产气荚膜梭菌主要外毒素最新研究进展

产气荚膜梭菌是一种重要的人兽共患病的病原体,可引起人的食物中毒和抗生素相关腹泻.近年来,对产气荚膜梭菌的主要外毒素研究取得了重大进展.本文综述了产气荚膜梭菌主要外毒素的组成、结构、理化性质、作用机理、检测及分子遗传学等方面的研究进展.     

猪A型产气荚膜梭菌病研究

家畜A型产气荚膜梭菌病是我省首先发现的一种多种家畜共患的传染病。目前全国许多省市都有发生。由于该病往往没有任何前驱症状，突然发病死亡，在没有确定该病病原之前，人们通常称之家畜“猝死症”。我省该病最初见于1985年河南周口市某县，当时呈零星散发，患病家畜以犊牛和仔猪为主。近几年来，仔猪对该病的感染率呈上升趋势，为了有效控制该病，笔者曾系统参与了我省A型产气荚膜梭菌病的研究，现将其研究结果报告于后。     

产气荚膜梭菌唾液酸酶研究进展

产气荚膜梭菌是重要的人畜共患病原菌,可导致许多类型动物坏死性肠炎和肠毒素血症。产气荚膜梭菌产生多种毒素以及许多酶,该菌可产生3种唾液酸酶,包括1个内分泌唾液酸酶NanH与2个外分泌唾液酸酶NanI和NanJ。产气荚膜梭菌唾液酸酶表达调控系统(VirS/VirR 2组分信号转导系统、RevR调控系统、ReeS调控系统、NanR调控系统、VR-RNA调控系统)通过增加毒素的活性以及增强产气荚膜梭菌对肠细胞的黏附等方式在产气荚膜梭菌发病机理中发挥潜在作用。近年来,对唾液酸酶的结构和功能的研究取得了重大进展,唾液酸酶在细菌发病机理中的功能已成为研究的热点。现综述产气荚膜梭菌唾液酸酶分子结构与特性、表达调控、唾液酸酶及其抑制剂的作用,以期为进一步探索产气荚膜梭菌的发病机理与唾液酸酶抑制剂的开发和临床应用提供依据。     

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。     

产气荚膜梭菌肠毒素的致病机理研究进展

产气荚膜梭菌是一种重要的人兽共患病的病原体，可引起人的食物中毒和抗生素相关腹泻，产气荚膜梭菌肠毒素是该菌的一个非常重要的致病毒素，在引起人的胃肠疾病方面起着关键性的作用，本文对产气荚膜梭菌肠毒素产生、细胞毒性和组织学作用以及在胃肠粘膜上造成损伤的致病分子机理等方面的研究内容进行论述。     

产气荚膜梭菌对养牛业的危害及其防制

近年来产气荚膜梭菌对中国养牛业的危害巨大,其流行型别和致病特点较以往也在发生变化,其中C、D型菌对牛致病增多;部分病例呈现慢性型发病症状。作者参考了大量文献对牛产气荚膜梭菌病的流行病学、发病原因、临床症状、病理变化、诊断方法及防制措施进行了综述。     

产气荚膜梭菌肠毒素的分子生物学研究进展

产气荚膜梭菌(Clostridum perfringens)是一类G 产芽胞的厌氧梭菌,可以引起人食物中毒和家畜气肿疽,其致病性很大程度取决于产生不同的外毒素.目前至少已鉴定出20余种不同的产气荚膜梭菌的毒素.根据产气荚膜梭菌的4种主要毒素(α,β,ε,т),可以将产气荚膜梭菌分为A～E5个型.……     

产气荚膜梭菌ε毒素及其疫苗研究进展

产气荚膜梭菌病是由产气荚膜梭菌引起的一种重要的人兽共患传染病,可导致山羊、绵羊等动物的肠毒血症或坏死性肠炎,并且可引起动物脑、心、肺和肾组织的水肿.B型和D 型产气荚膜梭菌所产生的ε毒素是引起动物上述病理变化和死亡的重要因素之一.虽然甲醛灭活的毒素疫苗能对动物产生保护性抗体,但是,灭活苗潜在的安全性原因使其在应用上受到限制.因此,基于ε毒素基因的重组疫苗和弱毒疫苗就成为人们研究的目标.     

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。     

产气荚膜梭菌α毒素的研究进展

产气荚膜梭菌 (Clostridiumperfringens)的致病作用一般由它所产生的胞外酶或毒素诱导。主要有α -毒素、β -毒素、θ -毒素及其他的一些胞外酶。本文针对产气荚膜梭菌α毒素的组成、结构、理化性质、作用机理及分子遗传等方面的研究进展作了简要综述。     

产气荚膜梭菌对家禽业的危害及其预防

近年来,全世界主要养禽国家和地区都普遍存在产气荚膜梭状芽孢杆菌（Clostridium pectingem,Cp）引起的坏死性肠炎（Necrotic enteritis,NE）,尤其是欧美等发达国家,随着抗生素促生长剂的禁用,该病发生越来越严重,不仅使动物生产性能、饲料报酬降低,鸡群死亡率增高,还能通过鸡肉制品引起人的感染,造成巨大的经济损失和人类食品安全问题。     

Clostridium perfringens Type C Enterotoxemia

Forms of enteric disease caused by Clostridium perfringens type C are critically reviewed with emphasis on practical aspects and recent research findings. Available data indicate that more animal species may be fatally infected by type C of this organism than by any other type of C. perfringens. Fatal cases have been recorded in pigs, cattle, sheep, horses and humans. Newborn animals are typically the most susceptible, possibly related to aspects of bacterial colonization, intestinal digestive functions, and to some other, unexplained, factors. Both beta toxin and the bacterial cells are required to initiate pathogenesis at the tips of jejunal villi, and subsequent massive adherence of these cells to necrotic mucosa is a characteristic feature. Although major lesions occur in the intestine, death is due to toxemia. The disease can be effectively controlled by vaccination of the dam. Epizootiology of this disease is a possible area for further studies.     

Clostridium perfringens type C and Clostridium difficile co-infection in foals

Clostridium perfringens type C is one of the most important agents of enteric disease in newborn foals. Clostridium difficile is now recognized as an important cause of enterocolitis in horses of all ages. While infections by C. perfringens type C or C. difficile are frequently seen, we are not aware of any report describing combined infection by these two microorganisms in foals. We present here five cases of foal enterocolitis associated with C. difficile and C. perfringens type C infection. Five foals between one and seven days of age were submitted for necropsy examination to the California Animal Health and Food Safety Laboratory. The five animals had a clinical history of acute hemorrhagic diarrhea followed by death and none had received antimicrobials or been hospitalized. Postmortem examination revealed hemorrhagic and necrotizing entero-typhlo-colitis. Histologically, the mucosa of the small intestine and colon presented diffuse necrosis and hemorrhage and it was often covered by a pseudomembrane. Thrombosis was observed in submucosal and/or mucosal vessels. Immunohistochemistry of intestinal sections of all foals showed that many large bacilli in the sections were C. perfringens. C. perfringens beta toxin was detected by ELISA in intestinal content of all animals and C. difficile toxin A/B was detected in intestinal content of three animals. C. perfringens (identified as type C by PCR) was isolated from the intestinal content of three foals. C. difficile (typed as A(+)/B(+) by PCR) was isolated from the intestinal content in 3 out of the 5 cases. This report suggests a possible synergism of C. perfringens type C and C. difficile in foal enterocolitis. Because none of the foals had received antibiotic therapy, the predisposing factor, if any, for the C. difficile infection remains undetermined; it is possible that the C. perfringens infection acted as a predisposing factor for C. difficile and/or vice versa. This report also stresses the need to perform a complete diagnostic workup in all cases of foal digestive disease.     

国际家禽生产领域应用型研究动态

2011年1月24～25日,一年一度的国际家禽科学研讨会在美国佐治亚州亚特兰大召开,与会者通过病理和环境/管理、营养、生理、加工和产品、禽病5个研究领域的交流讨论,探讨当前国际家禽科学研究的发展趋势和研 究的热点难点问题.会议组织者收到并录用256篇研究论文,其中论文集收录159篇,墙报106篇.     

禽类免疫学研究新进展——记第10次国际禽类免疫学研究组会议

1 会议概况 第10次国际禽类免疫学研究组会议(10th Avian Immunology Research Group Conference,AIRG2008)于2008年6月24～27日在澳大利亚昆士兰州黄金海岸市举行.本次会议由澳大利亚联邦科学与工业组织(CSIRO)、澳大利亚家禽联合研究中心(CRC)、澳大利亚生物安全联合研究中心(CRC)承办.来自中国、美国、英国、澳大利亚、德国、法国、荷兰、意大利、匈牙利、丹麦、加拿大、韩国、印度、越南、以色列等国的150多名代表参加会议.在会议期间,主要以大会报告、墙报和讨论等形式进行了禽类免疫学各个方面研究进展的学术交流,经全体代表讨论确定下次会议将于2010年在匈牙利布达佩斯召开.