤资源、永续经营是森林土壤学科未来的研究方向。     

二次杀菌方式对红肠在冷藏过程中微生物及理化性质影响的研究

为研究常压杀菌方式对红肠在冷藏过程中理化及微生物指标变化的影响,将加工好的红肠真空包装后分为3组,分别为对照组(CK)、一次杀菌组和二次杀菌组。将3组红肠置于0~4℃条件下冷藏9周,分别在0、3、5、7、9周取样分析各组的理化指标(pH、硫代巴比妥酸反应物(TBARs)值、水分迁移变化、亚硝酸盐残留量)和微生物指标(细菌总数、肠杆菌科菌、假单胞菌、乳酸菌)的变化。结果表明:随着冷藏时间的延长,各组红肠样品中微生物数量、TBARs值和pH均有不同程度的升高趋势,亚硝酸盐残留量呈降低趋势;与CK组相比,各冷藏时间点的一次杀菌组和二次杀菌组红肠中的细菌总数、肠杆菌科菌、假单胞菌、乳酸菌数量和TBARs值、亚硝酸盐残留量均显著低于CK组(P<0.05),且二次杀菌组显著低于一次杀菌组(P<0.05);从水分迁移的变化来看,二次杀菌的红肠,初始横向驰豫时间T₂₂由CK组的37.649 ms升至41.408 ms,说明不易流动水向右发生了微弱的迁移现象,肌肉蛋白对水分约束力略有下降。由此说明,常压杀菌尤其是经过二次杀菌的红肠,其微生物指标、脂肪氧化程度、亚硝酸盐残留量显著降低,呈现出显著的优势,提高了红肠的食用安全性。     

生物淋滤去除农用污泥中重金属的效果及工艺

污水处理厂污泥中的重金属含量高是污泥农用的主要障碍。该文针对天津污水处理厂污泥含铜量高的特性,分别以硫酸亚铁和硫粉作为培养基进行生物淋滤对比试验,前者对铜的去除率远远高于后者。以硫酸亚铁作为培养基,研究了投配比、接种污泥量、pH值和温度对污泥中重金属去除效果的影响。结果表明,在硫酸亚铁投配比为10 g/L、污泥接种量为20%、温度为28℃、淋滤时间为4 d时,污泥中重金属Cu、Pb、Cr、Ni、Zn和Cd的去除率分别为89%、38%、61%、76%、72%和57%,其相应残余量分别为116、62.5、98、22、174、1.1 mg/kg。在7～28℃范围内,温度越高,氧化亚铁硫杆菌活性越高,生物淋滤时间越短;28℃和35℃下氧化亚铁硫杆菌活性基本相同。以硫酸亚铁为培养基淋滤处理后污泥中重金属的含量可满足《农用污泥中污染物控制标准》(GB4284-1984)。     

Potential Use of a Poultry Manure Digestate as a Biofertiliser: Evaluation of Soil Properties and Lactuca sativa Growth

Anaerobic digestion is a process that is widely used for the treatment of organic wastes. The digestate can be used as a soil amendment or crop fertiliser. The aims of our work were to evaluate 1) the physicochemical composition and pathogen content in a digestate from poultry manure, according to international regulations, and 2) the effect of its soil application on the major chemical and biological soil properties and on the growth of Lactuca sativa. The experiment consisted of two groups of pots(with and without crop). Treatments applied to each group were as follows: low and high doses of digestate and inorganic fertiliser, and no application(control)(low dose: 70 kg nitrogen(N) ha~(-1) and 21 kg phosphorus(P) ha~(-1); high dose: 210 kg N ha~(-1) and 63 kg P ha~(-1)). Soil samples were taken 7 and 34 d(harvest) after treatment applications. Heavy metal and pathogen contents in the digestate were below the upper limit values. Despite the high pH and electrical conductivity values of the digestate, both soil parameters presented acceptable values for crop growth. Although there were no initial increases in total inorganic N and available P in soil with digestate application, an increase in the fresh weight of crop was observed with the high dose application. This is probably associated with the slow nutrient release from the digestate during the development of the crop. Changes in the microbial community were temporary and occurred at the initial sampling stage of the experiment.     

江西地区鸭疫里氏杆菌微生物学特性的研究

从江西省鸭鹅中分离到 6 0株鸭疫里氏杆菌 ,采用凝集试验和琼脂扩散试验对其血清型进行了鉴定 ,结果表明江西存在 5个血清型的鸭疫里氏杆菌 (2、JX1、JX2、JX3、JX4型 ) ,2、JX1、JX2型为目前江西地区主要流行的血清型。 80 %以上分离株对青霉素、痢特灵、氨苄青霉毒和氯霉素高度敏感 ,对阿米卡星、庆大霉素和链霉素耐药。不同血清型鸭疫里氏杆菌的培养特性较为一致 ,但部分生化特性存在较大差异