产气荚膜梭状芽孢杆菌气悬状态下存在形式的研究

产气荚膜梭状芽孢杆菌是动物舍空气粪便污染的指示菌种,他们的含量反映了动物舍卫生状况以及动物体相应疾病的可能感染。通过对 Ｋ Ｓ９２ 喷冲器空气样品加热 ８０℃,２０ 分钟处理,结果证明该菌群几乎 １００％ 以芽孢形式气悬存在。     

The impact of various browse feeds with different tannin content on the fecal shedding of Clostridium perfringens in West African dwarf sheep

In 1994 and 1995 leaves from eight browse feeds, containing tannins in different amounts (BF), were fed to West African Dwarf Sheep in Benin to evaluate their impact on Clostridium perfringens in the intestinal tract. An inhibitory impact of various BF on the growth of C. perfringens was assessed in in-vitro assays before, and thus a potential use of these leaves as a preventive diet against C. perfringens enterotoxemia in small ruminants was assumed. Surprisingly, an inhibitory impact of the BF on the shedding of C. perfringens in the feces of West African Dwarf Sheep could not be shown in seven of the eight BF examined. However, the pattern of inhibition of unlike C. perfringens toxovars may differ and a selective inhibitory impact of the BF Dialium guineense on C. perfringens toxovar D may be assumed.     

Studies of necrotizing enteritis of suckling piglets (Cl. perfringens typc C enterotoxemia) in industrialized sow breeding units. 3. Experimental reproduction of the disease]

Experimental reproduction of necrotising enteritis of sucking pigs was successfully achieved by using both Clostridium perfringens Type C strains, which had been isolated from sucking pigs with necrotising enteritis, and Type C strain 3628 of A.T.C.C. (sub-type C1). The lethal dose for sucking pigs was between 20 X 10(6) and 12 X 10(7) pathogens per animal. The disease could not even be induced by repeated application of no-bacterial toxin of Cl. perfringens Type C nor by administration of Cl. perfringens Type A strains which had been cultured from broilers with necrotising enteritis. Necrotising enteritis was found to develop in two phases in sucking pigs. First, the pathogen will deposit to the villous epithelium and then penetrate the superficial strata of the mocous membrane. In the second phase, the villous structure will be destroyed by the lethal, haemolysing, and necrotising toxins of Cl. perfringens. The role played by individual toxin fractions is discussed together with the importance of humoral and localised infection defence. Sucking pigs may be sufficiently protected against infection based on single or ten-fold lethal infectious dosage by two vaccinations of the mother animal, five and three weeks prior to parturition, using "Enterotoxaemia Vaccine Dessau bivalent". Infection then would not occur unless a hundredfold lethal dose was applied. Characteristics include diarrhoea, apathy, exhaustion, and death.     

Incidence of Clostridium perfringens in broiler chickens and their environment during production and processing.

During a calendar year, a study was conducted involving 16 broiler flocks on four different farms, two farms belonging to each of two major U.S. poultry integrators. As determined by the detection of Clostridium perfringens in fecal or cecal samples, 15 (94%) of the flocks became positive for this bacterial enteropathogen, and only one remained negative throughout the 6-to-8-wk rearing period. Paper pads beneath chicks that were transported from the hatchery to the rearing house were contaminated with C. perfringens in 15 (94%) of the flocks. When sampled biweekly through grow out, 13 of the flocks were C. perfringens positive at 2 wk of age. These results suggest that colonization of the intestinal tract of broilers by C. perfringens is an early event. Of the environmental samples, all but feed in the hopper were contaminated before placement for at least one of the rearing periods. All sample types were contaminated at some point during the 6-to-8-wk grow-out period. Of the on-farm environmental samples, the highest incidences (percentage positive) of C. perfringens were detected in wall swabs (53%), fan swabs (46%), fly strips (43%), dirt outside the house entrance (43%), and swabs of workers' boots (29%). Birds were usually transported to the processing plant in coops that were already contaminated with C. perfringens. In the plant, C. perfringens was isolated more frequently from samples of scald water than from those of chill water. Clostridium perfringens was recovered from broiler carcasses after chilling in 13 (81%) of the 16 flocks. The proportion of C. perfringens-positive carcasses for the contaminated flocks ranged from 8% to 68% with a mean of 30%.     

Proteases of Clostridium botulinum. V. Studies on the serological relationship between proteases from Clostridium botulinum and other spore-forming bacteria

By the use of the electrophoretic casein precipitating inhibition test (CPI-test) the serological relationship between proteolytic enzymes produced by different species within the genera Clostridium and Bacillus has been tested. The proteases produced by Clostridium botulinum types A, B, C, D and F cross-reacted with each other. Clostridium botulinum strain 84 was inhibited by antiproteases produced against Clostridium sporogenes, Clostridium botulinum types C and F (protease F I and F II), but not by antiproteases against Clostridium botulinum types B and F (protease II), Clostridium bifermentans and Clostridium perfringens. The protease of the newly described Clostridium botulinum strain 89 (type G) was inhibited by Clostridium sporogenes antiprotease, but not by any of the other antiproteases. It is not possible to differentiate between Clostridium botulinum, Clostridium sporogenes and Clostridium perfringens by use of serological differentiation of their proteolytic enzymes. The protease of Clostridium bifermentans is not serologically related to any of the species tested in this investigation. Proteases produced by different Bacilli were not inhibited by antiproteases from Clostridium botulinum types B, C and F, Clostridium sporogenes, Clostridium bifermentans, and the two strains of Clostridium perfringens tested. This investigation indicates a serological relationship between proteases from different Clostridium species, but not a serological relationship between proteases produced by the Clostridium species and Bacillus species tested.     

Studies of necrotizing enteritis of suckling piglets (Clostridium perfringens type C enterotoxemia) in industrialized sow breeding units. 4. Epizootiology]

Necrotising enteritis had been the cause of death of 4.9 per cent in 5,177 nursed piglets, which was established by pathological examination. The number of piglets, in that context, which had come from industrialised sow breeding units was equivalent to 92 per cent. The nursed piglet held the third position, next to smaller ruminants (19.4 per cent) and fowl (6.0 per cent), with regard to the occurrence of Clostridium perfringens enterotoxemia or necrotising enteritis in 112,218 animals which were pathologically examined after death. Necrotising enteritis so far has been rare in the GDR. No regional accumulation has been observed. Several outbreaks on industrialised sow breeding units actually remained stationary. The occurrence of the disease may be favoured by a number of factors which are conducive to accumulation of Clostridium perfringens Type C in a given stock. Group keeping of pregnant sows, simultaneous farrowing of larger groups of sows, group treatment of nursed piglets, using neomycin, chloramphenicol, oxytetracycline, and other antibiotics to which Clostridium perfringens is primarily resistant or has acquired resistance in the course of time are some of those contributive factors. Transmission of Clostridium perfringens Type C through feedstuff is possible, though it would lead to a real outbreak only by high intensity of the contamination, and it played a minor role in proliferation of the disease. 3479 Clostridium perfringens strains were isolated from 9,481 animals, both clinically intact and after death, with 30 species being included. Type classification revealed 2454 strains of Type A (70 per cent), 204 of Type D (5.88 per cent), 164 of Type C (four per cent), and 48 of Type B (1.34 per cent). There were 688 atoxic strains (17 per cent). Swine is the major carrier of Clostridium perfringens Type C, with 87 per cent of all Clostridium perfringens Type C strains having been isolated from swine. Swine was followed by fowl (four per cent), sheep (four per cent), cattle, rabbit, and dog (1.27 per cent each). Clostridium perfringens Type C was obtained from the faeces of clinically intact sows in seven instances, including two cases with sows (0.46 per cent) from farms with no previous record of necrotising enteritis.     

Evaluation of enzyme-linked immunosorbent assay for diagnosis of Clostridium perfringens enterotoxemias.

Two double sandwich enzyme-linked immunosorbent assays (ELISA) for Clostridium perfringens beta and epsilon toxins were assessed for routine diagnosis of enterotoxemias on intestinal contents of 151 sheep that died suddenly. Conventional tests (mouse assay and culture of organism) showed that 21 specimens were positive for Clostridium perfringens type C (beta toxin) and 39 were positive for Clostridium perfringens type D (epsilon toxin) enterotoxemias. Comparison of the ELISA results with conventional assays gave sensitivity and specificity rates respectively of 90.5% and 89.2% for beta toxin assay and 97.4% and 94.6% for epsilon toxin assay. With further refinement to improve the performance of the assay for beta toxin these tests could serve as a substitute for conventional tests in the laboratory diagnosis of Clostridium perfringens types B, C and D enterotoxemias.     

A型产气荚膜梭菌灭活疫苗类毒素含量与疫苗攻毒保护率之间的平行关系研究

测定了制苗菌液中外毒素对小白鼠的最小致死量,并将该制苗菌液按《兽用生物制品规程》（以下简称《规程》）[1]方法制成A型产气荚膜梭菌灭活疫苗,按《规程》方法进行安全和效力检验。结果表明：6批疫苗安全检验全部合格;疫苗保护率与疫苗中类毒素含量呈正相关。     

The occurrence of enterotoxigenic Clostridium perfringens strains in the feces of dogs and cats

A total of 147 faecal specimen of dogs and cats was examined with cultural method for the occurrence of Cl. perfringens and its enterotoxin by using a reversed passive latex agglutination test (Pet-RPLA). Cl. perfringens could be detected in 77.9% of the samples of dogs (n = 68) and 65.6% of cats (n = 32) with diarrhoea in germ counts of 10(4)-10(10) cfu/g faeces. In the group of non diarrhoeic dogs (n = 39) and cats (n = 8) Cl. perfringens was found in 53.9% and 50% of the samples, the germ counts revealed 10(4)-10(8) cfu/g faeces. The enterotoxin of Cl. perfringens was detected in 48.5% of the samples of dogs and 28.1% of cats with diarrhoea. On the other hand this toxin could not be detected in any faecal specimen of non diarrhoeic animals. The in vitro detection of Cl. perfringens enterotoxin was successful at 65% of 20 strains, that had been isolated from faecal samples with enterotoxin. Also 2 Cl. perfringens strains isolated from faeces of non diarrhoeic dogs proved to be enterotoxigenic. The present test results given reason to believe that enterotoxigenic Cl. perfringens strains are involved in the complex of enteric disease of dogs and cats.     

不同方法对牛舍气载魏氏梭菌型别的研究

分别采用ELISA、多重PCR方法对从一个犊牛舍分离到的魏氏梭菌进行型别研究,结果显示:ELISA检测结果为88%的菌种属于A型,3.4%为C型,8.6%是D型;而多重PCR结果均为A型。     

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.     

植物精油与丁酸钠的体外协同抑菌效果研究

本试验旨在研究植物精油与丁酸钠的体外协同抑菌效果。采用牛津杯法,测定肉桂醛、百里香酚和香兰素对于4种细菌(大肠杆菌、沙门氏菌、产气荚膜梭菌、乳酸菌)的抑菌效果。并将单方和复合植物精油分别与丁酸钠复配,测定其抑菌效果。结果表明:3种植物精油均对大肠杆菌、沙门氏菌、产气荚膜梭菌有明显抑制作用,但对乳酸菌无抑制作用,在相同浓度下,抑菌效果为肉桂醛香兰素百里香酚。肉桂醛与香兰素复合植物精油抑菌效果优于单方植物精油,当肉桂醛与香兰素的质量比为6∶1时抑菌效果最佳。丁酸钠没有显示出抑菌作用,但丁酸钠与植物精油复合可明显降低植物精油的使用量。综上所述,不同植物精油的复合具有协同作用,植物精油和丁酸钠之间也存在着协同作用。     

几种中草药提取物对感染产气梭菌肉鸡生长性、血液生化指标及肠道组织学的影响

本试验将560只Ross 308肉鸡随机分为7组,每组8个重复,每个重复10只鸡。各组日粮处理如下:对照组饲喂基础日粮,未感染产气梭菌,T1组感染产气梭菌,T2组感染产气梭菌+0.2 g/kg阿维霉素,T3组感染产气梭菌+0.40 g/kg百里香酚,T4组感染产气梭菌+0.2 g/kg血根碱,T5组感染产气梭菌+0.5 g/kg香芹酚、肉桂醛和辣椒素混合物,T6组感染产气梭菌+0.2 g/kg百里香酚和茴香混合物。结果显示:T2组第3周料重比显著高于对照组(P<0.05)。T1组屠宰率显著下降(P<0.05),小肠重量显著增加(P<0.05)。第4周时,T6组血液总蛋白和球蛋白含量显著升高(P<0.05),T5组肝脏谷丙转氨酶活力显著升高(P<0.05)。T5和T6组硫代巴比妥酸反应物含量均显著升高(P<0.05)。同样,T5和T6组绒毛高度和隐窝深度也显著增加(P<0.05)。综上所述,与抗生素相比,肉鸡日粮添加中草药制剂在维持产气荚膜梭菌感染肉鸡生长性能和血液生化特性方面具有应用的优势。     

Enterotoxemia in two foals.

Two Quarter Horse foals from different premises died from enterotoxemia. Clostridium perfringens toxins alpha and beta were demonstrated in the foal's intestines by mouse protection tests. Clostridium perfringens type C was isolated from the intestines of each foal. Histologic examination revealed hemorrhage, necrosis, and massive numbers of C perfringens.     

The possibility of the serological differentiation of Clostridium species using enzyme immunoassays

A method for serotyping and diagnosis of 30 selected Clostridia strains of 12 different species by an enzyme-immuno-assay using polystyrene balls as a solid phase is described and tested for its efficiency. The reference strains and the homologous test strains could be differentiated from the heterologous in principle. A reliable detection of the several serotypes of Cl. perfringens was not perfectly to achieve with the conjugates used here, cross-reaction with Cl. chauvoei could be removed by absorption. The conjugate of Cl. bifermentans reacted with Cl. sordellii and Cl. difficile too, and must be absorbed prior any diagnostic applications with vegetative cells of the corresponding strains. Concerning the antigenic relationships between the Clostridia strains used here, the results of Ellner and Green (7, 8) as well as of Poxton and Byrne (14) could be reconfirmed. Moreover the applied technique offers the possibility to come to a more detailed result concerning the degree of antigenic relationship. The developed method is a valuable tool for the differentiation of pathogenic Clostridia and within the group Cl. bifermentans/Cl. sordellii/Cl. difficile a rapid diagnosis at the species level could be achieved. Some limitations by cross-reactions are given, but results can be improved by absorption of the conjugates.     

Dietary effects on bifidobacteria and Clostridium perfringens in the canine intestinal tract

Dietary effects on the intestinal microflora have gained increasing interest because of the evidence that a balanced micro ecology in the gut is important for health and well being. The aim of the present study was to evaluate the effect of different diets on faecal counts of bifidobacteria and Clostridium perfringens in dogs. Two extruded, dry diets, one supplemented with 3% chicory (1.5% inulin), a non-digestible oligosaccharide (NDO) and the other with 3% glucose (GLU) were compared with a protein rich diet (PR+) based on low quality animal derived protein sources (NDO 265, GLU 259, PR+ 726 g crude protein/kg dry matter; greaves meal and bovine lung as protein sources in PR+). Nine adult beagles were subjected to a consecutive cross-over trial. All dogs started with diet PR+, after which groups of four dogs (group A) received GLU and the other five dogs (group B) received NDO. After an intermediate wash-out period with diet PR+ for 3 weeks the A dogs were switched to diet NDO and B dogs to GLU. In the final period all dogs were fed with diet PR+. Faecal samples were collected during each period for dry matter and pH measurements. Faecal bifidobacteria and Cl. perfringens were quantified in fresh samples at the end of each feeding period and additionally on the first days after feed change from the dry diets to diet PR+. Diets NDO and GLU increased faecal dry matter and reduced faecal pH from 6.9 to 7.4 with the high protein diet to 5.9-6.5. The dry diets induced a firmer faecal consistency and a lower faecal pH, with no significant difference between NDO or GLU. Clostridium perfringens was found in all faecal specimens after feeding PR+ with counts of log 8.2-8.8 colony forming units (cfu)/g faeces. Both dry diets reduced the counts of Cl. perfringens significantly (log 3.3-4.0 cfu/g faeces). Switching from the dry diets to the high protein diet induced an increase of Cl. perfringens within 1 day, independent of the previous diet. In dogs fed PR+, bifidobacteria were detected in only four faecal samples and exclusively in the initial feeding period. During the remainder of the experiment the counts fell below the detection limit (log 6 cfu/g faeces). The faecal concentrations of bifidobacteria increased with both dry diets. Slightly higher concentrations (log 9.6-9.7 cfu/g faeces) were obtained from dogs fed the dry diet containing NDO compared with the diet containing glucose (log 9.3-9.4 cfu/g faeces). The increase was small which may be related to the level of total fermentable carbohydrates in both diets which alone increase remarkably the total counts of bifidobacteria. In conclusion, distinct dietary effects on the faecal counts of Cl. perfringens and bifidobacteria with a clear antagonistic pattern were observed. The main factor was the protein source and level in the diet. In this case, NDO favoured the concentrations of bifidobacteria to a limited degree. Further studies are needed to evaluate time effects, metabolic consequences and the potential implication for health promotion in pets.     

Clostridial myonecrosis in horses (37 cases 1985-2000)

REASONS FOR PERFORMING STUDY: Previous reports of clostridial myonecrosis have either focused on individual case reports or have been small retrospective studies reporting very high mortality rates. OBJECTIVES: The objective of this study was to describe the outcome of cases of clostridial myonecrosis submitted to 2 referral equine hospitals in the United States over a 15 year period. METHODS: A retrospective study of case material selected on the basis of positive Clostridium spp. culture or the identification of Clostridium spp. by specific fluorescent antibody testing from soft tissue wounds was performed at Cornell and Wisconsin. RESULTS: 37 cases of clostridial myonecrosis were documented. Twenty-seven horses survived, 8 were subjected to euthanasia and 2 died during treatment for an overall survival rate of 73%. Twenty-five cases (68%) were associated with Clostridium perfringens alone, 6 cases (16%) with Cl. septicum alone, 4 cases with mixed clostridial infections (11%), 1 case with Cl. sporogenes and 1 with an unspeciated Clostridium spp. The highest survival rate of 81% was documented for those cases from which Cl. perfringens alone was isolated. The most common antecedent condition prior to referral was colic. The myonecrotic lesion occurred within 6-72 h of a soft tissue injection in 34 cases but was associated with a wound or laceration in the remaining 3 cases. Of the 34 cases associated with recent injections, 24 were associated with i.m. injections in the cervical region, 4 in the semimembranosus/semitendinosus region, 3 in the gluteal region, 2 with perivascular leakage of drugs administered into the jugular vein and 1 case developed simultaneously in the gluteal and neck region following injections at both sites. CONCLUSIONS: Clostridial myonecrosis can occur following the i.m. or inadvertent perivascular administration of a wide variety of commonly administered drugs. It is most common in the neck musculature. Aggressive treatment can be associated with survival rates of up to 81% for cases due to Cl. perfringens alone. Survival rates for other Clostridial spp. tend to be lower. POTENTIAL RELEVANCE: A combination of high dose i.v. antibiotic therapy and surgical fenestration/debridement is the best approach to cases of clostridial myonecrosis. With rapid diagnosis and therapeutic intervention, horses may have up to an 81% chance of survival.     

产气荚膜梭菌毒素基因分型PCR检测方法的建立及初步应用

建立一种快速鉴别诊断不同型产气荚膜梭菌的PCR检测方法,为动物产气荚膜梭菌病的快速诊断及流行病学调查提供有效的技术手段。克服传统鉴定方法耗时长、费用高的缺点,提高了检测效率。通过对产气荚膜梭菌α毒素、β毒素、ε毒素和ι毒素基因序列分析,利用Premier5.0软件设计并合成了5对特异性引物,建立了针对5种不同型产气荚膜梭菌的PCR鉴别诊断方法。通过反复试验确定了最佳退火温度为53℃。通过灵敏度试验表明,PCR检测方法最低能检测到的DNA浓度α毒素为308pg/μL,β毒素、ε毒素为30.8pg/μL,ι毒素A为0.122pg/μL,ι毒素B为0.05pg/μL。通过特异性试验表明,本方法具有较高的特异性。同时,通过对本方法检测出的阳性样品16S rRNA序列分析发现,与GenBank中的其他产气荚膜梭菌的16S rRNA序列同源性均在98%以上。表明建立的检测方法灵敏度高、特异性强,可以应用于动物产气荚膜梭菌病的实验室诊断。     

西藏那曲牦牛源产气荚膜梭菌的分离鉴定及生物学特性

利用细菌培养、生化鉴定、小鼠致病性试验、PCR技术等方法对西藏那曲市多起牦牛猝死病例进行诊断和分析.结果表明,从病死牦牛脏器中分离得到3株产气荚膜梭菌,命名为AD-01、AD-02和BG-01.其中AD-01和AD-02分离株属于A型,BG-01分离株属于C型.通过对分离株16S rRNA进行序列比对并制作进化树分析发...     

Clostridial enteric infections in pigs.

Clostridium perfringens types A and C and Clostridium difficile are the principal enteric clostridial pathogens of swine. History, clinical signs of disease, and gross and microscopic findings form the basis for a presumptive diagnosis of C. perfringens type-C enteritis. Confirmation is based on isolation of large numbers of type-C C. perfringens and/or detection of beta toxin in intestinal contents. Diagnosis of C. perfringens type-A infection, however, remains controversial, mostly because the condition has not been well defined and because type-A organisms and their most important major (alpha) toxin can be found in intestinal contents of healthy and diseased pigs. Isolation of large numbers of C. perfringens type A from intestinal contents, in the absence of other enteric pathogens, is the most reliable criterion on which to base a diagnosis. Recently, beta2 (CPB2) toxin-producing C. perfringens type A has been linked to disease in piglets and other animals. However, implication of CPB2 in pathogenesis of porcine infections is based principally on isolation of C. perfringens carrying cpb2, the gene encoding CPB2, and the specific role of CPB2 in enteric disease of pigs remains to be fully defined. Clostridium difficile can also be a normal inhabitant of the intestine of healthy pigs, and diagnosis of enteric infection with this microorganism is based on detection of its toxins in feces or intestinal contents.