产气荚膜梭菌检测方法研究进展

产气荚膜梭菌是革兰氏阳性厌氧菌,广泛存在于环境中,包括污染的水、食物和土壤中,当机体胃肠道菌群紊乱或受到气温骤降等应激反应时,产气荚膜梭菌可大量繁殖并产生毒素,引起人和动物气性坏疽、食物中毒、肠炎、肠毒血症等多种疾病,严重危害人和动物的健康,不仅给养殖户造成严重的经济损失,影响畜牧业的发展,而且对公共卫生安全造成威胁。产气荚膜梭菌分型比较复杂,特异性诊断是防治该病的重要环节,因此需要快捷、高效和准确的鉴定和分型。目前,关于产气荚膜梭菌的主要检测方法有微生物学检测法、免疫学检测法以及分子生物学检测法。本文主要对产气荚膜梭菌的检测法进行总结,为产气荚膜梭菌检测方法的研究方向提供科学依据。     

羊毒素型产气荚膜梭菌临床症状及病理变化

产气荚膜梭菌可引起绵羊、山羊和其他动物的肠道疾病,不同毒素型的产气荚膜梭菌可引起羊肠毒血症、羊猝狙、羊肠毒血症等。产气荚膜梭菌对宿主通常具有破坏性影响,根据发病羊群的以往病史、临床病变和剖检病例变化是羊产气荚膜梭菌病初步诊断的基础,而该病的确诊还需实验室检测后方可确认。确定羊产气荚膜梭菌病最广泛被接受的方法是从患有典型临床症状的病羊肠内容物检测到产气荚膜梭菌毒素。此外,大脑的组织病例理学检查对于由D型产气荚膜梭菌引起的疾病诊断中十分有用。本文对各种类型产气荚膜梭菌引起疾病的临床病变和组织病变进行综述。     

动物源产气荚膜梭菌耐药性研究进展

细菌耐药性是21世纪人类面临的重大公共卫生安全问题之一。产气荚膜梭菌作为一种重要的人兽共患病原菌，能引起人和动物食物中毒、气性坏疽、坏死性肠炎等多种疾病。随着临床抗菌药物的广泛使用，其耐药性也在不断发展，严重威胁着公共卫生安全和养殖业的健康发展。本文将从产气荚膜梭菌近十年来的耐药性流行情况、耐药机制及耐药基因传播机制两个方面进行归纳总结，旨在为产气荚膜梭菌耐药性的防控提供理论依据。     

羊产气荚膜梭菌病诊治

羊产气荚膜梭菌病是由产气荚膜梭菌(旧名产气荚膜杆菌)引起的一种急性毒血症.产气荚膜梭菌在自然界分布广泛,土壤、污水、粪便、饲料以及人畜的胃肠道内等都有分布,在一定的条件下该菌可引发严重疾病[1].该病在绵羊多呈急性和最急性经过,发病不分性别和年龄,一年四季都可发生,但春秋季和阴雨天气发病较多.发病率高,可呈地方性流行.     

奶牛场产气荚膜梭菌病的诊断报告

奶牛产气荚膜梭菌病又称为猝死症。引起该病的原因较多,但一般认为是由牛A型产气荚膜梭菌(又称产气荚膜杆菌)引起的。临床上以病牛突然死亡,消化道和实质器官出血为特征。大、小奶牛都可发病,但以犊牛、孕牛和高产牛多发,死亡率70%～100%。一年四季均可发病,但以夏秋两季高发。目前该病已广泛分布于世界各地,呈全球流行态势,严重危害各国畜禽业发展,对奶牛生产也造成了很大危害。笔者现将一奶牛场发生奶牛产气荚膜梭菌病     

蛋鸡坏死性肠炎的诊治

蛋鸡坏死性肠炎是由魏氏梭菌引起的一种条件性传染病,病原为A型或C型的产气荚膜梭菌。产气荚膜梭菌常存在于粪便、土壤、灰尘及污染的饲料、饮水、垫料中,只要环境条件适宜,就可诱发本病。今年6~8月期间,笔者连续5次在临床上碰到该病,现将该病的发病情况、临床症状、病理变化及治疗措施综述如下。     

某小型肉牛屠宰场产气荚膜梭菌定量风险评估

为探明小型屠宰场生产牛肉中产气荚膜梭菌的消费风险及其生产链中的关键风险防控点,以北京市某小型肉牛屠宰场不同样品的产气荚膜梭菌污染监测数据和调研数据为基础,构建了牛肉中产气荚膜梭菌定量风险评估模型,并通过@Risk软件模拟运行分析。通过模型模拟的屠宰后单头牛胴体表面产气荚膜梭菌污染量90%的可能分布在102.00～563.00 CFU,平均值为280.84 CFU,而实际监测数据拟合为291.17 CFU,说明模型可信。根据屠宰过程中各环节的模拟数据,构建了牛胴体表面携带产气荚膜梭菌消长变化图,发现产气荚膜梭菌携带量从剥皮后的122.31 CFU/头上升至屠宰后的280.00 CFU/头,屠宰环节携带量为0.11 CFU/100 g,而销售环节升至4.95 CFU/100 g。通过模型对各变量参数进行敏感性分析,发现胴体表面产气荚膜梭菌污染对牛肉产气荚膜梭菌污染的风险贡献最大(R=0.69),其次是空气中的带菌量,而销售环节100 g牛肉携带产气荚膜梭菌的风险主要与从屠宰到销售过程中牛肉带菌量变化有关(R=0.96)。可见,屠宰过程中肉牛的本底携带、空气中带菌量以及储运销售过程中的交叉污染是牛肉中产气荚膜梭菌污染的关键控制点。结合剂量-反应关系和膳食数据,模型评估的本屠宰场生产牛肉中产气荚膜梭菌引发的感染风险每年不足1例,风险极低。本研究构建了小型肉牛屠宰场屠宰过程中产气荚膜梭菌定量风险评估模型,可为牛屠宰场产气荚膜梭菌污染的风险管理提供参考。     

牛猝死病的调查与防治研究

1995年3月对平凉地区东五县,43个乡(镇)流行的一种不明原因,引起牛只大量急性死亡的疾病进行了流行病学调查、病理解剖学、细菌学检验、肠内容物毒素检验及产气荚膜梭菌A、B、C及D型多价菌苗的诊断性预防注射,初步确定该病为产气荚膜梭菌引起的出血性肠毒血症。在发病区免疫注射2700余头牛,接种3个月后,经回访调查凡接种菌苗的牛未曾发病死亡,而未注射菌苗牛只继续呈散发性发病死亡,初步试验结果表明,我们研制的产气荚膜梭菌苗对防治该病的发生是安全有效的。     

青岛地区兔源产气荚膜梭菌的分离鉴定及遗传多样性分析

兔的梭菌性肠炎是由产气荚膜梭菌感染引起的严重危害养兔业的一种疾病,为了更好地控制此病,本研究调查了青岛地区规模化兔场爆发此病时产气荚膜梭菌的毒素型及遗传多样性。2010年11月-2012年5月期间,采集青岛地区规模化养兔场疑似产气荚膜梭菌感染兔的肝脏进行产气荚膜梭菌的分离鉴定,采用Multiple—PCR方法对分离菌株进行毒素型分析,应用ERIC-PCR方法分析分离菌株的遗传多样性。共分离到25株产气荚膜梭菌,其中A型24株（96％）,C型1株（4％）。用ERIC—PCR方法将25株分离株分于9个聚类中,其中V型为主要流行型。结果表明：青岛地区规模化兔场中产气荚膜梭菌流行的毒素型主要为A型,且具有多种基因亚型,其中V型为主要流行型。此结果为该地区兔产气荚膜梭菌病的免疫和微生态防治提供了重要的参考依据。     

蛋鸡坏死性肠炎的诊治

蛋鸡坏死性肠炎是由魏氏梭菌引起的一种条件性传染病，病原为A型或C型的产气荚膜梭菌。产气荚膜梭菌常存在于粪便、土壤、灰尘及污染的饲料、饮水、垫料中，只要环境条件适宜，就可诱发本病。今年6～8月期间，笔者连续5次在临床上碰到该病，现将该病的发病情况、临床症状、病理变化及治疗措施综述如下。     

隐孢子虫病的流行现状

隐孢子虫病是由隐孢子虫(Cryptosporidium)寄生于人类、家养动物及多种野生动物胃肠道引起的一种严重的人畜共患胃肠疾病。该病不但威胁人类健康,亦严重影响畜牧业发展。近年来随着研究的深入,隐孢子虫的流行表现出许多新的特点,危害远远超出了人们的估计。这些特点主要表现在：感染家畜,增加人类感染风险;与动物其他病原混合感染危害加重;感染野生动物,具有自然疫源性;感染海洋和水生动物,造成水体污染;经水源和食物传播引起人类群体感染;暴发感染对人群危害严重。深入开展隐孢子虫病流行病及防控研究对提高公共卫生水平具有重要意义。     

Spread of resistant bacteria and resistance genes from animals to humans--the public health consequences

The paper reviews the lines of evidence which link the use of antimicrobial drugs for food animals with the emergence of antimicrobial drug resistance in bacteria pathogenic to humans, with a particular focus on the public health aspects. Deductions from the epidemiology of food-borne infections, ecological studies, outbreak investigations, typing studies and direct epidemiological observations show that resistant bacteria are transferred from food animals to man. In addition to transfer in the food chain, exchange of mobile genetic elements among commensal and pathogenic bacteria contributes to the emergence of drug resistance. There is growing evidence that this has measurable consequences for human public health. One consequence is increased transmission supported by unrelated use of anti-microbials in humans. Other consequences are related to reduced efficacy of early empirical treatment, limitations in the choices for treatment after confirmed microbiological diagnosis, and finally a possible coselection of virulence traits. Recent epidemiological studies have measured these consequences in terms of excess mortality associated with resistance, increased duration of illness, and increased risk of invasive illness or hospitalization following infections with resistant Salmonella.     

动物源性食品安全问题与对策

随着现代化经济的快速发展,人们生活水平的不断提高,对动物源性食品的需求也越来越多,然而,动物源性食品安全问题也日益显露无疑,严重威胁着公共卫生安全及人体健康,已造成严重后果,引起了各方面的高度关注。本文系统分析认为,饲料的污染、养殖场生态环境的严重污染、养殖生产中滥用抗生素、使用违禁添加剂、动物源性食品加工和储藏过程中违规或超量使用食品添加剂、检出手段落后、法律法规体系不健全、管理部门多、政务分割是产生动物源性食品安全事故的根源。针对目前的现状,提出了动物源性食品安全的控制对策是加强宣传,提高人们对畜产品安全重要性的认识,发展生态畜牧业模式,完善疫病防控体系,强化动物疫病防控意识,加强监管,确保动物源性食品源头的质量安全、强化监管职责,确保畜产品的屠宰加工质量、加强动物疫病监测体系建设、建立与国际标准接轨的奶业标准体系,各职能部门应切实承担起这项工作,加强此方面的监管力度,以保障人体健康,维护社会安定。     

Evidence of an association between use of anti-microbial agents in food animals and anti-microbial resistance among bacteria isolated from humans and the human health consequences of such resistance

Several lines of evidence indicate that the use of anti-microbial agents in food animals is associated with anti-microbial resistance among bacteria isolated from humans. The use of anti-microbial agents in food animals is most clearly associated with anti-microbial resistance among Salmonella and Campylobacter isolated from humans, but also appears likely among enterococci, Escherichia coli and other bacteria. Evidence is also accumulating that the anti-microbial resistance among bacteria isolated from humans could be the result of using anti-microbial agents in food animals and is leading to human health consequences. These human health consequences include: (i) infections that would not have otherwise occurred and (ii) increased frequency of treatment failures and increased severity of infection. Increased severity of infection includes longer duration of illness, increased frequency of bloodstream infections, increased hospitalization and increased mortality. Continued work and research efforts will provide more evidence to explain the connection between the use of anti-microbial agents in food animals and anti-microbial-resistant infections in humans. One particular focus, which would solidify this connection, is to understand the factors that dictate spread of resistance determinants, especially resistant genes. With continued efforts on the part of the medical, veterinary and public health community, such research may contribute to more precise guidelines on the use of anti-microbials in food animals.     

动物疫病与人类健康

人类健康和生命安全正面临动物疫源性疾病、动物性食品安全、动物源性耐药菌、兽药生态毒理作用、养殖污染、生物剂及生物恐怖袭击的威胁,尤其是人畜共患病的增加,动物疫病已上升为影响公共安全的一个重大社会问题。针对我国现行公共卫生体系存在的不足,应建立动物医学、动物科学与人医学一体化的公共卫生体系和长效运行机制。     

一个值得高度关注的问题——动物源细菌耐药性

由于动物源细菌耐药性关乎到人类健康,使得畜禽疾病防控和公共卫生安全日益受到全世界的普遍关注。本文就动物源细菌耐药性的危害、我国动物源细菌的耐药性状况、发展趋势及应对策略进行了综述,以期对我国开展动物源细菌耐药性检测和制定预防对策提供参考。     

Adhesion of bacteria to the cecal mucosal surface of conventional and germ-free chickens infected with Eimeria tenella.

When Salmonella typhimurium and Clostridium perfringens were tested in conventional chickens, larger numbers of S typhimurium and C perfringens adhered to Eimeria tenella-infected ceca than to uninfected ceca. In germ-free chickens, S typhimurium and C perfringens adhered to the E tenella-infected cecal mucosa more than to the uninfected cecal mucosa, but fewer Bacteroides vulgatus and Bifidobacterium thermophilum adhered to the E tenella-infected ceca than to the uninfected ceca. Many bacteria adhered to the lesions caused by E tenella as observed by scanning electron microscopy. On the basis of our findings, we suggest that infection with E tenella upsets the balance of competitive adherence of bacteria, allowing more colonization of S typhimurium and C perfringens.     

牛羊口蹄疫疫苗免疫副反应产生的因素及防治策略

近年来,我国的动物疫病防控工作取得了重要的成效,动物源型食品安全水平得到明显的提高,公共卫生安全保障水平进一步提高。但口蹄疫依然在全球多个区域发生和流行,严重威胁着现代畜牧业健康发展,为有效遏制该病的发生与流行,免疫接种疫苗是预防和消灭该病最有效、经济、关键的策略。但是基层动物防疫员在给牛羊注射口蹄疫疫苗时偶尔有免疫副反应现象发生,给部分养殖户造成了一定的经济损失,也给重大动物疫病防控工作带来一定的负面影响和阻力。本文分析了牛羊口蹄疫疫苗免疫副反应的产生原因、临床症状、救治及预防措施,给基层一线从事动物防疫工作人员提供参考。     

Interaction between probiotic lactic acid bacteria and canine enteric pathogens: a risk factor for intestinal Enterococcus faecium colonization?

Selected probiotic lactic acid bacteria (LAB) have been shown to elicit positive health effects particularly in humans. Competitive exclusion of pathogens is one of the most important beneficial health claims of probiotic bacteria. The effect of probiotic LAB on competitive exclusion of pathogens has been demonstrated in humans, chicken and pigs. In this study we evaluated the ability of certain LAB strains (Lactobacillus rhamnosus GG, Bifidobacterium lactis Bb12, Lactobacillus pentosus UK1A, L. pentosus SK2A, Enterococcus faecium M74 and E. faecium SF273) to inhibit the adhesion of selected canine and zoonotic pathogens (Staphylococcus intermedius, Salmonella Typhimurium ATCC 14028, Clostridium perfringens and Campylobacter jejuni) to immobilised mucus isolated from canine jejunal chyme in vitro. Adhesion of C. perfringens was reduced significantly by all tested LAB strains, between 53.7 and 79.1% of the control without LAB, the LAB of canine origin yielding the best reduction. The adhesion of S. Typhimurium and S. intermedius were not significantly altered by any of the LAB included in the study. Both enterococci tested significantly enhanced the adhesion of C. jejuni, to 134.6 and 205.5% of the control without LAB. E. faecium may thus favor the adhesion and colonization of C. jejuni in the dog's intestine, making it a potential carrier and possibly a source for human infection. Enhanced C. jejuni adhesion is a new potential risk factor of enterococci. Our results further emphasize the importance of safety guidelines to be established for the probiotics intended for animal use.     

家兔“流行性腹胀病”的病因和防治研究初报

对近3年四川发生的兔腹胀病的流行特点、临床症状、剖解病理变化、病因和防治进行了初步的研究。结果,该兔腹胀病主要引起断奶后至3月龄左右的兔发病,发病率一般在30％～60％,死亡率达90％以上．具有一定传染性和区域流行性。病兔出现明显腹胀,胃膨胀,胃内充满食物或水样稀薄的内容物,部分胃粘膜有黑色溃疡斑点,结肠内多充满白色胶冻样半透明状物。从69例病死兔中,分离到38株魏氏梭菌（55％）、13株大肠杆菌和2株沙门氏杆菌,大多数菌株都有致病力。添加霉菌毒素吸附剂或抗球虫药物不能有效控制该病。而使用恩拉霉素和蒽诺沙星可在1周内控制该病的发生。初步的研究结果表明：该病可能是一种细菌性传染病,其病原菌有可能是以魏氏梭菌为主,还有大肠杆菌、沙门氏茵等细菌,为单一或混合感染所致。