Sulfonamide residues in eggs.

In two series of experiments lasting 3 days each, laying hens were medicated with sulfonamides via the drinking water. In the first experiment 8 laying hens were given sulfaquinoxaline (SQ) at a dose rate of 400 mg/l, while in the second trial 16 laying hens received a 3:5:5 sulfonamide mixture containing sulfaquinoxaline (SQ), sulfadimidine (SDI) and sulfamerazine (SMN), at a dose of 390 mg/l. According to the water consumption data, the hens' daily sulfonamide intake was 53.6 and 56.9 mg/kg body mass, respectively. Eggs laid during and in the first 10 days after the treatment were collected and assayed for sulfonamide residues by spectrophotometry. The detection limit of the method was 0.16 mg/l and the recovery percentage was between 70 and 80%. Sulfonamide was found to appear already in eggs laid after the first day of treatment. The absorption half-life of the drug was 0.4-0.6 day in the egg-white and 0.93-1.08 day in the egg-yolk. Peak drug level in the egg-white was measured on the last day of medication, while in the egg-yolk within 3 days after the end of treatment. The residue measured in the yolk was 13-16% of that found in the egg-white. Acetylated sulfonamide could be measured in the yolk for 3 days after the treatment: its level reached 15%. On the basis of the elimination rate, complete elimination of sulfonamides requires at least 5.2-7.4 days. Therefore, observance of the generally accepted withdrawal time of 10 days is indispensable.     

磺胺类药物在动物性食品中的残留与检测

磺胺类药物是一类广谱抗茵药,临床上主要用于预防和治疗细菌感染性疾病,还常作为饲料添加剂在动物生产中长期应用.然而,磺胺药会引起人过敏性反应,且可能有致癌性.因此,磺胺类药物的不合理使用,使其在动物性食品中残留引起生态环境污染和人类健康危害的潜在威胁已倍受关注.因此,研究出一种操作简便、快速、灵敏的磺胺类药物残留检测方法,对于畜产品的安全具有实际意义.酶联免疫吸附法(ELISA)作为一种免疫学检测技术不仅具有上述优点,而且准确性好、特异性强、检测成本低,还可用于大批量样品的检测.而单抗在试剂的标准化及抗体的大量供应上明显优于多抗,所以单克隆抗体技术的应用在药残检测上是主要的发展方向.     

A single‐nucleotide polymorphism in the canine cytochrome b5 reductase (CYB5R3) gene is associated with sulfonamide hypersensitivity and is overrepresented in Doberman Pinschers

Canine sulfonamide hypersensitivity (HS) has been associated with a variant in the cytochrome b₅ reductase gene (CYB5R3 729A>G), which encodes a drug‐detoxifying enzyme. Study objectives were to determine variant allele frequency in Doberman Pinschers (DOBE), a breed which may be predisposed to sulfonamide HS, and to characterize the effects of CYB5R3 729G on gene expression and function. CYB5R3 729A>G allele frequencies were compared between DOBE (n = 24) vs. non‐Doberman (non‐DOBE; n = 60) dogs. CYB5R3mRNA expression, protein expression, and reduction of sulfamethoxazole hydroxylamine were compared between banked canine liver samples of 729AA vs. GG genotype. The 729G allele was overrepresented in DOBE (1.00) vs. non‐DOBE dogs (0.567, p < .0001). mRNA and protein expressions as well as cyt b₅ reductase activity were similar between livers of AA and GG genotype. All Doberman Pinschers in this study were homozygous for CYB5R3 729G, which could contribute to this breed's apparent predisposition to sulfonamide HS. However, CYB5R3 729G does not alter sulfamethoxazole detoxification capacity, so a direct role could not be demonstrated. It is possible that this marker is linked to another contributing variant.     

磺胺类药物广谱性多克隆抗体的制备

基于磺胺类药物(Sulfonamides,SAs)公共母环(对氨基苯磺酰胺)结构,合成了两种具有该结构的半抗原∶2-(对氨基苯磺酸氨基)-4-噻唑乙酸(TS)和对氨基苯磺酰胺基苯甲酸(SS).采用碳二亚胺法合成了免疫原和包被原,分别免疫10只新西兰大白兔,制备广谱性磺胺类药物抗体.应用间接竞争酶联免疫吸附分析(ELISA)检测血清的灵敏度和特异性,发现所有兔子对TS-BSA和SS-BSA均产生较高效价和特异性.其中SS-1号和TS-6号兔的血清灵敏度最好,效价分别为1∶80 000和1∶160 000,对10种磺胺类药物均有不同程度的识别能力.SS-BSA组IC50为257.9～6 590.9 ng/mL,而TS-BSA组IC50为12.9～586.1 ng/mL.结果表明,具有磺胺母环结构的半抗原TS和SS,可以应用于广谱性磺胺类抗体的制备.通过10只兔子免疫试验证明,应用SS获得的血清具有较高的簇特异性、相似的亲和性,优于TS.     

Sulfonamide and toltrazuril therapy of experimental turkey coccidiosis

Following experimental infection of caged turkeys with a mixed oocyst suspension of E. meleagrimitis, E. adenoeides and E. gallopavonis, the efficacy of sulfachlorpyrazine, sulfaquinoxaline + pyrimethamine, sulfaquinoxaline + diaveridine, and toltrazuril was investigated based on clinical and parasitological parameters. Infected turkeys developed severe clinical symptoms. Only weak symptoms were observed in those groups which were treated with the sulfa- and sulfa-DHFR-inhibitors. The toltrazuril-treated group remained free of clinical symptoms. At the 8th day after infection, the clinical lesions coincided with the intensity of the gut lesions together with parasitological findings based on microscopical examination of mucosal smears. The same coincidence was observed for parameters such as oocyst excretion and body weight development.     

应用TTC法检测牛奶中磺胺类残留的试验

利用嗜热链球菌为菌种检验牛奶中抗菌素残留的氯化三苯基四氮唑法（TTC法），是我国的国家标准方法。本研究尝试利用TTC法检验鲜乳中磺胺类药物残留，结果发现检验的灵敏度很低，检出限高于国外对其残留控制标准。说明TTC法不能用于精确检验鲜乳中磺胺类药物残留是否超过最高限量（0．1mg／kg）。     

Sulfonamide residues in pork: past, present, and future

The Food Safety and Inspection Service (FSIS) of the U. S. Department of Agriculture (USDA) has been involved for a number of years with the problem of sulfonamide residues in pork. In the 1970s, concern was raised regarding the use of sulfonamides when food safety criteria used for premarketing approval of new animal drugs and the safety data base for sulfonamides were found to be inadequate. Regulatory analytical methods for monitoring sulfonamides were developed and put to use by FSIS. With educational efforts by government and industry, by 1980 it was thought that the problem was being solved. In the 1980s, however, the sulfonamide violation rate began to increase; the USDA strengthened its educational programs, developed a rapid test for sulfonamides and pursued regulatory initiatives. By 1987 sulfonamide violations in liver tissue (i.e., greater than .1 ppm) had declined to 3.8%; however, new toxicological information associating sulfamethazine with the development of follicular cell adenomas of the thyroid gland in rats and mice led the FSIS to begin an enhanced sulfamethazine control program in the spring of 1988. The FSIS believes that production quality assurance is the key to prevention. The Agency's initiatives toward this end are designed both to encourage industry accountability and to provide disincentives for violators. The current approaches to the sulfonamide problem hold the clear promise of a satisfactory solution.     

Association of Hepatic Necrosis With Trimethoprim Sulfonamide Administration in 4 Dogs

Hepatic necrosis in association with trimethoprim-sulfonamide (TMS) combination therapy was diagnosed in 4 dogs based on history, clinical presentation, and examination of histopathologic specimens collected postmortem. Duration of TMS therapy prior to onset of clinical signs ranged from 4 to 30 days. The dose of TMS ranged from 18 mg/kg to 53 mg/kg bid. Despite supportive medical therapy, all dogs died or were euthanized due to hepatic failure. This report highlights the potential for hepatotoxicity during TMS therapy. Duration of therapy, type of TMS combination, and dose did not appear related to the development of toxicity. The low number of dogs affected suggests an idiosyncratic drug reaction.     

An Improved Bacteriological Method for the Detection of Sulfonamide Residues in Food

The addition of trimethoprim to Mueller-Hinton medium was found to improve the sensitivity of test bacteria towards sulfonamides by 20—50 times. Depending on the test bacteria used, the optimal concentrations of trimethoprim added to the medium are 1 μg per ml (Micrococcus luteus), 0.25 μg per ml (Bacillus stearothermophilus var. calidolactis) and 0.1 μg per ml (Bacillus megaterium). Using Micrococcus luteus or Bacillus megaterium a concentration of 0.25 μg sulfanilamide per ml may be detected, and 0.1 μg per ml may be detected when Bacillus stearothermophilus var. calidolactis is used.     

犊牛磺胺中毒的病理形态学观察

为了解犊牛磺胺中毒的病理形态学变化特点,对2头因磺胺中毒而死亡的犊牛进行了详细的病理学研究.结果表明,犊牛磺胺中毒的病理性损伤主要发生于肾脏和肝脏.宏观检查可见,肾脏肿胀,色泽变淡,皮质增宽,肾盂有多量豆腐渣样物质.肝脏肿胀,淡橘红色,质地脆易碎.微观检查可见,近曲小管上皮细胞肿胀,核浓缩,染色不良,大量上皮细胞脱落....     

固相萃取-超高效液相色谱法同时测定猪肉中22种磺胺类药物残留

为探索一次性检测猪肉中多种磺胺类药物残留的检测方法,建立了同时测定猪肉中22种磺胺类药物残留的固相萃取-超高效液相色谱方法。样品用3%乙酸乙腈提取,MCX固相萃取柱净化,水和甲醇淋洗,5%氨化甲醇洗脱,氮气吹至近干,0.1%甲酸-乙腈(9:1,V/V)溶液复溶,二极管阵列检测器270 nm检测。结果显示:该方法对22种磺胺类药物检测的线性关系良好(R2 0.999),定量限为2.5～10.0μg/kg,检测限为1.0～4.0μg/kg;各药物平均回收率为83.2%～96.6%,批内和批间变异系数分别为1.1%～3.5%和3.6%～13.4%。结果表明,该方法灵敏度高、重复性好、成本低廉,且操作简单、快速,可用于猪肉样品中多种磺胺类药物残留的同时检测。     

不同地区猪源大肠埃希菌磺胺类药物耐药性研究

对不同地区猪源大肠埃希菌磺胺药物耐药性进行系统性调查研究.对从山东、内蒙古、山西分离到的161株猪源大肠埃希菌测定磺胺药物对其最低抑菌浓度(MIC值),结果表明大肠埃希菌对磺胺药物高度耐药,对磺胺异恶唑(SF)和新诺明(SMZ)的耐药率分别为91.30%和90.06%.同时根据GenBank上已有的二氢叶酸合成酶基因S...     

磺胺类药物多克隆抗体的制备与ELISA检测方法的初步研究

模拟磺胺母核结构合成了3种人工免疫原,免疫新西兰白兔,用间接竞争ELISA方法监测免疫效果。选择抑制效果较好的2组多抗血清建立磺胺类药的ELISA检测方法,绘制竞争标准曲线,并进行添加回收试验。结果表明：A组多克隆抗体对6种常用磺胺药SMD、SMM、SMZ、SDM、SDM、SD的IC10分别为0．010、0．046、0．010、0．100、0．067、0．019μg／mL,低于最高残留限量（0．10μg／mL）;C组多克隆抗体对SMD、SMM、SMZ、SDM、SQ、SD、磺胺氯哒嗪、磺胺氯吡嗪的IC10分别为0．0091、0．051、0．058、0．088、0．020、0．010、0．014、0．011μg／mL,亦低于最高残留限量。2组多克隆抗体对磺胺药的回收率为54．5％～111．8％和54．2％～130．3％,变异系数为3．6％～10．9％和3．7％～5．9％。     

超高效液相色谱-串联质谱法同时检测鸡蛋中5种磺胺类药物和甲氧苄啶残留量

建立超高效液相色谱-串联质谱法(Ultrahigh-performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)同时测定鸡蛋中5种磺胺类药物(磺胺甲恶唑、磺胺二甲嘧啶、磺胺间甲氧嘧啶、磺胺喹噁啉、磺胺二甲氧嘧啶)和甲氧苄啶的残留量的方法。样品经乙腈提取2次, 95%乙腈溶液进行溶解后,过Alumina B Cartridges柱,30%乙腈洗脱,滤膜过滤后滤液用于超高效液相色谱-串联质谱仪测定,外标基质标准曲线法定量。在0.5～100μg/kg的浓度范围内5种磺胺类药物和甲氧苄啶色谱峰面积与浓度呈良好线性相关,相关系数均大于0.99;方法检测限0.5μg/kg、定量限为1.0μg/kg;鸡蛋样品中5种磺胺类药物和甲氧苄啶在1.0～100.0μg/kg添加水平内的平均回收率在66.3%～97.5%之间,批内、批间相对标准偏差在1.4%～11.4%之间。该方法回收率满足残留检测要求,且方法的重现性良好,满足国内外兽药残留相关法规规定。     

大肠杆菌磺胺类抗生素耐药基因二重PCR技术的建立

为建立一种一次性检测多个磺胺类抗生素耐药基因的检测方法,用磺胺类抗生素耐药大肠杆菌作为受试生物,根据磺胺类抗生素耐药基因Sul1和dfrA1设计一对引物进行二重PCR检测。结果发现:本方法能有效检测出大肠杆菌Sul1和dfrA1两种磺胺类抗生素耐药基因,检出限为4.5 cfu/μL,对于Sul1和dfrA1两种磺胺类抗生素耐药基因具有较强的检出特异性。此方法对检测大肠杆菌磺胺类抗生素耐药基因提供了有力的技术支撑。     

固相萃取-高效液相色谱法同时检测奶牛粪污中5种磺胺类抗生素

建立的固相萃取-高效液相色谱法具有灵敏度高、检测限低的特点,可同时定量检测奶牛粪污中磺胺嘧啶、磺胺二甲嘧啶、磺胺间甲氧嘧啶、磺胺甲恶唑、磺胺喹噁啉的残留。采用C18色谱柱(500 mm×4.6 nm, 5μm),以0.3%的乙酸-乙腈溶液为流动相,在流速1.0 mL/min、检测波长270 nm、柱温30℃条件下,5种抗生素均能达到基线分离;3倍信噪比下,5种抗生素的检出限均为20μg/kg。在加标浓度50μg/kg条件下,奶牛粪污样品经前处理、MCX固相萃取小柱富集净化后,五种磺胺类抗生素回收率达到75%～80%,相对标准偏差为2.8%～3.9%。此方法检测了某规模化奶牛场粪污中磺胺类抗生素残留,结果显示,磺胺嘧啶的浓度范围在45～50μg/kg,其他抗生素无检出。