饲喂侧孢短芽孢杆菌对清远麻鸡生长性能、血清抗氧化指标及肠道微生物的影响

养殖周期相对较长和成本较高是制约清远麻鸡经济效益的关键因素,采用微生物制剂调控清远麻鸡生长性能具有良好的应用前景。该文采用自主选育的侧孢短芽孢杆菌BL01作为微生物态制剂,研究BL01对清远麻鸡生长性能、抗氧化指标及肠道微生物的影响。结果表明：经过30天的饲喂,在饮水中添加BL01能够显著提高清远麻鸡的末重（提高2.7%,P<0.05）和平均日增重（提高2.9%,P<0.05）,降低料重比（降低5.2%,P<0.05）,同时提高了血清总抗氧化酶（total antioxidant capacity,T-AOC）和超氧化物歧化酶活力（superoxide dismutase,SOD）,显著降低了肠道有害菌Eschichia-Shigella（降低15.98%）的比例。以上结果表明饮水添加BL01可以改善清远麻鸡生长性能,增强机体抗氧化能力和调控肠道菌群结构。     

1株短短芽孢杆菌产抗菌物质发酵培养基的优化

本试验分离并鉴定的1株高效短短芽孢杆菌,该菌株产生的抗菌物质能够对大肠杆菌、鸡白痢沙门菌、葡萄球菌及黄曲霉等多种动物致病菌产生拮抗作用。本试验采用Plackett-Burman和最徒抓坡试验对其发酵培养基进行了优化,经验证优化后获得的抗菌物质的效价达到1 229μg/mL,较基础培养基效价提高了57.56%。     

一株凝结芽孢杆菌芽孢抗逆性研究及其产孢条件优化

试验研究一株凝结芽孢杆菌BCRC11592的耐高温、耐酸、耐胆盐及对革兰氏阴性菌抑制的能力,并分析培养时间、温度、初始pH值、接种量和摇床转速等因素对菌体生长和产孢率的影响。结果证实该菌株芽孢有良好的抗逆性,具备开发为微生态饲料制剂的潜力。经优化后其最佳培养条件为培养时间24 h、温度40℃、初始pH值6.5、接种量106cfu、摇床转数140 r/min,在此条件下菌液活菌数为3.5×108cfu/ml,芽孢数为3.0×108cfu/ml,产孢率为85.7%。     

侧孢芽孢杆菌分泌溶菌酶的变化规律及酶学特性分析

试验测定了侧孢芽孢杆菌在不同时间分泌溶菌酶的变化规律,以及不同温度和pH预处理对溶菌酶活性的影响。结果表明,侧孢芽孢杆菌在培养12h时产溶菌酶量最大,溶菌酶活力最高时的温度为33℃,最适pH为5.0。     

1株凝结芽孢杆菌的生物学特性和产芽孢发酵条件研究

试验探索1株凝结芽孢杆菌N1的耐温性能、耐模拟胃液性能、耐胆盐性能、抗生素敏感性、溶血活性等特性,通过单因素试验和正交试验,探索该菌株最优的产芽孢发酵时间、初始pH值、接种量和温度。结果显示,该菌株具有较好的耐温性能、耐模拟胃液性能、耐胆盐性能,对庆大霉素、氯霉素、环丙沙星、红霉素、丁胺卡那、头孢唑林、氨苄西林和青霉素敏感,对复方新诺明、诺氟沙星具有耐受性,无溶血活性。在发酵24 h、初始pH值6.5、接种量5%、温度40℃的条件下,芽孢数为5.13×10^(8)CFU/mL。试验为凝结芽孢杆菌N1的生产、应用提供参考依据。     

日粮添加侧孢短芽孢杆菌可控制鸡舍蝇类繁殖

正采用微生物杀虫剂抑制鸡粪中蝇类发育的关键在于将杀虫剂活性成分与育蝇基质均匀混合才能持续发挥控制效果。意大利萨萨里大学的科研人员通过给笼养鸡口服接种侧孢短芽孢杆菌以了解该细菌对鸡舍蝇类繁殖的影响。结果显示:试验鸡的粪便对成蝇和幼蝇都有毒性作用,杀虫效应存在剂量依赖现象,对成蝇     

枯草芽孢杆菌BS2株和地衣芽孢杆菌BL1株对DDGS发酵条件的优化

试验旨在基于枯草芽孢杆菌BS2和地衣芽孢杆菌BL1的组合作用下对DDGS发酵条件进行优化,以提高DDGS的饲用价值。以DDGS中的醇溶蛋白含量为响应值,通过单因素试验、Plackett-Burman设计、响应面试验等途径对DDGS的发酵条件进行了优化。研究结果表明,当发酵条件为麦麸含量为10%、玉米蛋白粉含量为10%、蔗糖含量为6 mg/kg、KH₂PO₄含量为0.5 mg/kg、FeSO₄含量为0.2 mg/kg、MgSO₄含量为0.1 mg/kg、温度30℃时,发酵48 h后发酵底物中的醇溶蛋白含量最低。利用凯氏定氮仪测量,发酵混合物中醇溶蛋白含量为4.88 mg/100 mL,较优化前12.69 mg/100 mL降低了7.81 mg/100 mL。因此,运用响应面试验预测的该模型有一定的实践指导意义,为后续在DDGS发酵生产中的应用提供理论基础。     

枯草芽孢杆菌GD产脂肽的抗菌作用及活性成分分析

为了考察枯草芽孢杆菌GD菌株代谢产物脂肽对病原菌的作用,采用平板打孔法考察脂肽对病原菌的抑制作用,通过薄层层析色谱(TLC)、高效液相色谱(HPLC)分析对脂肽分离纯化。结果显示,GD菌株产脂肽可抑制病原菌,尤其对鸡源大肠杆菌O2、O78血清型菌株抑制效果明显。电镜结果显示:脂肽破坏大肠杆菌细胞壁,导致菌体死亡。TLC分析发现,GD产脂肽与Surfactin标准品在相同位置上显相同颜色的斑点,说明GD产脂肽可能属于Surfactin类,或是Surfactin同系物。HPLC分析发现,脂肽与标准品Surfactin的色谱峰重叠,保留时间一致;通过样品色谱峰比对得出,脂肽中Surfactin类的比例高达76.34%。试验表明,菌株GD代谢物脂肽具有明显抑制病原菌的作用,脂肽中76%以上为Surfactin类。     

米糠凝集素的部分特性及其抗新城疫病毒作用

采用红细胞凝集试验和观察细胞病变（CPE）的方法分别研究了米糠凝集素的特性和抗病毒作用。结果显示,米糠凝集素能凝集鸡红细胞,促进新城疫病毒对红细胞的凝集,对热有一定的稳定性,耐酸碱;在体外,用米糠凝集素与新城疫病毒作用或用米糠凝集素预处理Vero细胞,均能抑制新城疫病毒在细胞上病变的形成。提示,米糠凝集素具有直接抗新城疫病毒和预防新城疫病毒感染的作用。     

Vaccination against Moroccan strains of Newcastle disease virus

Summary Different vaccination programmes commonly used in Moroccan poultry farms were tested for their capacity to protect chickens against two representative Moroccan strains of velogenic viscerotropic Newcastle disease virus under controlled conditions. All vaccination programmes protected the chickens against mortality and the inactivated vaccine gave the highest antibody titres and the best protection against respiratory symptoms.

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Vacunacion Contra Cepas Marroquies Del Virus De La Enfermedad De Newcastle

Resumen Se ensayaron bajo condiciones controladas, diferentes programas de vacunación para detectar la capacidad de estos de proteger pollos contra dos cepas marroquíes representativas del virus velogénico viscerotrópico de la enfermedad de Newcastle. Todos los programas de vacunación fueron efectivos, protegiendo las aves contra mortalidad. La vacuna inactivada fue la mejor, produciendo los títulos más altos de anticuerpos y protegiendo las aves contra síntomas respiratorios.

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Vaccination Contre Les Souches Marocaines Du Virus De La Maladie De Newcastle

Résumé On a testé différents programmes de vaccination communément mis en oeuvre dans les élevages avicoles du Maroc quant à leur capacité de protéger les poulets vis-à-vis de deux souches marocaines représentatives du virus de Newcastle vélogène-viscérotrope. Les poulets ont été protégés dans tous les programmes de vaccination à l'encontre de la mortalité; le vaccin inactivé confère les plus hauts titres en anticorps et la meilleure protection vis-à-vis des symptômes respiratoires.

     

Protective immunity against Newcastle disease: the role of antibodies specific to Newcastle disease virus polypeptides

Studies were performed to determine if passive immunization with hyperimmune sera generated to specific Newcastle disease virus (NDV) proteins conferred protection against virus challenge. Six groups of 3-wk-old chickens were passively immunized with antiserum against either hemagglutinin-neuraminidase/fusion, (HN/F) protein, nucleoprotein/phosphoprotein (NP/P), Matrix (M) protein, a mixture of all NDV proteins (ALL), intact ultraviolet-inactivated NDV (UVNDV), or negative sera. Blood samples were collected 2 days postimmunization, and the birds were challenged with Texas GB strain of NDV. Antibody titers were detected from those recipient birds that had received the antisera against the HN/F, ALL, or UVNDV by a hemagglutination inhibition test, an enzyme-linked immunosorbent assay (ELISA), and a virus neutralization test. Antibodies were detected only by the ELISA from the birds that had received antisera against NP/P and M protein. Antibody titers in the recipient birds dropped by two dilutions (log2) after 2 days postinjection. Birds passively immunized with antisera against HN/F, ALL, and UVNDV were protected from challenge, whereas chickens passively immunized with antisera against NP/P and M protein and specific-pathogen-free sera developed clinical signs of Newcastle disease. The challenge virus was recovered from the tracheas of all passively immunized groups. The presence of neutralizing antibodies to NDV provided protection from clinical disease but was unable to prevent virus shedding from the trachea.     

Protection conferred by vaccination with Blacksburg and Komarov strains of Newcastle disease virus against Newcastle disease in Bangladesh

Summary An evaluation was undertaken of the efficacy of vaccination of day-old chicks with the Blacksburg (B1) strain of Newcastle disease virus (NDV) followed at various times by vaccination with the Komarov (K) strain. Antibody was detected by the haemagglutination inhibition (HAI) test one week after vaccination with B1 and titres peaked at three weeks and had declined to undetectable levels by nine weeks.After subsequent vaccination with K strain at five, seven or eight weeks of age levels of HAI antibody (titre 80 to 640) were detected after three weeks. Birds vaccinated at seven weeks were tested for antibody and resistance to challenge beyond 19 weeks of age. In this group the HAI titres remained constant (80 to 640) up to 32 weeks of age and then steadily declined to 10 to 20 at 44 weeks of age.A linear relationship between HAI titre and virus neutralising index (VNI) was demonstrated with a range of selected sera. Only birds with an HAI titre of 80 or greater resisted artificial challenge. It is recommended that, following B1 vaccincation at day-old and K vaccination at seven weeks old, revaccination with K strain should be performed at intervals of not more than seven months.

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Proteccion Conferida Mediante Vacunacion Con Las Cepas Blacksburg Komarov Del Virus De Newcastle En Bangladesh

Resumen Se llevó a cabo una evaluación de la eficacia de la vacunación de pollitos de un día, con la cepa Blacksburg (B1) del virus de la enfermedad de Newcastle, seguida de varias aplicaciones vacunales periódicas con la cepa Komarov (K). Se detectaron anticuerpos mediante la prueba de inhibición de la hemaglutinación, una semana después de la vacunación con B1, los títulos alcanzando el pico a las tres semanas y declinaron a niveles no detectables a las nueve semanas.Después de aplicaciones vacunales periódicas con la cepa K, a las cinco, siete u ocho semanas de edad, se detectaron anticuerpos mediante la prueba de inhibición de la hemaglutinación (títulos 80 a 640), después de tres semanas. Las aves vacunadas a las siete semanas, recibieron una descarga y se les hizo prueba de anticuerpos, después de las 19 semanas de edad. En este grupo los títulos de anticuerpos permanecieron constantes (80 to 640) hasta las 32 semanas de edad y después declinaron lentamente a 10 ó 20 a las 44 semanas de edad.Se demostró una relación lineal entre los títulos hallados y el índice viral neutralizante, en un rango de sueros seleccionados. Solamente las aves con títulos de 80 o más altos resistieron la descarga artificial. Se recomienda que, seguidamente a la vacunación con B1 a un día de edad y con K a las siete semanas, las revacunaciones con la cepa K debería hacerse con intervalos de no más de siete meses.

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Protection Conferee Contre La Maladie De Newcastle Au Bangladesh Par La Vaccination A L'Aide Des Souches Blacksburg Et Komarov De Virus De La Maladie De Newcastle

Résumé Une evaluation de l'efficacité de la vaccination de poussins d'un jour à l'aide des souches Blackburg (B1) du virus de la maladie de Newcastle, suivie à différents moments par la vaccination à l'aide de la souche Komarov (K), a été entreprise. Les anticorps furent détéctés par inhibition de l'hemagglutination (HAI), une semaine après la vaccination avec la souche B1 et le titre atteignit un pic à 3 semaines pour décliner jusqu'à des niveaux indétectables à neuf semaines. A la suite de vaccinations consécutives avec la souche K à cinq, sept ou huit semaines, les niveaux d'anticorps HAI furent détectés après trois semaines. Les oiseaux vaccinés à sept semaines furent examinés pour les anticorps et la résistance à une épreuve au delà de 19 semaines d'âge. Dans ce groupe les titres HAI sont restés constants (80 à 640) jusqu'à l'àge 32 semaines, puis ont diminué régulièrement jusqu'à 10 à 20 à l'âge de 44 semaines.Une relation linéaire entre le titre HAI et l'index de neutralisation du virus (VNI) a été démontrée sur une gamme de sérums choisis. Seuls les oiseaux ayant un titre HAI de 80 ou plus ont résisté à l'épreuve artificielle. On recommande que, après une vaccination B1 à un jour, et une vaccination K à l'âge de sept semaines, une revaccination K soit réalisée à des intervalles n'excédant pas sept mois.

     

Vaccination of cyclophosphamide-treated chickens against Newcastle disease virus infection

Newly-hatched chickens were treated with 3 mg of cyclophosphamide (CY) per day for 4 consecutive days. At 2 weeks of age, these chickens, together with a group of untreated controls, were vaccinated intranasally or subcutaneously with the La Sota strain of Newcastle disease virus (NDV). All chickens were challenged intranasally with the GB strain of NDV 2 weeks later. CY-treated, intranasally vaccinated chickens were highly resistant to NDV challenge, yet none of the chickens produced any detectable humoral antibodies to NDV; antibodies to NDV were detectable in the tracheal washings, however.     

Efficacy of a commercial Newcastle vaccine against velogenic viscerotropic Newcastle disease virus.

Effects of parental immunity and method of vaccination were studied in broiler chickens vaccinated with a commercial LaSota vaccine and challenged with the Fontana strain of velogenic viscerotropic Newcastle disease (VVND). Immunity was satisfactory from all methods of vaccination used.     

A comparison of the onset of protection induced by Newcastle disease virus strain B1 and a fowl poxvirus recombinant Newcastle disease vaccine to a viscerotropic velogenic Newcastle disease virus challenge

Four-week-old specific-pathogen-free white rock chickens were immunized with either a commercial recombinant fowl poxvirus-vectored Newcastle disease vaccine (FPN) expressing the hemagglutinin-neuraminidase and fusion protein genes of Newcastle disease virus (NDV) strain B1 or live NDV B1. Vaccinates and controls were challenged by eyedrop and intranasal (E/I) route with a viscerotropic velogenic NDV at 14 days postvaccination to determine the time of clearance of challenge virus. In a subsequent experiment, chickens were challenged at 3, 6, or 10 days postvaccination to determine the onset of immunity. Chickens that received a recommended field dose (1x) or a 0.01x dose of FP-N subcutaneously (s.c.) and were seropositive by hemagglutination-inhibition test at 14 days postvaccination cleared the challenge virus by 14 days postchallenge. Clinical Newcastle disease and high challenge virus titers in tissues were seen only in seronegative FP-N 0.01x dose vaccinates and controls. In a comparison of vaccination with FP-N (1x, 10(4,9) median tissue culture infective dose) s.c., B1 (10(6) median egg infective dose [EID50]) s.c., or B1 (10(6) EID50) E/I, chickens vaccinated at 6 or 10 days before challenge with all vaccines were protected against clinical disease, but only those vaccinated with B1 E/I 10 days before challenge were protected against infection with the challenge virus. Vaccination at 3 days before challenge with B1 E/I provided early protection, but severe nervous signs developed later and reduced overall protection to 60%, whereas disease in chickens vaccinated with B1 s.c. and FP-N s.c. 3 days before challenge was similar to the challenge controls.