嗜酸乳杆菌和两歧双歧杆菌体外粘附Caco-2细胞及其对病原菌粘附性能的影响

以Caco-2细胞作为体外模式,观察嗜酸乳杆菌、两歧双歧杆菌、大肠杆菌K88和猪霍乱沙门氏菌对Caco-2细胞的粘附特性,并探讨嗜酸乳杆菌和两歧双歧杆菌的抗粘附作用。结果表明,所试4种细菌菌株均表现出很强的粘附Caco-2细胞的特性;粘附抑制试验表明,无论在排斥试验、竞争试验还是置换试验,嗜酸乳杆菌或两歧双歧杆菌均能明显抑制大肠杆菌K88和猪霍乱沙门氏菌的粘附;杀菌试验表明,嗜酸乳杆菌或两歧双歧杆菌上清液均能显著抑制病原菌的生长,但上清液用胰蛋白酶、蛋白酶K、乳酸脱氢酶处理后,杀菌作用明显降低,表明杀菌作用是乳酸和蛋白质样物质共同作用的结果。     

嗜酸乳杆菌细胞壁提取物对致病性大肠杆菌粘附鸡肠纹状缘膜的影响

为研究嗜酸乳杆菌细胞壁提取物对致病性大肠杆菌(E.coli)粘附鸡肠纹状缘膜的影响,本实验以雏鸡小肠纹状缘膜为模型,以嗜酸乳杆菌和鸡致病性E.coli O78为研究对象,提取嗜酸乳杆菌表层蛋白、肽聚糖及E.coli O78菌毛,雏鸡小肠纹状缘膜,采用固相粘附试验和生物素标记法从分子间相互作用的关系评价了嗜酸乳杆菌细胞壁提取物对菌毛粘附的抑制作用,结果表明:表层蛋白和肽聚糖对菌毛粘附具有明显的抑制作用,呈浓度依赖性抑制菌毛与纹状缘膜的结合,具有竞争性拮抗作用,这主要是由空间占位造成的。肽聚糖的抑制作用相对较小。     

鸡源益生嗜酸乳杆菌的分离及生物特性初报

从10日龄健康小鸡的小肠中成功分离筛选出有抑菌作用的嗜酸乳杆菌M16。颉颃病原菌试验表明,该菌株的代谢产物在体外具有抑制杀灭鸡大肠埃希氏菌O78、鸡白痢沙门氏菌O79和金黄色葡萄球菌C58000的作用,是微生态制剂可选用的优良菌株。     

漫谈链霉素的毒性反应

链霉素是家禽临诊应用较为广泛的一种抗菌药物,它对大多数革兰氏阴性细菌,如对沙门氏菌、结核杆菌、大肠杆菌、鸡白痢杆菌、鸡伤寒杆菌、嗜血杆菌、亚利桑那菌、巴氏杆菌等病原菌都有抑杀作用.因此,可用链霉素来防治禽霍乱、鸡伤寒、副伤寒、传染性鼻炎、溃疡性肠炎、霉形体病及鸡白痢杆菌病等禽病.此外,链霉素对钩端螺旋体病也有效.     

20种中草药制剂抑菌试验初报

选择２０种不同的中草药制剂（煎剂，单方针剂、复方针剂）分别对禽巴氏杆菌、鸡白痢沙门氏菌、鼠伤寒沙门氏菌，猪丹麦杆菌，猪大肠杆菌，采用纸片和抑菌法进行抑菌试验，表明，２０种制剂对５种病原菌的抑制效果强弱不同，穿心莲针剂、草珊瑚针剂、板蓝根苦参复合液，板蓝根草珊瑚复合液对５病原菌均有不同程度的抑制作用，试验还表明，制剂的配方，工艺不同，其抑制细菌效果亦有差异，复方针剂抑菌效果比单方针剂有所增强，具有协     

解决沙门氏菌困扰养禽业的技术途径

沙门氏菌(Salmonella)是一类肠道杆菌,沙门氏菌属有2400多个血清型菌株.与家禽有关的沙门氏菌分类:一类是以宿主特异性(Host-specifie)且不能运动的成员--鸡白痢沙门氏菌(S.Pullorum)和禽伤寒沙门氏菌(S.gallinarium),它们分别为鸡白痢和禽伤寒的病原,多数情况下仅感染家禽和某些鸟类.另一类是宿主非特异性(Host-nonspeci6c)沙门氏菌,主要有鼠伤寒沙门氏菌(S.typhimudum)、肠炎沙门氏菌(S.enteritidis)、海德堡沙门氏菌(S.heideberg)、海德沙门氏菌(S.hadar)等.它们存在于环境中,能感染非常广泛的动物,是禽副伤寒的病原.     

鸡沙门氏菌病的防治

<正>鸡沙门氏菌病是由沙门氏菌属引起的一组传染病,主要包括鸡白痢、鸡伤寒和鸡副伤寒。沙门氏菌属是一大属血清学相关的革兰氏附性杆菌,共有3000多个血清型。禽沙门氏菌病依据其病原体不同可分为五种类型。由鸡白痢沙门氏菌所引起的称为鸡白痢,由鸡伤寒沙门氏菌引起的称为禽伤寒,而其他有鞭毛能运动的沙门氏菌所引起的禽类疾病则统称为禽副伤寒。诱发禽副伤寒的沙门氏菌能广泛地感染各种动物和人类。因此,     

禽沙门氏菌病的诊治

正禽沙门氏菌病是由肠杆菌科沙门氏菌属中的一种或多种沙门氏菌引起的禽类疾病的总称。沙门氏菌有2000多个血清型,广泛存在于人和多种动物的肠道内。在自然界中,家禽是最主要的贮存宿主。该菌根据细菌抗原结构的不同可分为三类:鸡白痢、禽伤寒和禽副伤寒。鸡白痢和禽伤寒沙门氏菌有宿主特异性,主要引起鸡和火鸡发病,而禽副伤寒沙门氏菌则能广泛感染多种动物和人。1鸡白痢本病是由鸡白痢沙门氏菌引起的禽类传染病,主要     

江苏扬州某蛋种鸡场沙门氏菌耐药性调查与分析

<正>沙门氏菌为肠杆菌科沙门氏菌属成员,引起的鸡白痢、禽伤寒及禽副伤寒等是鸡常见的细菌性传染病,可导致鸡生产性能和繁殖能力下降,甚至急性死亡,给养禽业造成严重的经济损失。在引起禽副伤寒的众多沙门氏菌中,鼠伤寒沙门氏菌、肠炎沙门氏菌、海德堡沙门氏菌等是导致人类食物中毒的最为常见病原菌,具有重要的公共卫生意义。     

农村禽散养户禽沙门氏菌病的防治

禽沙门氏菌病是由禽沙门氏菌属中的一种或多种沙门氏菌所引起的急性或慢性疾病总称，依病原体不同可分3种，由鸡白痢沙门氏杆菌引起的鸡白痢，由鸡伤寒沙门氏杆菌引起的禽伤寒和以鼠伤寒沙门氏杆菌为主的多种沙门氏杆菌引起的禽副伤寒。其中鸡白痢为最常见，危害也最大，笔者曾深入农村，走访调查了许多养殖户，发现养殖环境卫生较差，此病发病率，死亡率都较高。     

乳酸菌和大肠杆菌对固定化犬肠道黏蛋白模型的黏附性

采用固定黏蛋白模型,结合细菌同位素γ-32P-ATP标记法,探讨犬源肠球菌E01和E16、犬源大肠杆菌DE、鸡源德氏乳酸杆菌德氏亚种N11及猪源约氏乳杆菌JJB3和致病性大肠杆菌ATCC25922和CVCC2060对本地犬各肠段黏蛋白的黏附能力;肠球菌E16和大肠杆菌DE各自的黏附机制;2株犬源肠球菌以3种作用方式（排斥、竞争、取代）对2株致病性大肠杆菌的黏附抑制作用。结果表明,各测试菌株在犬各肠段黏蛋白模型上的黏附值均不同;2株犬源肠球菌和1株猪源乳酸菌的黏附性能显著优于犬源大肠杆菌DE和2株致病性大肠杆菌;乳酸肠球菌E16表面的碳水化合物结构和糖蛋白参与了黏附过程,大肠杆菌菌体蛋白在黏附过程中发挥一定作用;乳酸肠球菌的黏附受体对高碘酸钠和胰蛋白酶处理不敏感,大肠杆菌DE的黏附受体具有碳水化合物结构,可能为糖蛋白类物质;在肠球菌与病源菌的3种作用方式中,取代和排斥方式对病原菌黏附抑制效果较好。这表明2株犬源肠球菌具开发为益生菌的潜力。     

Population of Salmonella serovar typhimurium in the cecum of gnotobiotic chickens with Escherichia coli and intestinal bacteria.

To test the interaction between various species of bacteria and Salmonella serovar typhimurium (S. typhimurium), the population of S. typhimurium was measured in the cecum of gnotobiotic chickens in the presence of Escherichia coli (E. coli) and one of the four intestinal bacteria; Lactobacillus acidophilus. Clostridium perfringens, Bifidobacterium thermophilum and Bacteroides vulgatus. Competitive exclusion of S. typhimurium by di-flora chicken was not demonstrated. But the population of S. typhimurium was temporarily suppressed in di-flora chickens with E. coli and L. acidophilus. In penta-flora chickens with E. coli and these four intestinal bacteria, the population of S. typhimurium was suppressed for only 2 days. In normalized chickens, the population of S. typhimurium was markedly suppressed.     

In vitro adhesion of an avian pathogenic Escherichia coli O78 strain to surfaces of the chicken intestinal tract and to ileal mucus

The role of fimbria in adherence of an avian pathogenic Escherichia coli (APEC) O78 strain 789 to chicken intestine was studied. Bacterial adhesion to tissue sections representing the regions within the chicken intestinal tract was determined by using immunohistochemical methods. E. coli 789 grown to express the type 1 fimbria adhered efficiently to the crop epithelium, to the lamina propria of intestinal villi, and to the apical surfaces of both the mature as well as the crypt-located enterocytes in intestinal villi, whereas no adhesion to mucus-producing goblet cells was detected. The adhesion was inhibited by mannoside and the role of type 1 fimbriae in the observed adhesion was confirmed with a recombinant strain expressing type 1 fimbriae genes cloned from E. coli and Salmonella enterica. E. coli 789 strain grown to favor AC/I fimbriae expression as well as the recombinant E. coli strain expressing the fac genes adhered to goblet cells but only poorly to the other epithelial sites. E. coli strain 789 as well as S. enterica serovar Typhimurium IR715 and S. enterica serovar Enteriditis TN2 strains were able to multiply in ileal mucus medium. The type 1 fimbria expressing bacteria adhered to the ileal mucus, whereas the AC/I fimbriated strains showed poor adherence to the mucus. The adhesion of E. coli 789 onto the crop epithelium and the follicle associated epithelium of the chicken ileum was efficiently inhibited by an adhesive strain ST1 of Lactobacillus crispatus isolated from chicken, whereas poor inhibition of E. coli adherence was observed with the weakly adhesive L. crispatus strain 134mi. The type 1 fimbriae may be important in colonization of the chicken intestine by APEC and Salmonella.     

Construction and evaluation of a delta cya delta crp Salmonella typhimurium strain expressing avian pathogenic Escherichia coli O78 LPS as a vaccine to prevent airsacculitis in chickens.

Avian pathogenic strains of Escherichia coli cause a number of extraintestinal diseases in poultry, including airsacculitis and colisepticemia. Expression of O78 lipopolysaccharide (LPS) is frequently associated with pathogenic isolates. Salmonella, a common poultry contaminant, is a major public health concern. The purpose of this work was to develop an E. coli vaccine for poultry with the use of an attenuated Salmonella typhimurium carrier that would benefit both the bird and the consumer. Orally administered attenuated S. typhimurium delta cya delta crp strains have been shown to provide excellent protection against wild-type Salmonella challenge in chickens. This work describes the construction of a delta cya delta crp derivative of an avian pathogenic S. typhimurium that expresses both the homologous group B determinants (O1,4,5,12) and the heterologous E. coli O78 LPS O antigens. This was accomplished by inserting the E. coli rfb region, which encodes the genes required for O78 expression, into the chromosomal cya gene of S. typhimurium, creating a defined deletion/insertion mutation. A delta crp mutation was introduced in a subsequent step. Expression of both O antigens was stable in vitro and in vivo. Vaccination of white leghorn chicks at day of hatch and 14 days with the recombinant vaccine strain induced serum immune responses against both S. typhimurium and E. coli LPS and protected the birds against subsequent challenge with an avian pathogenic E. coli O78 strain. Introduction of a mutation in rfc, which encodes the O antigen polymerase, reduced the chain length of the S. typhimurium LPS without affecting the expression of O78. The rfc mutation further enhanced the ability of the vaccine strain to protect chickens against E. coli challenge.     

Reciprocal competitive exclusion of salmonella and Escherichia coli by native intestinal microflora of the chicken and turkey

Both the native intestinal microflora of chickens that protected chicks against salmonellae and Escherichia coli and native turkey intestinal microflora were evaluated for their reciprocal protective capacity in both species against Salmonella typhimurium and a pathogenic strain of E. coli. Nalidixic-acid-resistant forms of the S. typhimurium and E. coli strains were used in seeder-bird and individual-bird challenge tests. Reciprocal protection was provided by native chicken and turkey intestinal microflora in chicks and poults against S. typhimurium and the pathogenic strain of E. coli. The chicken and turkey microflora appeared to be equally effective in protecting the two species from S. typhimurium, but protection against E. coli was somewhat greater in the chicken than in the turkey.     

Expression of Escherichia coli antigens in Salmonella typhimurium as a vaccine to prevent airsacculitis in chickens

Avian pathogenic Escherichia coli strains are associated with a variety of extraintestinal poultry diseases, including airsacculitis, colisepticemia, and cellulitis. A number of E. coli serotypes are associated with these diseases, although the most prevalent serotype is O78. Fimbrial proteins expressed by these strains appear to be important virulence factors, including type 1 fimbriae, P fimbriae, and curli. We have been working to develop an effective vaccine to protect chickens against these diseases. We have previously shown that an attenuated Salmonella typhimurium strain expressing O78 lipopolysaccharide provides protection against challenge with an O78 avian pathogenic E. coli strain. In this work, we have constructed an attenuated S. typhimurium that expresses both the O78 lipopolysaccharide and E. coli-derived type 1 fimbriae. In these studies, chickens were vaccinated at day of hatch and again at 2 wk of age. Birds were challenged at 4 wk of age. We found that the vaccine candidate provided significant protection against airsacculitis as compared to untreated controls or birds vaccinated with an attenuated S. typhimurium that did not express any E. coli antigens. In a separate experiment, challenged vaccinates showed significant weight gain compared to challenged nonvaccinates. We were not able to demonstrate protection against E. coli O1 or O2 serotype challenge, nor against challenge with wild-type S. typhimurium.     

Effect of feeding the ionophores monensin and laidlomycin propionate and the antimicrobial bambermycin to sheep experimentally infected with E. coli O157:H7 and Salmonella typhimurium

Escherichia coli O157:H7 and Salmonella are widely recognized as important agents of foodborne disease with worldwide distribution. The use of ionophores in feeding growing ruminants is widespread in the United States and has attracted recent interest due to the apparent temporal relationship between initial ionophore use and the increase in human E. coli O157:H7 cases. Two experiments were conducted to evaluate the effects of short-term feeding of ionophores on fecal shedding, intestinal concentrations, and antimicrobial susceptibility of E. coli O157:H7 and S. typhimurium in growing lambs. Sixteen lambs were used in each experiment, four lambs per treatment group: monensin, laidlomycin propionate, bambermycin, and a control treatment. Lambs were fed a grain and hay (50:50) diet with their respective ionophore for 12 d before experimental inoculation with E. coli O157:H7 or S. typhimurium. Animals were maintained on their respective diets an additional 12 d, and fecal shedding of inoculated pathogens was monitored daily. Lambs were killed and tissues and contents were sampled from the rumen, cecum, and rectum. No differences (P > 0.05) in fecal shedding of Salmonella or E. coli O157:H7 were observed due to treatment. Occurrence of Salmonella or E. coli in luminal contents and tissue samples from the rumen, cecum, and rectum did not differ (P > 0.05) among treatments. Feeding monensin decreased (P < 0.05) the incidence of scours in sheep infected with Salmonella compared with the other treatments. No differences in antimicrobial susceptibility were found in any of Salmonella or E. coli O157:H7 isolates. Results from these studies indicate that short-term ionophore feeding had very limited effects on E. coli and Salmonella shedding or on antimicrobial susceptibility in experimentally infected lambs.     

Serologic survey of slaughter-age ostriches (Struthio camelus) for antibodies to selected avian pathogens

Serum samples from 163 slaughter-age ostriches (Struthio camelus) in Ohio and Indiana were tested for antibodies to avian influenza virus (AIV), Newcastle disease virus (NDV), paramyxovirus (PMV) 2, PMV3, PMV7, infectious bursal disease virus (IBDV), Bordetella avium, Mycoplasma synoviae, Mycoplasma gallisepticum, Ornithobacterium rhinotracheale, Salmonella pullorum, Salmonella gallinarum, and Salmonella typhimurium. One ostrich had antibodies to AIV H5N9, 57% of the ostriches had antibodies to NDV, four ostriches had antibodies to both NDV and PMV2, and one ostrich had antibodies to NDV, PMV2, PMV3, and PMV7. None of the ostriches had antibodies to IBDV, B. avium, M. synoviae, M. gallisepticum, O. rhinotracheale, S. pullorum, S. gallinarum, and S. typhimurium. This is the first report of antibodies to avian influenza and PMV7 in ostriches in the United States.     

Influence of Mycoplasma gallisepticum, infectious bronchitis, and cyclophosphamide on chickens protected by native intestinal microflora against Salmonella typhimurium or Escherichia coli

Chickens that have considerable resistance to Salmonella typhimurium or Escherichia coli infection by early development of a native intestinal microflora shed these bacteria following aerosol exposure to Mycoplasma gallisepticum and/or infectious bronchitis virus. Administration of cyclophosphamide to similarly treated chickens induced slight shedding of these bacteria, and the combination of cyclophosphamide and respiratory agents magnified the shedding rate. These agents also influenced the isolation rate of E. coli and S. typhimurium from the trachea and air sacs.