Administration of Lactobacillus johnsonii FI9785 to chickens affects colonisation by Campylobacter jejuni and the intestinal microbiota

1. Campylobacter jejuni is the most common bacterial cause of human food-borne gastroenteritis in the world. A major source of human infection is the consumption of contaminated meat, particularly poultry. New control measures to reduce or eliminate this pathogen from the animal gastrointestinal tract are urgently required, and the use of probiotics as competitive exclusion agents is a promising biocontrol measure to reduce C. jejuni in the food chain.

2. In this study, we assessed the potential of Lactobacillus johnsonii FI9785, which has shown efficacy against Clostridium perfringens, to combat C. jejuni. The effect of prophylactic administration of L. johnsonii on the ability of C. jejuni to colonise chickens was determined.

3. Two doses of L. johnsonii given a week apart led to a reduction in C. jejuni colonisation in the caecal contents, but this biocontrol seemed reliant upon a high level of initial colonisation by the probiotic.

4. The microbial composition in the chicken gut was significantly altered by the probiotic treatment, as shown by denaturing gradient gel electrophoresis of 16S rRNA gene amplicons.

5. Together these results demonstrate the potential of this probiotic strain to be tested further as a competitive exclusion agent in poultry against C. jejuni.     

Risk factors for Campylobacter colonization in broiler flocks in Japan

The present study was conducted to estimate the prevalence of and to identify the risk factors for Campylobacter colonization in broiler flocks in Japan. Campylobacter colonization status in flock was evaluated by culturing pooled caecal excrement from 124 broiler flocks. Potential exposure to risk factors was evaluated with a questionnaire for the broiler producers. Odds ratios (ORs) were calculated using a multivariable logistic regression analysis. The prevalence of Campylobacter-positive flocks was 43.5% (upper and lower limits of 95% confidence interval (CI(95%) ): 34.8, 52.3). Multivariable logistic regression model identified two variables as risk factors for Campylobacter colonization. The ORs of Campylobacter colonization were higher in flocks in western Japan (OR=2.68; CI(95%) : 1.04, 6.91) than in eastern Japan, and in flocks supplied with undisinfected drinking water (OR=7.41; CI(95%) : 3.11, 17.66) than in those supplied with disinfected drinking water. These findings indicate that water may play an important role in Campylobacter colonization in broiler flocks in Japan and the use of disinfected water may reduce the risk of Campylobacter colonization.     

Protection of chicks against salmonella infection induced by spray application of intestinal microflora in the hatchery

Summary

The efficacy of spray application of intestinal microflora of the adult bird in protection of broilers against salmonella infections was studied in 3 experiments under laboratory and field conditions.

In chicks treated soon after hatching (in the hatchers at approximately 30 per cent hatch or in the chick delivery boxes in the hatchery) with crop‐caecum homogenate or a mixture of aerobically and strict anaerobically cultured intestinal flora, very good results were achieved.

A very obvious protective effect against a high infection dose (3 × 10 c.f.u. S. infantis bacteria per chick) and complete protection against natural infection with different salmonella types was induced.

A significant improvement of growth rate was observed in broilers treated by spray in the hatchery and reared for 7 weeks under field conditions in an environment heavily contaminated with different salmonella types.     

肉仔鸡腹水综合症的营养调控

本文对肉仔鸡腹水综合症的几种主要诱发因素(包括遗传、饲养环境和饲料营养等)和日粮营养(包括能量、蛋白质和氨基酸、维生素和微量元素、L-肉碱和泛醌等)调控研究进行了综述,重点介绍了L-肉碱或/和泛醌的调控作用可能是通过维持线粒体呼吸链酶活,改善线粒体功能,增强能量代谢和抗氧化功能,从而降低肉仔鸡对腹水综合症的敏感性.     

应用PCR技术检测空肠弯曲菌及结肠弯曲菌的研究

本研究根据空肠弯曲菌及结肠弯曲菌的16s rRNA基因相同保守序列来设计引物,建立了一种PCR检测方法,该方法具有较强的特异性及灵敏性,其对空肠弯曲菌及结肠弯曲菌的最低检测限度为5 CFU/mL,它无需增菌培养过程可以直接对样品进行检验,在对鸡肉样品空肠弯曲菌及结肠弯曲菌的检测中取得了较好的效果.     

辽育白牛与5品种(杂种)肉牛屠宰性能对比试验报告

为了测试辽育白牛的屠宰性能,并与辽宁地区其他主要品种(杂种)肉牛进行比较,辽宁省牛育种中心开展了屠宰试验。试验测得辽育白牛的主要屠宰性能指标为:育肥12个月、育肥16个月时屠宰,宰前活重分别为(561.8±82.1)kg和(664.8±30.5)kg;胴体重分别为(328.9±41.6)kg和(396±20.7)kg;净肉重分别为(278.05±36.7)kg和(339.2±21.9)kg;优质切块重分别为(180.8±23.6)kg和(215.7±15.6)kg;高档牛肉重分别为(50.2±7.4)kg和(58.1±6.7)kg;屠宰率分别为58.6%±1.7%和59.6%±1.4%;胴体产肉率分别为84.5%±1.2%和85.6%±1.4%;净肉率分别为49.5%±1.1%和50.9%±1.8%,优质肉率分别为65.4%±1.4%和63.6%±1.3%;眼肌面积分别为(78±11.2)cm2和(96.4±8.8)cm2;背膘厚分别为(0.65±0.2)cm和(0.73±0.3)cm。结果表明,和其他品种(杂种)肉牛相比,辽育白牛具有较高的屠宰性能指标,并且遗传性能稳定,具备较高的种用价值。     

不同来源锌对肉雏鸡生物效价的研究

以雏鸡对锌的利用率、沉积率和组织中的锌浓度为指标,评定了不同来源的锌(硫酸锌、氧化锌、氯化锌、乙酸锌、硝酸锌、葡萄糖酸锌、小麦麸、米糠、玉米糠、谷糠)的生物效价。结果表明,锌的生物效价不仅与锌的来源、形态有关,而且受饲粮锌水平的影响。无机化合物锌的生物效价均高于植物饲料锌。     

柔嫩艾美耳球虫感染肉鸡后盲肠粘膜iNOS活性变化

本研究旨在探讨肉鸡柔嫩艾美耳球虫 (Eimeria tenella)感染与盲肠粘膜诱生型一氧化氮合酶(inducible nitric oxide synthase,i NOS)活性之间的时间 -效应和剂量 -效应关系。 1日龄黄羽肉鸡 ,在实验室条件下用雏鸡日粮饲养两周后供试。在时间 -效应关系试验中 ,4 5只肉鸡中用 5只鸡作对照 ,其余每只鸡接种 1.0× 10 4 个球虫孢子化卵囊 ,接种前捕杀对照组雏鸡 ,于接种后每 2 4 h分别捕杀 5只 ,取其盲肠粘膜样本 ,按分光光度法检测 i NOS活性 ,连续 8天。试验结果表明 ,与对照组相比 ,肉鸡盲肠组织 i NOS的活性在接种球虫后不同时间明显不同 ,其中接种后第 96 h活性最高 (2 3.70± 7.6 5) ;在剂量 -效应关系试验中 ,4 0只肉鸡以不同的剂量 0、0 .5× 10 4 、1.0× 10 4 、1.5× 10 4 、2 .0× 10 4 、2 .5× 10 4 、3.0× 10 4 、3.5× 10 4 个 /只分别口服接种 ,然后按时间 -效应关系中酶活性最高的时间点取样 ,以同法检测 i NOS活性。试验结果显示 ,接种不同剂量的雏鸡 ,其盲肠组织中 i NOS活性不同 ,与对照组相比各剂量组 i NOS活性均显著增高 (P<0 .0 1) ,在 7个剂量组中 ,以 2 .5× 10 4 个 /只剂量组活性最高 (2 3.37± 8.32 )     

微生物实验室活动中病原外溢风险分析

微生物实验室是进行微生物学研究的重要场所,其建设、使用、运维旨在保护研究人员、环境和社会公众免受潜在生物危害的影响。随着《中华人民共和国生物安全法》的颁布实施,微生物实验室的生物安全管理越来越受到各方重视。在实验室活动中,病原外溢风险是一个备受关注的问题,其重要性不可忽视。围绕微生物实验室常见实验活动,通过存在病原外溢风险的案例分析及风险警示,从实验室设计和建造、实验室安全设施、个人防护和规范操作、废弃物处理和实验器材管理、实验室风险评估、环境监测和应急预案几个方面进行探讨,为有效避免微生物实验室病原外溢提供参考。     

Prevalence of Campylobacter jejuni and its resistance to antibiotics in poultry in the Czech Republic

Thermotolerant Campylobacter spp., in particular Campylobacter jejuni, are among the most frequently identified pathogens, found to be causing human gastrointestinal infections in Europe, with the Czech Republic being no exception. The presented work aimed at assessing results of the first nationwide monitoring of prevalence and antibiotic resistance of Campylobacter spp. in broiler flocks in the Czech Republic, including a comparison of antibiotic resistance of C. jejuni isolates collected from poultry and the human community. The monitoring was carried out in poultry slaughterhouses in 2006 and 2007. From broilers, cloacal swabs were collected and examined. The human isolates of C. jejuni were acquired from rectal swabs in community patients with diarrhoeal diseases. Suspected isolates of both animal and human origin were confirmed by the PCR methods. Antibiotic resistance to selected anti-microbial agents was tested by the microdilution method. In the monitored period, the prevalence of thermotolerant Campylobacter spp. in broilers in the Czech Republic reached almost 50%. In 2006, C. jejuni was detected in 46% and Campylobacter coli in 3% of the tested samples. In 2007, C. jejuni was found in 43% and C. coli in 2% of the samples. The results of anti-microbial susceptibility testing of C. jejuni showed higher resistance in animals when compared with humans. The only exception was tetracycline with higher resistance in isolates of human origin. The highest resistance detected was to quinolone antibiotics. Resistance to oxolinic acid was 77% in animal and 60% in human isolates, to ciprofloxacin 72% in isolates from poultry and 55% in those from humans. In ampicillin, 26% of poultry isolates and 16% of human isolates were resistant. Moreover, 9% of animal isolates demonstrated resistance to streptomycin, undetected in human isolates. In erythromycin, resistance was found in 6% of poultry and 1% of human isolates.     

鸡静注,肌注及内服氟哌酸的药物动力学研究

选用４２只健康ＡＡ鸡，分３组（每组１４只）进行药物动力学研究：静注、肌注及内服的剂量均为１０ｍｇ／ｋｇ。用二氯甲烷提取血浆中的药物，反相高效液相色谱法测定血浆氟哌酸的浓度，测定时以吡哌酸为内标。所得药物一时间数据用ＭＣＰＫＰ计算机程序处理，静注给药拟合二室开放模型，主要动力学参数是：ｔ１／２α０．１４±０．０８ｈ，ｔ１／２β３．６５±１．０３ｈ，Ｋｅ０．８８±０．４０ｈ－１，Ｖｄ３．８１±０．９８Ｌ／ｋｇ，ＡＵＣ１４．１４±３．２９μｇ／ｍｌ．ｈ。内服和肌注给药均适合具有一级吸收二室开放模型，肌注的主要动力学参数是：ｔ１／２ｋａ０．２２±０．１０ｈ，ｔ１／２α１．０３±０．６５ｈ，ｔ１／２β６．８７±２．８６ｈ，Ｋｅ０．２８±０．１０ｈ－１，ＡＵＣ９．８６±２．８８μｇ／ｍｌ．ｈ，Ｆ６９．７８％。内服的主要动力学参数是：ｔ１／２ｋａ０．６９±０．２３ｈ，ｔ１／２α１．７６±０．８９ｈ，ｔ１／２β１０．４３±３．２２ｈ，Ｋｅ０．２１±０．０５ｈ－１，ＡＵＣ８．５６±１．３６μｇ／ｍｌ．ｈ，Ｆ６０．５２％。鸡静注、肌注、内服氟哌酸的药动学特征是吸收较快，在体内分布广泛、半衰期较长。     

Enhancement of enrofloxacin serum antibacterial activity by calcium primed broilers

The aim of this trial was to assess the effect that calcium gluconate priming of 468 broilers has on the antibacterial activity of a standard dose of enrofloxacin. Hence, a series of oral pharmacokinetic studies were carried out in four groups of broilers medicated individually through an oral cannula as follows: group A, medicated only with enrofloxacin 10mg/kg; group B, receiving immediately one after the other, calcium gluconate (200mg/kg) and enrofloxacin 10mg/kg; group C, dosed first with calcium gluconate (200mg/kg) and 1h later enrofloxacin (10mg/kg); and group D, dosed first with calcium gluconate (200mg/kg) and 2h later enrofloxacin (10mg/kg). Broilers were bled at different times after the dose of enrofloxacin and antibacterial activity, measured as concentration of enrofloxacin, was measured by an agar diffusion assay. Results revealed that group D the greatest values of maximum serum concentration (Cs(max)), area under the concentration vs. time curve (AUC) and area under the moment curve (AUMC). These values were statistically higher than the corresponding ones derived from groups A, B and C (P<0.05). Taking Cs(max) and AUC values of group A as reference baseline, an increase of 24% and 50%, respectively, was obtained in group D. Group B had the lowest Cs(max), AUC, AUMC and elimination half life (T(1/2)beta) and these values were statistically different from groups A, C and D (P<0.05). The T(1/2)beta was statistically longer in groups C and D as compared with A and B, and the former groups were also different between each other (P<0.05). These results show that if calcium gluconate is first dosed to broilers and 2h later enrofloxacin is administered (as in group D), a more pronounced antibacterial activity of enrofloxacin can be obtained. A challenge of this sequential dosing scheme in a field trial may reveal its clinical value.     

氯霉素对肉鸡免疫功能的影响

按饲料的0.06％、0.1％、0.15％的比例添加氯霉素、饲喂2～60日龄的肉鸡,虽然对鸡白痢、禽伤寒等疾病有明显的抑制作用,减少死亡率。但对体液、细胞免疫功能、免疫器官、骨髓和红、白血球生成等呈现明显的抑制和损害,本试验初步表明,长期内服氯霉素可引起鸡的慢性应激反应。在正常的饲养条件下,氯霉素对肉鸡的生长增重既没有促进作用,也无明显的抑制现象。根据血液氯霉素浓度的测定表明,防治鸡疾病,饲料添加0.06％的氯霉素是有效的、毒性相对较小的剂量,但也不应长期服用。     

肉用仔鸡对甲硫亚砜生物学利用性的研究

选用459只1日龄Arbor Acres混合雏进行比较饲养试验,以研究肉仔鸡对甲硫亚砜的生物学利用性。试验期6周。采用玉米-花生饼-血粉基础日粮,在前(1～3周)、后(4～6周)期,其营养水平分别为:代谢能3.02、3.05Mcal/kg;粗蛋白21.6、19.0％;蛋氨酸十胱氨酸0.64、0.59％,且以蛋氨酸为限制因素。饲喂基础日粮组为对照组,前、后期分别以0.12％、0.05％作为添加递增梯度向基础日粮添加DL-蛋氨酸(M1、M2、M3、M4)或DL-甲硫亚砜(S1、S2、S3、S4)。试验结果表明: 1.当日粮胱氨酸适宜并仅以蛋氨酸为限制因素时,DL-甲硫亚砜在促进肉鸡生长上与DL-蛋氨酸具有相似的作用,且随着甲硫亚砜或蛋氨酸的逐级添加,肉鸡腹脂百分率有下降的趋势。 2.在本试验条件下,日粮中的蛋氨酸水平对1～3周龄与4～6周龄肉仔鸡分别以0.48％和0.32％为宜。过量的蛋氨酸对肉鸡生长有不利影响,而甲硫亚砜则无。     

去毒桐籽粕饲用价值的探讨

桐籽粕含有多种醇、二萜脂等有毒物质,因而长期以来只能用于肥料。桐籽粕中含代谢能5.46MJ/kg,粗蛋白质约36.13%,赖氨酸1.43%及较多的铁。小白鼠、肉用仔鸡饲养试验及屠宰测定试验表明:在肉用仔鸡前期日粮中加入5%～8%的桐籽粕,虽然略逊于优质蛋白质饲料,但作为中、低档蛋白质饲料资源,仍具有开发价值。     

维生素C对热应激状态下肉仔鸡生产性能及维生素C合成能力的影响

选用21日龄AA肉仔鸡240只,研究了热应激（室温32－35℃,相对湿度80％－825）和非应激（室温20－25℃,相对湿度65％－70％）状态下日粮添加维生素C对肉仔鸡生产性能和体内维生素C合成能力的影响。试验结果表明,肉仔鸡在应激状态下血浆维生素C含量降低,日粮补充200mg/kg维生素C可以明显提高血浆维生素C含量。热应激导致肉仔鸡肝脏维生素C合成关键酶－古洛糖酸内酯氧化酶活性明显降低,使维生素C含量。热应激导致肉仔鸡肝脏维生素C合成关键酶－古洛糖酸内酯氧化酶活性明显降低,使维生素C的合成能力减弱,日粮汪厍维生素C可提高应激状态下肉仔鸡肝脏古洛糖酸内酯氧化酶活性,随肉仔鸡日龄的增加,肉仔鸡肝脏古洛糖酸内酯氧化酶活性有上升趋势,表明维生素C合成能力随日龄的增加逐渐提高。