Antipenicillinase in the serum of dairy cows

Serum from dairy cows was tested for inhibitory effect on penicillinase from a penicillin-resistant Staphylococcus aureus strain of mastitic origin. Among cows with subclinical mastitis caused by penicillin-resistant S. aureus there was a significantly higher frequency of individuals with penicillinajse-inhibiting serum than among healthy cows. Among the subclinical cases, a foregoing penicillin treatment of clinical mastitis appeared to increase the serum antipenicillinase activity.     

Benzathine Penicillin G and Procaine Penicillin G in Piglets: Comparison of Intramuscular and Subcutaneous Injection

The disposition of penicillin G in piglets is described after intramuscular or subcutaneous injection of depot preparations. The piglets were injected with 33 000 IU/kg or 100 000 IU/kg benzathine + procaine penicillin G intramuscularly or subcutaneously, or 100 000 IU/kg procaine penicillin G intramuscularly or subcutaneously. Intramuscular injection of benzathine + procaine penicillin resulted in higher maximum concentration in plasma (C_max) than did subcutaneous injection. The mean residence time (MRT) of penicillin G was longer when the drugs were injected subcutaneously rather than intramuscularly. The plasma concentration versus time profiles of the subcutaneous injections of benzathine + procaine penicillin revealed secondary peaks, possibly reflecting a certain degree of inflammation at the injection site.     

双黄连口服液联合青霉素G对金黄色葡萄球菌的体外抗菌作用研究

用美国临床实验室标准化委员会(NCCLS)介绍的方法,分别测得双黄连口服液和青霉素G对金黄色葡萄球菌的最低抑菌浓度(Minimum inhibitory concentration,MIC);使用棋盘联合药敏试验法,以部分抑菌浓度(Fractional inhibitory concentration,FIC)指数为指标,观察双黄连口服液和青霉素G联用对金黄色葡萄球菌的抗菌作用.结果表明,双黄连口服液对金黄色葡萄球菌的MIC是46.88 mg/mL(稀释度1:32);青霉素G对金黄色葡萄球菌的MIC是0.25 U/mL;双黄连口服液和青霉素G联用对金黄色葡萄球菌的FIC指数是0.125.双黄连口服液联用青霉素G对金黄色葡萄球菌联合药敏结果呈协同作用.     

高效液相色谱紫外法同时检测鸡蛋中5种青霉素类药物残留的研究

试验旨在建立一种同时检测鸡蛋中5种青霉素类药物残留的高效液相色谱紫外检测法。鸡蛋经乙腈提取、正己烷脱脂、旋转蒸发浓缩和衍生化后,采用高效液相色谱法分离检测。结果显示,氨苄西林（ampicillin,AMP）、氯唑西林（cloxacillin,CLO）、苯唑西林（oxacillin,OXA）、阿莫西林（amoxicillin,AMO）及普鲁卡因青霉素（penicillins G procaine,PRO）在10~1 000 μg/kg呈良好线性关系,R²>0.999;检测限为1.5 μg/kg（S/N=3）,定量限为5.0 μg/kg（S/N=10）,添加平均回收率为62.04%~93.13%,相对标准偏差为3.91%~13.69%,批内相对标准偏差为3.98%~14.71%,批间相对标准偏差为4.26%~12.71%。表明本试验建立的高效液相色谱紫外法重复性和灵敏度较高,适用于鸡蛋中的5种青霉素类药物残留检测。     

牛奶中青霉素快速检测的研究

研究了Benedict试剂与牛奶中青霉素的反应。实验表明,不能用Benedict试剂检测利乐包装商品牛奶中的青霉素含量。     

An improved microbiological procedure for detection of streptomycin residues in milk and animal tissues.

A method is described which allows detection of 0.025 µg streptomycin sulfate per ml. This represents an improvement of sensitivity by 8 times when compared with the currently used method. By adding penicillin to the assay medium in subinhibitory concentrations, a synergistic effect of streptomycin and penicillin is exerted towards the test organism, Bacillus subtilis, resulting in an increased sensitivity to streptomycin.     

An integrated experimental and physiologically based pharmacokinetic modeling study of penicillin G in heavy sows

Penicillin G is widely used in food‐producing animals at extralabel doses and is one of the most frequently identified violative drug residues in animal‐derived food products. In this study, the plasma pharmacokinetics and tissue residue depletion of penicillin G in heavy sows after repeated intramuscular administrations at label (6.5 mg/kg) and 5 × label (32.5 mg/kg) doses were determined. Plasma, urine, and environmental samples were tested as potential antemortem markers for penicillin G residues. The collected new data and other available data from the literature were used to develop a population physiologically based pharmacokinetic (PBPK) model for penicillin G in heavy sows. The results showed that antemortem testing of urine provided potential correlation with tissue residue levels. Based on the United States Department of Agriculture Food Safety and Inspection Service action limit of 25 ng/g, the model estimated a withdrawal interval of 38 days for penicillin G in heavy sows after 3 repeated intramuscular injections at 5 × label dose. This study improves our understanding of penicillin G pharmacokinetics and tissue residue depletion in heavy sows and provides a tool to predict proper withdrawal intervals after extralabel use of penicillin G in heavy sows, thereby helping safety assessment of sow‐derived meat products.     

牛奶中青霉素残留的微生物学检测方法研究进展

本文主要介绍了目前国外常用的牛奶中青霉素残留的微生物学检测方法。微生物学检测方法可分为微生物抑制法、微生物受体法和酶比色法。并对微生物学检测方法中存在的影响因素进行了分析。     

絮凝剂在青霉素酰化酶提取中的应用

选用一种阳离子絮凝剂甲壳素对E .coli10 8发酵液进行处理 ,并改进渗透压提取青霉素酰化酶的方法 ,使酶活的提取率达到了 96 .4 % ,降低了能耗 ,酶的比活力达到 6 .4 9× 10 -6mol·min-1·mg-1。