暹罗鳄外周血白细胞提取物抗菌活性的初步研究

用离心和细胞破碎沉淀法提取暹罗鳄外周血白细胞的抗菌活性物质,测定其对10种细菌的体外抗菌活性。结果表明：暹罗鳄外周血白细胞提取物对埃希氏大肠杆菌、海豚链球菌、多杀性巴斯德菌、温和气单胞菌、金黄色葡萄球菌、嗜水气单胞菌、副溶血弧菌、溶藻弧菌、创伤弧菌、霍乱弧菌10种细菌均有一定的抗菌效力;其中,对海豚链球菌的抗菌效力最强,抑菌圈达22．1mm;对大肠杆菌的抗菌效力次之,抑菌圈达21．7mm;对霍乱弧菌的抗菌效力较弱,抑菌圈为7mm。实验还测定了理化因子对暹罗鳄外周血白细胞提取物抗菌活性的影响,发现其具有酸溶性、EDTA敏感性和热稳定性等特点。据此特点,初步确定暹罗鳄外周血白细胞中所含的抗菌活性物质是抗菌肽。比较了暹罗鳄外周血白细胞和密西西比红耳龟、花田鸡外周血白细胞提取物的抗菌效力的强弱,发现前者对于实验所用10种细菌的抗菌效力明显强于后两者;其中,对链球菌的抗菌效力,暹罗鳄外周血白细胞提取物最强,抑菌圈达21．3mm,密西西比红耳龟外周血白细胞提取物次之,抑菌圈为5．3mm,花田鸡白细胞提取物最弱,抑菌圈为0．67mm。说明暹罗鳄外周血白细胞中存在一种或数种具有广谱、高效的抗菌活性物质。     

固体脂质纳米增强抗菌药物对胞内金黄色葡萄球菌活性的研究进展

金黄色葡萄球菌导致的乳房炎是危害奶牛养殖业最严重的疾病之一。抗菌药在胞内极易排出或失活,导致奶牛金黄色葡萄球菌乳房炎治疗效果差且容易复发。纳米粒子具有在巨噬细胞和上皮细胞等多种细胞中积累的能力,可提高药物在胞内的浓度和胞内停留时间,这使得它们可用于治疗细胞内感染。本文对固体脂质纳米抗金黄色葡萄球菌感染的研究进展进行综述,以指导和推动固体脂质纳米在治疗金黄色葡萄球菌乳腺炎方面的应用。     

动物源性食品中抗菌药残留的微生物学检测技术研究进展

抗菌药通过直接用药或用作饲料添加剂投入养殖业中,用于治疗或预防动物疾病。养殖业不当使用抗菌药,不可避免地造成抗菌药在动物源性食品中残留过量。微生物学法是最早用于抗菌药残留检测的方法,较其他检测方法而言,微生物学法操作简单、成本低、高通量,广泛应用于牛奶、畜禽组织等动物源性食品中抗菌药残留快速筛选检测,为后期的化学分析确证法节约大量成本。文章主要综述了微生物学法的发展历程及微生物学法在牛奶、可食性畜禽组织、鸡蛋、水产品、蜂蜜等动物源性食品中抗菌药残留检测的应用情况,为后续研制新微生物学法提供理论依据和实践基础,并对未来的微生物学法的发展做出展望。     

鸡毒支原体敏感药物的筛选

用泰乐菌素、强力霉素、罗红霉素、红霉素、丁胺卡那霉素、庆大霉素、环丙沙星、双氟沙星、呋喃唑酮、呋喃他酮、泰妙菌素等药物对3株鸡毒支原体进行体外抑菌试验。结果证明，它们对鸡毒支原体均有抑菌作用，但以泰乐菌素、泰妙菌素、环丙沙星和双氟沙星抑菌效果最好，达到10^-8g／L。     

Public health aspects of bacterial drug resistance in modern battery and town/village poultry in the tropics

A correlation of antibiotic use and drug resistance was found among Escherichia coli strains isolated from battery poultry in the University of Ibadan Teaching and Research Farm. All the E. coli strains from battery birds were resistant to Tetracycline, Streptomycin and Sulphonamide (Sulphafurazole) by the disc sensitivity test. In contrast, all the strains isolated from free range town and village poultry were sensitive to the range of drugs tested, while the Minimal Inhibitory Concentrations of the drugs against these free range isolates were the same as those for the control E. coli strain N.C.T.C. 10418. Ninety-eight to 100% of the strains from both battery poultry and from town/village birds were sensitive to Colistin, Chloramphenicol, Nitrofurantoin and Nalidixic Acid. Since antibiotic-resistant Escherichia coli from animal sources are known to be indistinguishable from those found in man, the indiscriminate use of antibiotics is potentially capable of giving rise to a higher incidence of intractable infection with resistant bacteria. These drug-resistant organisms may be transmitted from animal to man, and complicate the therapy of human diseases.     

Residue levels of enrofloxacin and ciprofloxacin in processed animal by‐products used in Atlantic salmon feeds and their long‐term carry‐over to the edible part of the fish

Residue levels of the antibacterials enrofloxacin and ciprofloxacin were analysed in 15 commercially relevant animal by‐products (ABPs). Enrofloxacin was detected in all ABPs, and ciprofloxacin was detected in 11 of 15 ABP samples. Feed to muscle and skin carry –over of low background enro‐ and ciprofloxacin levels were assessed by applying a simple toxicokinetic model. The muscle and skin uptake and elimination rates were established in Atlantic salmon (Salmo salar L.) fed enrofloxacin enriched diets (100 μg kg^?1 ‘low’ and 4000 μg kg^?1 ‘high’) in triplicate for 41 days followed by a 90 days depuration period. The terminal half‐lives were 17 ± 0.4 and 18 ± 0.7 days, and uptake rates were 9.3 ± 3.3 and 11 ± 3.1 (day^?1) for the ‘low’ and ‘high’ groups, respectively. Only fish fed high background levels had quantifiable levels of the metabolite ciprofloxacin with a formation of 0.25 ± 0.01% day^?1. The toxicokinetic carry‐over model predicted muscle and skin steady state levels of 1.8 μg kg^?1 when fed theoretically high enrofloxacin levels (158 μg kg^?1), which is below the EU limit of 100 μg kg^?1 for enrofloxacin in finfish food products. The antibacterial residue levels could however be detected in EU food surveillance programmes.     

中国与主要贸易国水产品中渔用抗菌药残留限量标准和管理措施对比分析

为进一步了解主要水产品贸易国抗菌药管控措施,完善中国水产品中渔用抗菌药残留限量(MRL)标准体系,提高中国水产品质量安全水平和国际竞争力。本研究比较了中国、国际食品法典委员会(CAC)、欧盟(EU)、美国和日本等国家、地区及国际组织水产品中渔用抗菌药MRL标准体系管理现状,分析中国与主要贸易国在渔用抗菌药MRL规定上的异同。结果发现,中国与上述国家、地区及国际组织在水产品中渔用抗菌药MRL数量、限量值及种类上均存在差异。其中,日本制定的MRL标准数量最多为31项,其次是欧盟有26项,中国有22项,CAC和美国制定渔用抗菌药MRL的数量较少,均为5项。针对中国目前渔用抗菌药MRL标准存在的问题,本研究提出加大渔用抗菌药的基础研究、主导或积极参与渔用抗菌药MRL制定、紧跟国际标准发展趋势、加强国际间合作交流的建议。     

新疆地区奶牛子宫内膜炎病原菌的分离鉴定及其对抗菌药的敏感性试验

通过细菌形态学和细菌生化特性,分离和鉴定了新疆地区患子宫内膜炎的21头奶牛子宫分泌物中的病原菌分别为蜡样芽孢杆菌(24.5%)、非溶血性链球菌(18.4%)、大肠杆菌(14.3%)、溶血性链球菌(10.2%)、表皮葡萄球菌(10.2%)、金黄色葡萄球菌(10.2%)、胎儿弯曲菌(10.2%)和不动杆菌等.其中革兰氏阳性菌检出率较高(73.5%).子宫内膜炎病原菌以单一菌株感染为主(47.6%).采用Kirby-Barer法测定了鉴定菌株对13种抗微生物药的体外药物敏感性.链球菌、大肠杆菌和葡萄球菌对氨苄西林不敏感,而对卡那霉素和庆大霉素敏感性较高;大肠杆菌对青霉素和氨苄西林全部耐药(100%),对四环素和多西环素耐药率较高(均为83.3%);溶血性链球菌对青霉素和四环素全部耐药,对链霉素耐药率为80%;相对而言,表皮葡萄球菌和金黄色葡萄球菌的耐药率较低;氟喹诺酮类对各种分离菌株比较敏感.     

液相色谱-电喷雾质谱/质谱法测定中兽药中的抗菌药物

采用液相色谱-电喷雾质谱/质谱法即采用梯度洗脱分离方法、电喷雾电离(ESI)、多反应监测方式(MRM),确认中兽药中滥加抗菌药物种类,测定抗菌药物的含量。结果显示:各种抗菌药物浓度为0.2 ng/mL时的信噪比均在3以上;在0.2~10 ng/mL范围内,各种抗菌药物的峰面积与浓度线性关系良好,相关系数均在0.995 0以上;回收率均在85.0%以上。该方法不仅可以确认中兽药中抗菌药物种类,而且可以检测其含量。