有望减少弯曲杆菌

肉鸡生产者在应对沙门氏菌疾病上已经取得很大的成功,正如英国食品标准局Kathryn Callaghan所解释的那样:现在肉鸡生产者的工作重点已经转移至预防舍饲肉鸡的弯曲杆菌感染上。     

家禽及其产品中弯曲杆菌和沙门氏菌的分子分型技术

分子分型提供了一种准确判断病原体的来源和传播路径的策略，有助于控制来源于家禽和家禽产品病原体的污染，而且分子分型还有助于鉴定存在于家禽中的毒力决定基因，从而确定一些能导致人类疾病的菌系。尽管毒力决定因子在大肠杆菌和肠道沙门氏菌已经被鉴定，而且分子分型和毒力检测已经应用多年，但毒力决定基因尚未在弯曲杆菌中得以鉴定，但已经发现了可能的毒力基因，如cdt基因，     

弯曲杆菌病

近10年来,人类的弯曲杆菌感染大量增加。自从弯曲杆菌感染被认识之初,家禽就被认为是人类感染的重要来源。必须进行通力合作以便找出解决这一问题的有效方法。     

鸡空肠弯曲杆菌病的诊治

弯曲杆菌病是由弯曲杆菌引起的家禽、野禽、哺乳动物及人类共患的一种重要传染病。空肠弯曲杆菌作为人类肠炎的病因,仅次于沙门氏菌和痢疾杆菌。禽类弯曲杆菌感染十分普遍,鸡弯曲杆菌病又称鸡弧     

预防食品中沙门氏菌和弯曲杆菌的研究进展

沙门氏菌和弯曲杆菌在世界范围内是非常重要的动物传染病病原体，是细菌性胃肠炎最常见的病因与人类传染病有关的所有媒介物中，最重要的是被污染的禽肉和禽蛋. 要有效地减少人类感染沙门氏菌和弯曲杆菌，就应对人类食品生产链的一些关键点进行控制基于众多原因，阻断细菌侵入动物宿主体内具有相当重要的战略意义、对于家禽来说，病菌不断地在宿主体内繁殖，并且可以存活几个月以上，这种早期的繁殖可很大程度地增加屠宰期间痛原体的传播机会，并且使这个问题很难解决、另外，食用动物体内的沙门氏菌的某些血清型具有侵入性，可污染其内部、例如，在过去20年中，沙门氏杆菌污染的鸡蛋已经成为主要的全球性公共卫生问题，其中沙门氏杆菌是世界绝大多数地区引起人沙门氏菌病的主要诱因除此之外，一些沙门氏杆菌血清型不仅能引起人类疾病，而且还是饲养动物重要的病原体,采取措施防止沙门氏菌在一些宿主体内定植，也会通过减少动物感染的方式直接改善动物福利. 现在已经确定了多种弯曲杆菌感染的媒介物，虽然很难准确地确定家禽的作用占到多大的比例，但是大家普遍认同被污染的禽肉是最重要的媒介物（Hams等，1986）因为胴体被污染的比例相当高，但为了逛免引起争论，我们只假设40％的病例是由被污染的家禽引起的（Jorgensen等，2002）因此，无论对于公众健康还是经济效益来说，减少弯曲杆菌在鸡肉中的定植都非常重要.     

禽类弯曲杆菌

弯曲杆菌及其同属菌群是脊椎动物和某些非脊椎动物口腔及肠道内的共生菌,这种特性导致控制家禽中弯曲杆菌污染问题复杂化。本文详细讨论了弯曲杆菌的系统发育,基因组学及其生理学,深入揭示了这些微生物是如何通过进化,进而占据肠道的有利环境,提出只有深刻了解它们的生理学,才能制定有效的控制方案。     

弯曲杆菌及其引起的疾病

弯曲杆菌(Campylobacter)又称甘必罗菌,近年来作为引起人的肠炎的食物中毒菌受到各国的注目。为查明弯曲杆菌与人及动物的关系,许多科学工作者进行了广泛地调查和研究,从人及多种动物分离出弯曲杆菌,并且发现来源于牛、鸡、犬、猫等动物的菌株血清型与人的有共同性。表明,     

预防食品中沙门氏菌和弯曲杆菌的研究进展

（接《新饲料》2007年射8期21页） 国际家禽业界建立了一种很好的预防沙门氏菌的措施，就是在肉鸡生产中使用混合细菌培养物，这种方法通常被称为“竞争性排斥”。已经有研究试图培育能有效抑制弯曲杆菌的制剂，但尚未取得实质性进展（Aho等，1992；Line等，1997）。另一种可能是，经检测呈弯曲杆菌阴性的肉雏鸡肠道的微生物区系对空肠弯曲杆菌具有天然的抗性（Humphrey等，1989）。     

新西兰:家禽业者成功控制弯曲杆菌

新西兰家禽产业联合会(PIANZ)称,2007～2010年间,新西兰家禽产业中弯曲杆菌的检测感染率下降了25%。自2008年4月开始,新西兰食品安全局便启动了《弯曲杆菌指标管理计划》,用以监     

The challenge for the next generation of feline calicivirus vaccines

Feline calicivirus (FCV) has been shown to evolve within individual cats and in the environment of colonies. This evolution and the diversity it creates has important clinical implications, not only for the disease in cats, but also for attempts to control disease by vaccination. Generally speaking, existing vaccines appear to be very effective at controlling the majority of clinical disease. However, some concerns remain including a failure to induce sterilising immunity, occasional vaccine breakdowns, and for live vaccines, occasional vaccine-induced disease. Key areas for future vaccine development include monitoring and broadening the cross-reactivity of vaccine immunity to field viruses, especially the recently evolved highly virulent strains, and attempting to reduce/eliminate field virus shedding by vaccinated cats.     

Comparative efficacy of ten commercial Campylobacter fetus vaccines in the pregnant guinea pig: challenge with Campylobacter fetus serotype A.

Efficacy of ten commercial Campylobacter fetus vaccines was tested in pregnant guinea pigs and compared with that of an experimental vaccine prepared from the challenge-exposure strain. If the first lot of vaccine failed to protect 50% of the guinea pigs, one or two additional lots of that vaccine were purchased and retested. Three vaccines for cattle, evaluated, as the most effective of those tested, protected 62%, 72%, and 89% of the guinea pigs from abortion; the experimental vaccine protected 98%. The two vaccines for sheep protected 50% and 61% of the guinea pigs from abortion. With the other five vaccines produced for immunizing cattle, protection was from 0% to 36%, with the exception of one lot of a vaccine that protected 74%. Blood infection was found at necropsy in only 6% of the guinea pigs given vaccines that protected 50% or more from abortion, but was found in 66% of those given vaccines that protected less than 50%. Similarly, tissue infection was found at necropsy in only 18% of the guinea pigs given vaccines that protected more than 50%, but was found in 91% of those given vaccines that protected less than 50% from abortion. Oil-emulsion adjuvants appeared to enhance protection from abortion and infection. Nodules persisted at the injection site in most of the guinea pigs immunized with vaccines containing oil-emulsion adjuvants, but rarely persisted in guinea pigs given aqueous-phase adjuvant vaccines. Comparison of efficacy of the vaccines in guinea pigs with efficacy in sheep and cattle remains to be made.     

Campylobacter jejuni, Campylobacter coli, and cytolethal distending toxin genes in laying hens

As no data are available on the prevalence of cytolethal distending toxin (cdt) genes carried by Campylobacter spp. in laying hens, this study was conducted with the aim to evaluate the prevalence of both Campylobacter spp. and cdt genes in 1680 laying hens from four different farms. The samples were analyzed by culture methods and by polymerase chain reaction. Campylobacter spp. were isolated from 1097/1680 cloacal swabs. Among the isolates, 913 were identified as Campylobacter jejuni whereas 345 were identified as Campylobacter coli. All isolates carried cdt genes. The results presented here confirm the very common occurrence of C. jejuni and C. coli in laying hens and underline that the cdt genes may also be frequently present in both C. jejuni and C. coli isolates from laying hens.     

Campylobacter jejuni strains of human and chicken origin are invasive in chickens after oral challenge

The aim of the study was to evaluate the colonizing ability and the invasive capacity of selected Campylobacter jejuni strains of importance for the epidemiology of C jejuni in Danish broiler chickens. Four C. jejuni strains were selected for experimental colonization studies in day-old and 14-day-old chickens hatched from specific pathogen free (SPF) eggs. Of the four C. jejuni strains tested, three were Penner heat-stable serotype 2, flaA type 1/1, the most common type found among broilers and human cases in Denmark. The fourth strain was Penner heat-stable serotype 19, which has been shown to be associated with the Guillain Barré Syndrome (GBS) in humans. The minimum dose for establishing colonization in the day-old chickens was approximately 2 cfu, whereas two- to threefold higher doses were required for establishing colonization in the 14-day-old chickens. Two of the C. jejuni strains were shown to be invasive in orally challenged chickens as well as in three different human epithelial cell lines.     

Campylobacter

Species within the genus, Campylobacter, have emerged over the last three decades as significant clinical pathogens, particularly of human public health concern, where the majority of acute bacterial enteritis in the Western world is due to these organisms. Of particular concern are the species, C. jejuni and C. coli, which are responsible for most of these gastrointestinal-related infections. Although these organisms have already emerged as causative agents of zoonoses, several aspects of their epidemiology and pathophysiology are only beginning to emerge. Trends in increasing antibiotic resistance are beginning to emerge with oral antibiotics, which may be the drug of choice for when it is necessary to intervene chemotherapeutically. This review wishes to examine (i) emerging clinical aspects of the disease, such as Guillain Barre syndrome (GBS), (ii) the association between these organisms and poultry as a natural host, (iii) environmental aspects of Campylobacter epidemiology, (iv) the emergence of atypical campylobacters (v) emerging trends in antibiotic resistance, (vi) adoption of modern methods for the detection of campylobacters.     

"养鸡生产中沙门氏菌病的预防与控制策略"专栏(四)沙门氏杆菌和弯曲杆菌在家禽群体中的动态变化特征

难道我们不想掌控自身命运吗?虽然这是-个很广博的问题,但如果你在考虑幼龄肉鸡群沙门氏菌感染这个特定话题以及考虑它与人食源性疾病可能的关系时,这个问题就具有特殊的意义.出席美国国家家禽改良计划(the National Poultry Improvement Plan,NPIP)第40届年会(两年一次)的大多数代表,在投票是否采用美国肉鸡扩繁群肠炎沙门氏菌监测方案时,对该特殊问题给出了肯定回答.     

防止禽流感的再次大流行

禽流感使养禽业,尤其是禽类健康研究人员非常忙碌。媒体的关注,以及日益增加的爆发次数,要求我们采取更多的行动重点防止禽流感的再次大流行及其带来的恐慌。美国的研究人员正试图通过共同努力以阻止该病的发生。     

Campylobacter infection and Campylobacter excretion in turkeys

Five turkey poults at an age of 27 days were infected with Campylobacter jejuni strain. Additional five poults were infected by contact. Turkeys infected by contact and artificially were necropsied 1 and 3 months later, respectively. The histological examination of the liver revealed degenerative changes in contact birds and a proliferation of the connective tissue and bile-ducts in two of the oral infected poults. Campylobacter spp. were excreted daily during the first two weeks and afterwards with interruptions of several days. The excretion lasted until the end of the experiment between day 86 and 98. The excretion period, which is prolonged compared with that of chickens may be of particular importance under aspects of epizootiology and food hygiene.