Evaluation of a Bacillus stearothermophilus tube test as a screening tool for anticoccidial residues in poultry

A Bacillus stearothermophilus var. calidolactis C953 tube test was evaluated for its ability in detecting the residue of selected anticoccidial drugs in poultry, specically sulfamethazine, furazolidone, and amprolium. Various concentrations of each drug were injected into chicken liver and kidney tissues and these tissues were tested to determine the drug detection limits for each drug. The detection limit was defined as the drug concentration at which 95% of the test results were interpreted as positive. The limits of detection in liver tissue were 0.35 µg/ml for furazolidone, 0.70 µg/ml for sulfamethazine and 7.80 µg/ml for amprolium. In kidney tissues, they were 0.30 µg/ml for furazolidone, 0.54 µg/ml for sulfamethazine, and 7.6 µg/ml for amprolium. It was concluded that this tube test could be used to screen for the residue of these three drugs in poultry.     

Isolation,Characterization, and Antimicrobial Drug Resistance Pattern of Escherichia coli Isolated from Japanese Quail and their Environment

Escherichia coli isolates were cultured from diseased Japanese quail and their environment. Of 31 E. coli isolates, 11 were cultured from heart blood of dead Japanese quail and 20 were from dead-in-shell embryos, fluff samples, and footbath and drinking water samples. All E. coli isolates were moderately positive on the Congo red binder test and 14 out of 31 isolates produced hemolysis on sheep blood agar. Twenty-seven isolates were grouped under serogroups O₄, O₉, O₃₈, O₄₂, and O₈₈, whereas 4 isolates could not be typed. Of the E. coli isolates cultured from Japanese quail infected with colibacillosis, 54.5% belonged to serogroup O₉ and the same serotype was predominant in the hatchery environment. All the E. coli isolates showed high resistance to multiple drugs with 100% resistance observed against ampicillin/cloxacillin, chloramphenicol, tetracycline, and cotrimoxazole. The highest sensitivity was observed against nitrofurantoin. This study shows that hatchery hygiene should be improved to control colibacillosis and reduce production losses. At the same time, indiscriminate use of antibiotics should be avoided as it increases the risk of development of drug-resistant strains of bacteria.     

细菌耐药颉颃剂的研究现状及应用

作者介绍了具有颉颃细菌耐药性作用的物质的研究应用进展情况，包括灭活酶抑制剂、药物渗透促进剂、外输泵抑制剂、细菌生物被膜抑制剂、抗菌药物增强剂、耐药质粒消除剂等。     

“养蚕欢二号”对家蚕病原体的消毒效果

蚕用消毒药“养蚕欢二号”是“养蚕欢”液荆的换代产品,由次氯酸盐等多种有效成分蛆成的复合消毒粉剂.用“养蚕欢二号”0.2%~0．5%的水剂或粉剂消毒蚕宣,蚕具或蚕体、蚕座,对家蚕病毒病、真菌病,微粒子病、猝倒病等防治效果迭93.3%~100%.养蚕欢二号按规定剂量使用对家蚕的发育及体质无影响.     

抑制鹿源多药耐药结核菌中药的筛选

为了筛选对鹿源多药耐药结核菌有效的中药耐药抑制剂,通过MABA法检测24种中药的水和乙醇提取物对多药耐药结核菌及标准菌H37Rv的体外抗菌效果,将筛选出的抗菌效果好的黄连醇提物和黄连水提物采用紫外分光光度法进行活性成分含量测定,同时以MABA法与标准品比较体外抗结核菌活性。结果显示,黄连、独活和侧柏叶有明显的抗结核活性,其中黄连水粗提物和乙醇粗提物效果最佳,测得它们活性成分即总生物碱含量分别为22.74%和35.23%,并显示二者与小檗碱的体外抗结核作用相同。     

不同贮藏条件对药剂处理贮藏技术效果的影响

研究了不同贮藏条件对药剂处理保持种子活力效果的影响。药剂处理种子在室温、高温或高湿条件贮藏，皆可有效保持其活力，且随着贮藏时间的延长，药剂处理与对照的差异愈明显。高温、高湿条件贮藏，各种药剂处理种子和对照处理的种子的活力均下降快，其中温度对不同处理种子的活力影响较大，不同药剂以9013保持种子活力效果最好。     

复方中药提取物在新城疫B_1株免疫中的免疫增强作用

用自制的中药提取物与新城疫Ｂ１株混合后免疫５５日龄鸡，以血凝抑制试验测定新城疫抗体效价。结果表明，５５日龄鸡的中药提取物最佳用量为１．０ｍＬ，试验组鸡ＮＤ抗体效价明显高于对照组。免疫后６０ｄ用Ｆ４８Ｅ８新城疫强毒进行攻击，试验组的保护率达到１００％，而对照组相对较低。     

基质辅助激光解吸电离飞行时间质谱在动物源细菌耐药性监测中的研究应用

细菌鉴定是细菌耐药性监测过程中的重要工作环节之一,基质辅助激光解析电离飞行时间质谱(Matrix-assisted laser desorption ionization time-off flight mass spectrometry, MALDI-TOF MS)能够高效鉴定细菌。为了快速监测五家养殖场来源的大肠杆菌和肠球菌的临床耐药特征,本研究利用MALDI-TOF MS和微量肉汤稀释法,快速鉴定临床分离的大肠杆菌和肠球菌,并对其进行耐药表型检测。结果显示,MALDI-TOF MS实现了对临床分离菌株(31株大肠杆菌和34株肠球菌)的快速鉴定;鸡源大肠杆菌和肠球菌的耐药情况最为严重,其次为羊和牛。其中,鸡源的大肠杆菌均对四环素(100%)和氨苄西林(91.67%)耐药率最高,肠球菌对苯唑西林(62.07%)耐药率较高。研究结果表明,不同动物源细菌临床耐药性表型严重程度有所不同,与此同时,MALDI-TOF MS技术可以同时实现对动物源大肠杆菌和肠球菌的快速鉴定,值得在动物源细菌耐药性检测领域推广应用。     

QuEChERS-超高效液相色谱-质谱联用法测定熊胆粉中9种苯二氮䓬类药物残留量

建立了超高效液相色谱-质谱联用法(UPLC-MS/MS)快速测定中药材熊胆粉中9种苯二氮?类药物残留的方法。样品以乙腈为提取溶剂,经萃取盐包除杂提取,采用分散式固相萃取管 (EMR-Lipid dSPE) 净化,ACQUITY BEH C18色谱柱(1.7 μm,2.1×100 mm)分离,多反应监测模式(MRM)采集数据,外标法定量。在优化的条件下,虽9种药物存在不同程度的基质效应,但不影响检测结果的准确性。方法学考察结果显示,9种苯二氮?类药物在对应的浓度范围内线性关系良好,决定系数(R²)≥0.9961,方法检出限(LOD,S/N =3)在0.06～0.71 μg/kg范围内,定量限(LOQ,S/N =10)在0.20～2.60 μg/kg范围内,3个加标水平的平均回收率在69.1%～108.0%范围内,日内RSD为1.8%～9.0%,日间RSD为2.6%～9.3%。该方法前处理操作简便、重现性好,准确度高,为熊胆粉中苯二氮?类药物残留的风险监控提供了一种有效的检测技术。     

基于纳米材料的免疫层析试纸在兽药残留检测中的应用

兽药残留是食品安全的重要影响因素,开发兽药残留检测方法是保证食品安全的重要手段。免疫层析试纸是一种操作简单、生产成本低且具有良好灵敏度的检测方法,适用于现场检测、大规模食品筛选,在兽药残留检测中具有巨大的应用价值。纳米材料可提供特殊的检测信号,是影响免疫层析试纸检测灵敏度和定量分析的关键因素。文章主要对胶体金、磁性纳米材料、量子点以及时间分辨荧光微球这几种纳米标记材料进行介绍,指出各自的优缺点及应用情况,并对该技术在兽药残留检测中的应用趋势进行展望。