Verification of peroral vaccination of pigs against enteropathogenic strains of Escherichia coli

In a large herd of pigs where the parenteral immunisation of pregnant sows by polyvalent vaccine against enteral coliinfections of new-born piglets was performed successfully for several years, an increased occurrence of diseases and mortality of sucking piglets was observed. After screening tests in the herd, six strains of E. coli, differing from the strains contained in the commercial vaccine, were isolated. The obtained strains were employed for preparation of peroral vaccine for sows by means of the modified method after Kohler. In two cycles of sows (48 animals in experimental group and 60 animals in control group), this method was compared with the effectiveness of the commonly used commercial polyvalent parenteral vaccine against enteral E. coli infections of new-born piglets (manufactured by Bioveta, Ivanovice in Haná). In experimental sow groups vaccinated perorally by the new vaccine, the number of live-born piglets increased by 0.475 piglet per litter, the number of reared piglets up to the age of 28 days by 0.904 piglet per litter and the mortality till the age of 28 days decreased by 6.1% as compared with the control vaccinated by commercial vaccine. The results were not statistically significant. The advantages and disadvantages of both vaccination methods are discussed.     

大肠杆菌灭活苗的免疫试验

用甘肃省大肠杆菌的代表血清型和筛选的大肠杆菌菌株原生质体融合菌株及大肠杆菌菌株与沙门氏菌菌株原生质体融合菌株研制的大肠杆菌菌苗进行大肠杆菌灭活苗免疫学试验,试验结果表明菌苗免疫性能好,菌苗的免疫高峰期在30 d左右,凝集抗体滴度在28左右,对动物的保护期在4个月以上,而且稳定性能和安全性能均良好,是一种效果较好的菌苗。     

犊牛腹泻大肠杆菌疫苗的研制与应用

根据南京地区犊牛大肠杆菌腹泻流行病学调查结果,用分离鉴定的犊牛腹泻菌株O78、O26、O15大肠杆菌作菌种,制备油乳灭活疫苗,接种初生犊牛预防犊牛大肠杆菌腹泻。结果表明制备的大肠杆菌油乳灭活疫苗接种初生犊牛能产生良好的免疫保护。     

鸡源大肠埃希氏菌部分生物学特性研究

对从天津地区分离到的71株鸡大肠杆菌的部分生物学特性包括致病性、血清型、耐药特性和免疫原性等进行了研究。结果表明其中60株为致病性菌株,占分离菌株的84.5%;60个致病性菌株共定型出45个菌株,分属O1、O2、O5、O6、O20、O45、O53、O74、O75、O78、O88、O89、O92、O107、O111、O145等16个血清型,其中O78、O88、O2、O45、O53和O145为优势血清型,占定型菌株的73.4%;试验菌株具有广泛的耐药性,60个致病性菌株均为多重耐药。免疫原性测定试验结果表明,O2、O78、O88血清型菌株均可对相同血清型菌株提供很好的保护,但3个血清型菌株之间缺乏有效的保护。     

肉鸡大肠杆菌多价灭活蜂胶苗的研制

从分离鉴定的49株大肠杆菌中筛选出5株致病力强、免疫原性好、具有优势血清型的大肠杆菌作为制苗菌株，经培养灭活后，以蜂胶为佐剂，研制出的肉鸡大肠杆菌多价灭活蜂胶疫苗，使用安全，免疫效果好。用该苗免疫后150d的保护率为100％，无不良反应。该苗4C下保存1年不失效。田间试验结果表明，该苗性能好，免疫后对肉仔鸡、肉种鸡的生产性能无不良影响，鸡群大肠杆菌病的死亡率明显下降。     

The effect of antisera on porcine enteropathogenic Escherichia coli in ligated segments of pig intestine.

Nineteen antisera produced in pigs against 14 enteropathogenic and five nonenterotoxigenic porcine strains of Escherichia coli were tested for their ability to inhibit gut loop fluid accumulation induced by homologous and heterologous organisms. In addition, four antisera produced in pigs by an intensive series of intravenous inoculations and three by a less intensive series of intramuscular injections of a polyvalent E. coli vaccine were evaluated. Antisera were also produced in rabbits against eight strains of porcine enteropathogens and tested in pig gut loops. Fluid inhibiting activity was detected in prevaccinal sera of pigs but not of rabbits. This activity was significantly increased following immunization. When single strains of E. coli were used for immunization the activity of the antisera against heterologous organisms varied considerably from one test strain to another and was usually much less than that against the homologous organism. The activity against heterologous organisms could not be associated with relatedness of the O, K and H antigens of the vaccine and the test strains. Antisera produced against a vaccine made by combining three strains were shown to exert inhibitory effects on heterologous organisms similar to those against homologous organisms. Considerably less activity against homologous and heterologous organisms was present in antisera produced by the series of intramuscular compared with the series of intravenous injections.     

陕西省鸡胚源性大肠杆菌的分离鉴定

从陕西关中六个种鸡场的１９８只死胚及出壳弱雏中分离出９８株大肠杆菌,平均分离率为４９．５％。通过小鸡致病力试验,筛选出６３株具有致病力的菌株,占分离菌的６４．３％。生化鉴定表明,这些致病菌均符合大肠埃希氏菌的生化特性。血清型鉴定可确定６种,其中以Ｏ１、Ｏ２、Ｏ７８为主,分别占鉴定菌的４４．４％（２８／６３）、３３．３％（２１／６３）和９．５％（６／６３）,另三种为Ｏ２２、Ｏ７５、Ｏ８９共占８．０％（５／６３）。有３株未定型,占４．８％（３／６３）。用１６种抗生素进行药敏试验,对先锋霉素Ｖ和恩诺沙星高度敏感,对羧苄青霉素、氨苄青霉素、氯霉素、卡那霉素、磺胺嘧啶、新霉素、链霉素中度敏感。     

豫北地区肉鸡大肠杆菌分离鉴定及其蜂胶灭活苗的研究

从豫北地区部分肉鸡场送检的病料中分离出了24株大肠杆菌，确定2l株菌分属8个血清型，其中02，074，01，078为主要血清型，分别占分离株的28．57％，23．8l％，19．04％，9．52％。药敏试验结果表明，所分离的24株大肠杆菌对丁胺卡那霉素、头孢曲松、头孢噻呋、氟苯尼考最敏感，可作为防治肉鸡大肠杆菌病的首选药物。从中筛选出3株致病力强、免疫原性好、具有优势血清型的大肠杆菌和标准菌株作为制苗菌株。以蜂胶为佐剂，研制出的肉鸡大肠杆菌多价灭活蜂胶疫苗，使用安全，免疫效果好。用该苗免疫后150d的保护率为100％，无不良反应。该苗4℃下保存1年不失效。田间试验结果表明，该苗性能好。免疫后对肉仔鸡、肉种鸡的生产性能无不良影响，鸡群大肠杆菌病的死亡率明显下降。     

Detection of High Pathogenicity Island(HPI) in Pathogenic Escherichia coli of Mink by PCR

[Objective] The paper was to analyze the carrying status of high pathogenicity island(HPI) in pathogenic Escherichia coli of mink.[Method] Eight strains of E. coli were isolated from dead mink, and conducted pathogenicity test of artificial infection. The carrying status of HPI(irp2, fyu A) was detected by PCR. [Result] Eight strains of E. coli were pathogenic E. coli, and the carrying rate of HPI(irp2, fyu A) was 100%,positively correlated with the pathogenicity. [Conclusion] The results lay a foundation for further exploring the pathogenic mechanism of E. coli..     

腹泻水貂检出携带耶尔森菌HPI毒力岛的大肠杆菌

为了解大肠杆菌引起水貂腹泻的机理,进行了小肠结肠炎耶尔森菌HPI毒力岛基因的检测,并对其菌株做毒力试验。用PCR扩增法检测毒力岛基因irp2和fyua,小鼠腹腔注射检测菌株毒力。结果：从3个貂场腹泻病死水貂脏器以及粪便中分离出血清型分别为078、029和038的大肠杆菌,对3个血清型大肠杆菌进行毒力岛检测,均检出携带小肠结肠炎耶尔森菌HPI毒力岛基因irp2和fyua。3个血清型078、029和038的大肠杆菌均使小鼠发病死亡。结果表明水貂腹泻是由携带小肠结肠炎耶尔森茵HPI毒力岛基因irp2和fyua的大肠杆菌引起,该茵对水貂的健康具有潜在的威胁。     

Effects of vaccines on the canine immune system.

The effects of several commercially available polyvalent canine vaccines on the immune system of the dog were examined. The results demonstrated that the polyvalent vaccines used in this study significantly suppressed the absolute lymphocyte count and that most of the polyvalent vaccines significantly suppressed lymphocyte response to mitogen, but had no effect on natural effector cell activity, neutrophil chemiluminescence, nor antibody response to canine distemper virus. The individual vaccine components from the polyvalent vaccines when inoculated alone did not significantly suppress the lymphocyte response to mitogen. However, when canine distemper virus was combined with canine adenovirus type 1 or canine adenovirus type 2, significant suppression in lymphocyte responsiveness to mitogen occurred. The results indicate that interactions between canine distemper virus and canine adenovirus type 1 or canine adenovirus type 2 are responsible for the polyvalent vaccine induced suppression of lymphocyte responsiveness.     

鸡大肠杆菌traT基因的扩增及TraT-DIG探针制备

以致病性Ｅ．ｃｏｌｉ的质粒为模板,用人工合成引物扩增出致病性相关的ｔｒａＴ基因核心部分;将菌株的致病性与ｔｒａＴ基因的扩增结果进行比较,强致病力菌株均扩增出ｔｒａＴ基因,无致病力菌株未扩增出ｔｒａＴ基因,约大多数中等致病力菌株亦扩增出ｔｒａＴ基因。扩增获得的ｔｒａＴ基因经纯化后标记地高辛（Ｄｉｇｏｘｉｎ,ＤＩＧ）研制出ｔｒａＴ－ＤＩＧ基因探针,该探针与鸡沙门氏菌、鸡白沙门氏菌、副伤寒沙门氏菌不发生     

Pathogenicity and immunosuppressive properties of infectious bursal disease "intermediate" strains

This study was conducted to test the pathogenicity and immunosuppressive effects of seven commercially available infectious bursal disease (IBD) vaccines. These vaccine strains are intermediate in their pathogenicity in susceptible specific-pathogen-free (SPF) chickens. One-day-old and 3-week-old SPF chickens were vaccinated with these vaccines. Two weeks after IBD vaccination, they were vaccinated with Newcastle disease virus (NDV). The pathogenic and immunosuppressive effects of the IBD vaccines were evaluated by the antibody response to NDV vaccination, the bursa: body weight index, and histopathological lesions of the bursa. It was found that these strains were highly variable in their virulence and immunosuppressive properties. Three of the strains tested were found to be highly virulent and immunosuppressive; two others were moderate; and two could be classified as mild.     

New serotype 2 and attenuated serotype 1 Marek's disease vaccine viruses: comparative efficacy

Attempts were made, through selection of optimum viral strains, to develop improved vaccines against Marek's disease (MD). Seven attenuated serotype 1 strains and 22 avirulent serotype 2 strains, both alone and in combination with the FC126 strain of serotype 3, were screened for protective efficacy against challenge with virulent and very virulent MD viral strains. The three viruses selected as most promising were evaluated alone and in various combinations and compared with commercially available vaccines, including FC126, bivalent (FC126 + SB-1), and CV1988/C, in 12 separate assays. Two of these new viruses--301B/1 (serotype 2) and Md11/75C/R2 (serotype 1)--were exceptionally protective compared with prototype vaccine strains. Four new monovalent and polyvalent vaccines based on these two isolates protected chickens better than FC126 alone or CV1988/C alone. Three of these new vaccines provided better protection than the bivalent (FC126 + SB-1) vaccine. Protective synergism was noted commonly between viruses of serotypes 2 and 3 but only sporadically between serotypes 1 and 2 or between serotypes 1 and 3. Strain CVI988/C was protective but was no better than FC126 alone, and it was less effective than bivalent (FC126 + SB-1) vaccine, even when used as a bivalent vaccine with FC126 or SB-1.     

Some aspects of the epidemiology and control of Salmonella typhimurium infection in outwintered suckler cows.

Two outbreaks of Salmonella typhimurium infections affected outwintered, spring-calving suckler cows in late pregnancy. The infections spread rapidly both within and between groups of stock on the affected farms, with morbidity in the infected groups varying from 14.5 per cent to over 60 per cent, and mortality in adult cattle varying from 0 to 14.3 per cent. Prophylactic measures included the use of antibiotics and killed vaccines against Escherichia coli, Salmonella dublin, S typhimurium, and Pasteurella multocida. In one outbreak, use was also made of a polyvalent serovaccine and hyperimmune serum against E coli, S typhimurium, and S dublin. In both outbreaks no new cases were reported in the affected groups after the administration of the second dose of vaccine, and there was no resurgence of disease on the affected farms within 18 months of the primary outbreaks.     

60株大肠杆菌的分离与致病性鉴定

大肠杆菌(Escherichia coli,E.coli)是鸡肠道常在菌,部分菌株具有致病性。鸡大肠杆菌病就是由大肠杆菌中的某些致病性菌株引起的鸡感染性疾病。致病性大肠杆菌均携带毒力岛基因ChuA。为鉴定分离自临床病例的鸡大肠杆菌的致病性,本试验采用PCR法检测ChuA基因进行分子生物学鉴定,60株大肠杆菌中有31株属于致病性大肠杆菌,总阳性率为51.67%。     

鸭疫里默氏杆菌多价灭活苗研制的研究报告

用三个血清型的菌株,分别是JYL-1、JYL-2、JYL-7,用两种佐剂,分别是蜂胶和油乳剂共制备了两种多价菌苗,即JYL-1、JYL-2、JYL-7（1、2、7三个血清型）三个RA血清型混合多价蜂胶苗和油乳剂苗。试验结果表明。蜂胶复合佐剂多价苗具有产生免疫保护速度快,免疫持续时间长的优点,接种后第3天即产生部分免疫保护力,第120天时仍具有完全保护力;油乳剂多价苗产生保护力的速度较慢,接种后第10天时开始表现出部分免疫保护,其完全保护力也可持续到接种后第120天。免疫后13d时,免疫保护率可达90％左右。免疫后16d时保护率为100％。免疫后120d时,两种多价菌苗的免疫保护率均可达到100％,免疫后150～180d时,免疫保护率可达800左右。统计学分析证明,菌苗的安全性良好。用3个免疫剂量的菌苗所做的安全试验表明无明显不良反应,菌苗在4℃保存一年,18～22℃室温保存4个月不影响菌苗的免疫效力。田间试验表明,用菌苗免疫鸭群后,可有效地使鸭群抵抗鸭疫里默氏杆菌的感染。     

Avian influenza vaccines and therapies for poultry

Vaccines have been used in avian influenza (AI) control programs to prevent, manage or eradicate AI from poultry and other birds. The best protection is produced from the humoral response against the hemagglutinin (HA) protein. A variety of vaccines have been developed and tested under experimental conditions with a few receiving licensure and field use following demonstration of purity, safety, efficacy and potency. Current licensed vaccines are predominately inactivated whole AI vaccines, typically produced from low pathogenicity (LP) AI virus strains, or occasionally from high pathogenicity AI virus strains. Recently, reverse genetic procedures have been developed that allow construction of vaccine strains using a genetically altered HA gene (changing HP HA proteolytic cleavage site to LP) and a backbone of internal gene segments for safe, high growth production. Other licensed AI vaccines include recombinant fowl poxvirus vector with an AI H5 insert and a recombinant Newcastle disease virus vector with an AI H5 gene insert. The latter vaccine can be mass administered via aerosol application.     

Protection against enteric colibacillosis in pigs suckling orally vaccinated dams: evidence for pili as protective antigens

Pregnant gilts were vaccinated orally with Escherichia coli that produced pilus antigens K99 or 987P. The vaccines were live or dead enterotoxigenic E coli (ETEC) or a liver rough non-ETEC strain which has little ability to colonize pig intestine. Pigs born to the gilts were challenge exposed orally with K99+ or 987P+ ETEC, which did not produce heat-labile enterotoxin or flagella and which produced somatic and capsular antigens different from those of the vaccine strains. Control gilts had low titers of serum and colostral antibodies against pilus antigens, and their suckling pigs frequently had fatal diarrhea after challenge exposure. Serum antibody titers against pilus antigens of the vaccine strains increased in the gilts after vaccination with liver ETEC, and the colostral antibody titers of these gilts were higher than those of controls. Pigs suckling such vaccinated gilts were more resistant than controls to challenge strains were of different pilus types, and it could not be attributed to enterotoxin neutralization by colostrum. In contrast to the live ETEC vaccines given to the pregnant gilts, the liver rough non-ETEC and dead ETEC vaccines stimulated little or no production of antibody against pilu, and the pigs born of these vaccinated gilts remained highly susceptible to challenge exposure. The results support the hypothesis that pilu can be protective antigens in oral ETEC vaccines. It was indicated that in the system reported, protection depended on living bacteria for the production of pilus antigens in vivo or for the transport of pilus antigens across intestinal epithelium.     

A new polyvalent vaccine against enteral infections in newborn calves

The most frequent microbial causative agents of massive diarrheas in new-born calves kept on large cattle farms in the CSSR are rotaviruses, coronaviruses and enterotoxigenic strains of E. coli, manifesting themselves as complicated virus-bacterial infections. An inactivated polyvalent adjuvant vaccine has been developed for the prevention and specific prophylaxis of these enteral infections; the vaccine contains bovine rotavirus, bovine coronavirus and three enterotoxigenic serotypes of E. coli with protective antigen K 99. The rotavirus and coronavirus are propagated on the stable cellular line MDBK and inactivated with 0.2% formalin, the Escherichia strains are submersed in the MINCA culture medium during their cultivation and inactivated with 0.5% formalin. The vaccine was prepared as a blend of the same amounts of rotavirus and coronavirus and of such an amount of bacterin so that 1 ml of the vaccine will contain 10(9) bacteria. One part of oil adjuvant was added to five parts of the virus-bacterial blend and the blend was homogenized in the Ultraturax apparatus. The vaccine is to be used for immunization of pregnant cows and heifers; in these animals it induces the production of specific antibodies to all antigens contained in the vaccine. Its immunogenic effects were checked in 32 calves and 38 cows in the herds with the occurrence of diarrheas caused by both enteropathogenic viruses and enterotoxigenic escherichia. It was demonstrated that the inactivation did not influence in either of the viruses the process of inducing the production of specific antibodies, and the antibody response of the calves and heifers after application of 2 ml of complete inactivated vaccine was equally strong as after application of live vaccine containing only rotavirus and coronavirus. The level of the rotavirus antibodies increased on the average 30 times and 200 times, coronavirus antibodies twice and four times. The antibody response to coronavirus was negatively influenced by the relatively high levels of antibodies before vaccination. The antibody response to antigen K 99 was expressive in all cases.