野猪粪便中乳酸菌的分离鉴定及特性研究     

王翌  李淼  李永锋  孙元  仇华吉 《中国农业科学》2020,53(14):2964-2973

【目的】筛选安全的、具有优良特性的乳酸菌菌株,进一步研发益生制剂,为饲料添加剂等动物相关产品提供资源。【方法】从我国黑龙江省大兴安岭地区采集野猪粪便样品13份,编号后置于4℃保温箱迅速运回实验室,利用MRS培养基分离纯化乳酸菌。使用细菌基因组DNA提取试剂盒提取分离菌株的基因组DNA,利用细菌16S rDNA通用引物进行PCR鉴定,将扩增得到的序列测序后在NCBI上使用BLAST与GenBank数据库中序列进行对比分析,确定各菌株的分类学地位。将鉴定后的乳酸菌菌株分别接种于酸性（pH 3.0）和含胆盐（0.3%）的MRS培养基,在不同条件下评价乳酸菌菌株的耐酸、耐胆盐特性。将过夜培养的乳酸菌于室温条件下静置,在不同时间测定其OD_600nm,进行自凝集能力评价;过夜培养的菌株分别与致病性埃希氏大肠杆菌、金黄色葡萄球菌和鼠伤寒沙门氏菌3种致病菌混合后于室温静置,进行共凝集能力检测。在体外,分别进行乳酸菌菌株对Caco-2细胞和IPEC-J2细胞的黏附能力测定,评价不同菌株的黏附能力。通过测定乳酸菌菌株对致病性埃希氏大肠杆菌、金黄色葡萄球菌和鼠伤寒沙门氏菌3种致病菌的抑菌环直径,评价分离菌株的抑菌活性。通过体内外试验评价乳酸菌菌株的安全性。在体外,分别以模式菌株嗜酸乳杆菌和金黄色葡萄球菌作为阴性对照和阳性对照,将3株乳酸菌菌株和对照菌株在血平板上划线,37℃厌氧孵育18—24 h,观察细菌菌落周围是否形成溶菌环,评价分离菌株的溶血特性。使用文献中已报道的毒力因子引物对分离的乳酸菌菌株进行PCR扩增,检测是否存在毒力因子的编码基因,评估分离菌株的安全性。在体内,将过夜培养的乳酸菌连续饲喂7周龄的BALB/c小鼠21 d,分别测定小鼠的初始体重和最终体重,观察计算体重变化情况;饲喂21 d后,解剖获取小鼠的脾脏、肝脏和肾脏计算器官指数,评价分离乳酸菌菌株的体内安全性。【结果】从野猪粪便中分离得到3株对酸和胆盐具备一定耐受力的乳酸菌,经鉴定分别为蒙氏肠球菌（Enterococcus mundtii）、耐久肠球菌（Enterococcus durans）和黏膜乳杆菌（Lactobacillus mucosae）。3株乳酸菌菌株均表现出较强的自凝集能力和对致病菌的共凝集能力,同时对Caco-2细胞和IPEC-J2细胞均表现出较强的黏附能力,抑菌试验结果显示黏膜乳杆菌对3种致病菌均具备较强的抑菌活性。经体内外安全性评价,3株乳酸菌菌株无溶血性,且均未检测到毒力基因,经其连续饲喂的小鼠行为表现正常、状态良好,其中,与对照组相比,黏膜乳杆菌饲喂后小鼠增重显著。【结论】从大兴安岭野猪粪便中分离的3株乳酸菌（特别是黏膜乳杆菌）具有良好的特性和安全性,具备进一步开发益生菌制剂的潜力。  相似文献   

华北山地阳坡中生灌草植被对CO2浓度和温度变化的光合响应     

林栋  吕世海  冯朝阳  马晖玲  刘立成  赵小强 《草业科学》2008,25(4):135-140

利用便携式光合气体分析系统(LI-6400),从全球变化的角度分析华北山地阳坡灌草植被群落中5种具有代表性的植物光合特征对CO2浓度和温度变化的响应.结果表明:随着温度的升高,狗尾草Setaria viridis和龙牙草Agrimonia pilosa净光合速率呈明显增大趋势,在华北山地阳坡灌草群落中具有较强的竞争力,而达乌里胡枝子Lespedeza davurica的净光合速率对CO2的响应值降低,在环境温度升高的条件下不利于其光合产物的积累.  相似文献   

Plasma glucose concentration is maintained during TSE infection of cattle and sheep     

Horton RA  Allison GG  Jayasena D  Stevens PR  Clifford D  Everest S  Jackman R  Moorby JM 《Veterinary research communications》2008,32(2):193-199

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Towards a risk-based surveillance for Trichinella spp. in Danish pig production     

Alban L  Boes J  Kreiner H  Petersen JV  Willeberg P 《Preventive veterinary medicine》2008,87(3-4):340-357

Increasing demands for cost-effectiveness in surveillance for human health hazards from animal origins can be met by introducing risk-based principles. This e.g. implies targeting subpopulations with higher risk of infection compared to the whole population. Furthermore, historical data from surveillance can be collated and used to assess future risk of infection. To demonstrate the effectiveness of combining these two approaches, we used a model called “Discounting historical evidence”. It depends mainly on the annual risk of introduction (PIntro) and the surveillance system sensitivity (SSe) (ability to detect infection if present). The model implies simulations that reiterate for a number of years. For each year the output is updated with the confidence on absence in infection. Trichinella spiralis infection in pigs is used as an example. In Denmark, more than 20 million pigs are tested annually. Despite more than 70 years of testing no pigs have been found positive for Trichinella. Hence, PIntro is low. SSe can be estimated from the maximum number of infected carcasses expected under the specified design prevalence, and the sensitivity of the test applied. According to our assessment, the current prevalence of Trichinella in Danish pigs is less than one case per million, which we interpret as negligible risk. Based on this, a risk-based surveillance programme for Trichinella is designed that targets all out-door reared pigs as well as all sows and boars (current total 610,000 slaughtered annually). These subpopulations are judged to have higher risk of getting Trichinella. Again, SSe and PIntro are estimated and the model results show that risk-based surveillance can be applied without jeopardizing human health. Finally, we incorporate wildlife surveys and test quality assurance in the programme. The results of the simulation model were included in an application to the European Commission concerning Denmark's status as a region with negligible risk of Trichinella. In July 2007, the European Commission granted status as “negligible risk” to Danish pigs and pork.  相似文献   

动物性食品中抗菌药物残留检测方法研究进展     

刘丁溪  杨杰程  周宏超  郭抗抗 《中国畜牧兽医》2019,46(7):2183-2192

抗菌类药物在预防、治疗动物疾病中发挥了重要的作用,但不规范用药、超剂量用药甚至滥用,使动物性食品中抗菌类药物残留问题日益突出,引起人们的广泛关注。对动物性食品中抗菌类药物残留的检测是判定其安全性的重要内容,根据检测的目的和需要,可将检测方法分为现场检测和实验室检测。胶体金免疫层析法是目前使用最广的现场检测方法;实验室检测方法众多,又可分为抗菌类药物残留的定性检测法和定量检测法,前者主要包括2,3,5-三苯基氯化四氮唑法（TTC法）、纸片法（PD法）、活性检测法等,后者主要包括高效液相色谱法、液相色谱-质谱联用法、超高效液相色谱-质谱联用法、毛细管电泳法、生物传感器法和免疫分析法等,可满足不同检测目的和实验条件的需要。作者对肉、蛋、奶中抗菌类药物残留的现场检测和实验室检测技术进行了总结,为更进一步研究快速、敏感、高通量、成本低廉的食品中抗菌类药物残留检测方法奠定理论基础。  相似文献   

Effect of contrast media formulation on computed tomography angiographic contrast enhancement.     

Miori Kishimoto  Kazutaka Yamada  Ryo Tsuneda  Junichiro Shimizu  Toshiroh Iwasaki  Yoh-Ichi Miyake 《Veterinary radiology & ultrasound》2008,49(3):233-237

The characteristics of contrast media formulation (mgI/ml, osmolarity, and viscosity) are generally not considered important in computed tomography (CT) angiography in animals. The purpose of this study was to assess the contrast effect in CT angiography as a function of contrast media formulation, with a constant iodine dose. The contrast effects of three contrast media with different iodine concentrations were compared by administering identical iodine dosages (mgI/kg). The contrast effects of the three contrast media differed, and the area under the time-attenuation curve of iohexol 350 mgI/ml, which had the highest iodine concentration, was the lowest. It was hypothesized that the contrast effect of a contrast medium decreases with higher iodine concentration because of the high amount of residual iodine present in the circulatory system from the injection site to the portion immediately before the great vessels. In addition, the influence of osmotic dilution on contrast media with high osmolarity was also considered. In conclusion, the contrast effect varies with different contrast media formulations, even when the same iodine dosage is administered.  相似文献   

Effects of a low dose infusion of racemic and S-ketamine on the nociceptive withdrawal reflex in standing ponies     

Peterbauer C  Larenza PM  Knobloch M  Theurillat R  Thormann W  Mevissen M  Spadavecchia C 《Veterinary anaesthesia and analgesia》2008,35(5):414-423

ObjectiveTo investigate the effect of plasma concentrations obtained by a low dose constant rate infusion (CRI) of racemic ketamine or S-ketamine on the nociceptive withdrawal reflex (NWR) in standing ponies.Study designProspective, blinded, cross-over study.AnimalsSix healthy 5-year-old Shetland ponies.MethodsPonies received either 0.6 mg kg⁻¹ racemic ketamine (group RS) or 0.3 mg kg⁻¹ S-ketamine (group S) intravenously (IV), followed by a CRI of 20 μg kg⁻¹minute⁻¹ racemic ketamine (group RS) or 10 μg kg⁻¹minute⁻¹ S-ketamine (group S) for 59 minutes. The NWR was evoked by transcutaneous electrical stimulation of a peripheral nerve before drug administration, 15 and 45 minutes after the start of the bolus injection and 15 minutes after the end of the CRI. Electromyographic responses were recorded and analysed. Arterial blood was collected before stimulation and plasma concentrations of ketamine and norketamine were measured enantioselectively using capillary electrophoresis. Ponies were video recorded and monitored to assess drug effects on behaviour, heart rate (HR), mean arterial blood pressure (MAP) and respiratory rate.ResultsThe NWR was significantly depressed in group RS at plasma concentrations between 20 and 25 ng mL⁻¹ of each enantiomer. In group S, no significant NWR depression could be observed; plasma concentrations of S-ketamine (9–15 ng mL⁻¹) were lower, compared to S-ketamine concentrations in group RS, although this difference was not statistically significant. Minor changes in behaviour, HR and MAP only occurred within the first 5–10 minutes after bolus drug administration in both groups.ConclusionAntinociceptive activity in standing ponies, demonstrated as a depression of the NWR, could only be detected after treatment with racemic ketamine. S-ketamine may have lacked this effect as a result of lower plasma concentrations, a more rapid metabolism or a lower potency of S-ketamine in Equidae so further investigation is necessary.  相似文献   

Use of the advanced micro-osmometer model 3300 for determination of a normal osmolality and evaluation of different formulas for calculated osmolarity and osmole gap in adult dogs     

James W. Barr III  DVM    S. Anna Pesillo-Crosby  VMD  DACVECC 《Journal of Veterinary Emergency and Critical Care》2008,18(3):270-276

Objective: To determine a reference interval of whole blood and plasma osmolalities for dogs using the Advanced Micro Osmometer Model 3300, to compare calculated osmolarity to measured osmolality, to determine a reference osmole gap, and to determine the best formula for calculated osmolaity. Design: Prospective, observational. Setting: Tertiary referral and teaching hospital. Animals: One hundred healthy adult dogs. Interventions: None. Measurements: Serum and whole blood biochemistry and osmolality assessments. Results: The mean and median of the measured whole blood osmolality were 323 and 320 mOsm/kg, respectively, with a standard deviation of 13.2 mOsm/kg. The mean and median of the measured plasma osmolality were 313 and 310 mOsm/kg, respectively, with a standard deviation of 13.2 mOsm/kg. The formula that was closest to predicting the measured whole blood and plasma osmolality was ((1.86(Na+K))+(BUN/2.8)+(Glucose/18))/0.93 followed closely by the traditional formula of (2(Na+K))+(BUN/2.8)+(Glucose/18). The mean calculated osmolarities using these formulas were 314.1 and 313.25 mOsm/L, respectively. The mean osmole gap using these formulas was 3.49 and 4.41 mOsm, respectively, for whole blood and ?2.01 and ?1.1 mOsm, respectively, for plasma. Conclusion: The Advanced Micro Osmometer Model 3300 was successful in measuring the osmolality in relative agreement with the current published reference intervals for osmolality. Measured osmolality correlated well with traditional calculated osmolarity.  相似文献   

饲料产业的环保问题及解决对策     

李超显 《中国饲料》2019,(18):114-117

在过去较长的时间段里,一些畜牧养殖业为了追求规模和经济效益,选择以牺牲环境为代价的生产管理模式。该模式虽然在短期内可以达到明显成效,但其带来的环境污染、食品安全、价格持续走低等问题日益显现,对畜牧养殖业健康、可持续发展形成威胁和挑战。饲料与食品均为可食之物,两者无明显界定,如小麦、玉米等即可作为动物饲料,又可以作为食品,而且诸多食品又来源于动物组织以及蛋和奶。所以,饲料产业与环境、食品安全息息相关。为便于论述,笔者从畜牧养殖业的角度来对饲料产业的环保问题及解决对策做出分析,为有关企业、部门提供参考。  相似文献   

Validation of a portable device (iSperm®) for the assessment of stallion sperm motility and concentration     

Pouya Dini  Lucas Troch  Isabel Lemahieu  Peter Deblende  Peter Daels 《Reproduction in domestic animals》2019,54(8):1113-1120

The objective of this study was to evaluate the accuracy of a novel, portable device (iSperm^® Equine for assessing concentration and motility of stallion semen). In the first experiment, semen concentration was determined by the iSperm^® Equine (Aidmics Biotechnology), Androvision^® (Minitube) and NucleoCounter^® SP‐100? (ChemoMetec). The total motility and progressive motility were determined by the iSperm^® Equine and the Androvision^® using the manufacturer's guidelines. Frozen/thawed semen samples (n = 33) at various dilutions were analysed for concentration and motility with the above‐mentioned devices. There was a significant correlation between the concentrations measured with iSperm^® and NucleoCounter^® at all the measured dilutions. Moreover, <10% difference in concentrations was observed between the iSperm^® and NucleoCounter^® using the Bland–Altman test. There was also a significant correlation between iSperm^® and Androvision^® for total and progressive motility. In the second experiment, the parameters used in the Androvision^® were modified to match those of the iSperm^®. Total motility and progressive motility of frozen/thawed semen samples (n = 10) were determined, and the similarity between the Androvision^® and iSperm^® was confirmed by correlation studies and Bland–Altman test. The results of these experiments demonstrate that the iSperm^® offers a reliable and practical alternative for the semi‐automated measurement of concentration and motility of stallion semen in the field. The iSperm^® enables the practitioner to obtain objective and repeatable measurements on a variety of semen types (fresh, cooled and frozen) in the field at the time of insemination and thus acquire more insight into the quantity and quality of the provided insemination doses. This mare‐side diagnostic tool may help practitioners in identifying presumed subfertility problems more rapidly and act accordingly.  相似文献