单胃动物肠道菌群与宿主肠道免疫系统的互作关系及可能机制

单胃动物的肠道中存在着庞大而复杂的菌群,它们与宿主肠道免疫系统协同进化。肠道细菌及其代谢产物在维持肠道稳态方面发挥着重要的作用。正常的肠道菌群能促进免疫系统发育,参与维持宿主免疫功能,协同拮抗病原菌的增殖和入侵。反过来,宿主肠道免疫系统对肠道菌群又有制约和调控作用,如对正常共生菌表现为免疫耐受,对病原菌表现为免疫排斥。一旦这种动态平衡被破坏,就会导致疾病的发生。本文综述了单胃动物肠道菌群与宿主肠道免疫系统的相互关系,并基于现有的研究结果,对其可能的互作机制做了较为系统的总结。     

Arcobacter: an emerging food-borne zoonotic pathogen,its public health concerns and advances in diagnosis and control – a comprehensive review

Arcobacter has emerged as an important food-borne zoonotic pathogen, causing sometimes serious infections in humans and animals. Newer species of Arcobacter are being incessantly emerging (presently 25 species have been identified) with novel information on the evolutionary mechanisms and genetic diversity among different Arcobacter species. These have been reported from chickens, domestic animals (cattle, pigs, sheep, horses, dogs), reptiles (lizards, snakes and chelonians), meat (poultry, pork, goat, lamb, beef, rabbit), vegetables and from humans in different countries. Arcobacters are implicated as causative agents of diarrhea, mastitis and abortion in animals, while causing bacteremia, endocarditis, peritonitis, gastroenteritis and diarrhea in humans. Three species including A. butzleri, A. cryaerophilus and A. skirrowii are predominantly associated with clinical conditions. Arcobacters are primarily transmitted through contaminated food and water sources. Identification of Arcobacter by biochemical tests is difficult and isolation remains the gold standard method. Current diagnostic advances have provided various molecular methods for efficient detection and differentiation of the Arcobacters at genus and species level. To overcome the emerging antibiotic resistance problem there is an essential need to explore the potential of novel and alternative therapies. Strengthening of the diagnostic aspects is also suggested as in most cases Arcobacters goes unnoticed and hence the exact epidemiological status remains uncertain. This review updates the current knowledge and many aspects of this important food-borne pathogen, namely etiology, evolution and emergence, genetic diversity, epidemiology, the disease in animals and humans, public health concerns, and advances in its diagnosis, prevention and control.     

硒在动植物及微生物体中的转化规律研究进展

我国低硒地区占国土总面积的72%,其中严重缺硒地区的粮食等天然食物硒含量较低,当地人因无法从食物中摄取足够硒而罹患多种疾病。因此,通过科学手段有效解决我国人体缺硒问题意义非凡。植物性食物是动物和人体碳水化合物及矿物质等营养的重要来源,植物吸收环境中的硒,并将其转化为有机态硒,之后通过食物链为人体吸收利用,这是一种安全有效的缓解人体硒摄入匮乏的途径。植物生长过程中所需的矿物质营养大多都来自于土壤,微生物作为土壤中广泛存在的一种生物,不仅在植物促生方面发挥着重要作用,而且还可通过生物活化等作用,将土壤中的硒转化为有利于植物吸收的形态,进而提高植物对硒的利用率。本文综述了目前关于动物、植物、微生物对硒转化利用规律方面的研究进展,以期为今后通过微生物介导途径,提高植物吸收转化环境硒的效率,改善动物及人体缺硒状况,进而解决缺硒地区人体健康问题提供有价值的参考信息。     

育成笼增设栖杆对转群前后鸡群适应性的影响

受育雏育成方式影响,传统笼养鸡群对立体系统适应性较差,导致严重的行为问题。该文以传统笼养育成鸡群为试验对象,探究育成期增加栖杆对鸡群转群至栖架系统前后的行为影响,改善传统笼养鸡群转至栖架系统的适应性。试验考虑加杆时间(63日龄和73日龄)和加杆位置(笼宽和笼深)2个因素。结果表明:1)加杆处理影响笼养阶段鸡群白天的行为和夜间上架情况。白天鸡群栖息行为占12.8%~21.6%,加杆10 d后的夜间栖杆使用率为75%~88%。2)加杆处理加快鸡群转群后对立体空间的适应,转群初期2个日龄处理组鸡群在爬梯栖架单元的上层平台分布比例分别为74.2%和65.6%,高于对照组的59.2%。研究结果表明,在育成笼增设栖杆可加快鸡群对立体系统的适应,且加杆时间越早,鸡群适应优势越明显。     

中国和欧美国家养殖业抗生素使用负面问题及管理政策比较

畜禽养殖中抗生素的使用无疑推动了该产业的快速发展,但也引起了其耐药性威胁公共健康和养殖业可持续发展的担忧。本文系统梳理了兽用抗生素的使用,抗生素负面问题的显现、认知和管理政策的变化,分析了中国、美国、欧盟管理政策的差异及其背后的原因。本文认为,我国在推进农业现代化进程中：应长期关注养殖业中抗生素使用可能带来的负面问题,加快生产方式的绿色转型;应提升公众对抗生素耐药性的认识,引导公众参与遏制耐药性发展的行动;应考虑我国的发展目标,吸取美国因利益集团阻挠而反应缓慢的教训,综合考虑成本和收益,发挥我国的体制优势,找到政策上的最优解;支持、推动全球抗生素管理的国际协同行动。     

精原干细胞移植在家畜生产中的应用

本文阐述了精原干细胞的分离纯化、冷冻保存、移植等一系列相关研究技术 ,同时围绕国内外最新研究进展展望了精原干细胞在家畜生产上的潜在应用     

野生动物分离菌耐药基因多重PCR检测及序列分析

调查来源于16种四川地区野生动物粪样的24株革兰氏阴性肠杆菌中氨基糖苷类抗生素四种修饰酶基因(am inoglycosides-mod ifying en-zym es,AMEs)的分布情况。应用K-B法进行常规药敏试验,采用多重PCR技术检测分离菌中四种AMEs(aphA3、aacC4、aadA、aacC2)基因并进行序列分析。药敏试验显示分离菌对链霉素的耐药率最高(8/24),对新霉素的耐药率最低(1/24%);多重PCR检测结果显示,aphA3、aa-dA、aacC2基因的检出率分别为:7/24、3/24和2/24,而所有菌株中均未检出aacC4基因;序列分析表明扩增产物与Genbank中的相应序列有很高的同源性(≥97.8%)。     

中草药提取物对水生动物常见病原菌的体外抑菌试验

采用两倍试管稀释法测定了中药提取物对水生动物常见病原菌的体外抑菌效果,试验结果表明,大黄、黄芩和板蓝根提取物对水生动物常见病原菌有较强的抑菌效果,五倍子的抑菌作用较弱。采用水煮、醇提和微波法得到的大黄、黄芩和板蓝根提取物较散剂的抑菌效果明显,但黄莲经水煮、醇提和微波提取后药效降低,五倍子的药效受提取方法影响较小。     

Brucella abortus is Prevalent in Both Humans and Animals in Bangladesh

To determine the role of different Brucella (B.) spp. in Bangladesh, 62 animal samples and 500 human sera were tested. Animal samples from cattle, goats and sheep (including milk, bull semen, vaginal swabs and placentas) were cultured for Brucella spp. Three test‐positive human sera and all animal samples were screened by Brucella genus‐specific real‐time PCR (RT‐PCR), and positive samples were then tested by IS711 RT‐PCR to detect B. abortus and B. melitensis DNA. Only B. abortus DNA was amplified from 13 human and six animal samples. This is the first report describing B. abortus as the aetiological agent of brucellosis in occupationally exposed humans in Bangladesh. Of note is failure to detect B. melitensis DNA, the species most often associated with human brucellosis worldwide. Further studies are required to explore the occurrence of Brucella melitensis in Bangladesh.