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1.
中链脂肪酸甘油酯已经成为抗生素替代物研究的新热点。文章旨在探究月桂酸、单辛酸甘油酯、单月桂酸甘油酯、辛葵酸甘油酯对大肠埃希菌、金黄色葡萄球菌、肠炎沙门氏菌和鸡白痢沙门氏菌的抑菌效果。结果显示:月桂酸、单月桂酸甘油酯、单辛酸甘油酯对大肠埃希菌有显著(P<0.05)抑制作用;月桂酸、单月桂酸甘油酯、单辛酸甘油酯、辛葵酸甘油酯对金黄色葡萄球菌有显著(P<0.05)抑制作用;月桂酸、单月桂酸甘油酯、单辛酸甘油酯、辛葵酸甘油酯对肠炎沙门氏菌有显著(P<0.05)抑制作用;月桂酸、单月桂酸甘油酯、单辛酸甘油酯对鸡白痢沙门氏菌有显著(P<0.05)抑制作用。其中,月桂酸、单月桂酸甘油酯、单辛酸甘油酯对4种致病菌的作用效果随时间延长而增强。  相似文献   
2.
陈维  谭涛 《猪业科学》2021,38(8):42-45
为了促进食品安全和养猪业的健康发展,禁止在饲料中使用促生长抗生素势在必行。随着我国的饲料禁抗相关法规的推行,饲料企业被严格禁止在饲料生产过程中加入抗生素,这也导致了猪场疾病尤其是肠道疾病的高发,而仔猪肠道发育未完全,免疫系统未发育成熟,更容易发生严重的腹泻甚至死亡。文章对几种常见的仔猪细菌性腹泻疾病进行了回顾,病原包括大肠杆菌、沙门氏菌、魏氏梭菌,讨论了它们的临床症状与防控措施,为猪场在防控这些细菌性腹泻提供参考。  相似文献   
3.
旨在探明发酵饲料对肉鸡抗沙门氏菌感染的影响。将50只1日龄中速黄羽肉鸡随机分为5个处理组,对照组、模型对照组饲喂基础饲粮(基础日粮+10%未发酵饲料),抗生素对照组在基础饲粮中添加20 mg·kg-1硫酸粘杆菌素,5%发酵组、10%发酵组分别用5%、10%发酵饲料替代基础饲粮中的未发酵饲料。肉鸡13日龄时,对照组连续2 d口腔灌服400 μL无菌水,其他组连续2 d口腔灌服400 μL沙门氏菌液(1×109 CFU·mL-1)。肉鸡15日龄时进行屠宰,取血清测定促炎因子(IL-1β、IL-6、TNF-α)、内毒素(LPS)、D-乳酸(D-LA)水平,取结肠进行HE染色观察结肠形态,取结肠黏膜测定TLR4路径关键信号分子的基因表达量。结果表明,沙门氏菌感染导致肉鸡血清促炎因子(IL-1β、IL-6、TNF-α)水平显著上升,TLR4信号通路中的关键信号分子(TLR4、MyD88、TRAF6、NF-κB)mRNA相对表达量显著上升,血清LPS、D-LA水平显著上升,而抗生素组、5%发酵组、10%发酵组的这些指标均有不同程度的改善,表明多菌种联合发酵饲料能够改善沙门氏菌感染导致的炎症反应和肠道屏障受损,效果接近20 mg·kg-1硫酸粘杆菌素。  相似文献   
4.
旨在解决印第安纳沙门菌传统检测方法的缺陷,建立快速、特异、灵敏的分子检测方法。通过比较基因组学方法获取印第安纳沙门菌特异性检测靶标,进一步设计用于环介导等温扩增的引物组。通过对反应条件优化,建立针对印第安纳沙门菌的特异性分子检测方法。结果显示,该检测方法特异性强、耗时短,检测下限为59拷贝·反应-1。应用该方法对临床分离菌株进行检测,结果不仅与国家标准(GB4789.4—2016)检测结果一致,还可用于自凝菌株检测。本研究建立的方法能实现印第安纳沙门菌的快速检测,将在临床诊断中发挥重要作用。  相似文献   
5.
鼠伤寒沙门菌烈性噬菌体的分离鉴定与生物学特性   总被引:2,自引:2,他引:0  
旨在分离鼠伤寒沙门菌烈性噬菌体,为控制该病原菌感染或污染提供生物制剂。以1株从市售散装牛奶中分离到的多重耐药性鼠伤寒沙门菌为宿主菌,采用人工诱导方法,连续1周每日给3只试验鸡饲喂宿主菌悬液,7 d后,采用双层琼脂平板法从试验鸡粪便中分离培养噬菌体,并对其效价、核酸类型、宿主谱、热稳定性与酸碱耐受性以及对鼠伤寒沙门菌感染小鼠的治疗效果进行分析。结果表明:分离到1株鼠伤寒沙门菌噬菌体,命名为KM104。该病毒在体外高效裂解同源宿主菌株及另1株受试鼠伤寒沙门菌,形成清晰透明、直径约1 mm圆形噬菌斑,核酸类型为DNA,基因组约为28 kb,最佳感染比(MOI)为1∶10,对宿主菌感染的潜伏期约为6 min,70 min时效价最高,达4.6×108 PFU·mL-1,在20~60℃、pH2.0~8.0范围内保持较高的生物学活性,并有效减轻鼠伤寒沙门菌引起的小鼠十二指肠组织损伤。结果提示,噬菌体KM104能在体内外高效裂解鼠伤寒沙门菌,且增殖迅速,对环境适应性强,其耐酸特性利于抵御胃酸的分解,具有应用于生物防治的潜力。  相似文献   
6.
基于“食品质量与安全控制”课程的理论性和应用性特点,结合案例教学在趣味性、互动性、分析解决问题等方面的优势,以2000—2004年美国加州巴旦木(Almonds)出现的致病菌污染、流行病学溯源、全产业链应对措施及效果为实际案例,把生物性危害因素、食品安全溯源、食品安全控制体系等教学内容串联起来,通过资料查阅、小组讨论、分组汇报和答辩、集中讨论及总结、教学反馈等环节进行教学方法的改革,从而提高教学质量。  相似文献   
7.
2015—2017年新疆动物源鼠伤寒沙门菌耐药性分析   总被引:1,自引:1,他引:0  
为完善新疆动物源鼠伤寒沙门菌耐药的相关数据,为多重耐药病源菌的防控提供依据,本研究检测了2015—2017年新疆不同动物源鼠伤寒沙门菌的流行情况、耐药特性及耐药基因携带率。对经选择性培养基和特异性PCR鉴定的不同动物源鼠伤寒沙门菌,通过琼脂稀释法进行环丙沙星等12种抗菌药物的最小抑菌浓度测定,同时采用PCR方法测定耐药基因在鼠伤寒沙门菌中的携带情况。结果表明:从不同动物中共分离获得162株鼠伤寒沙门菌,分离率由高到低依次为宠物(犬和猫)、猪、羊、牛和鸡;药敏试验显示,不同动物源鼠伤寒沙门菌对环丙沙星、氨苄西林、四环素和氟苯尼考的耐药率80.0%,未检出对阿米卡星和磷霉素耐药的耐药菌株。从不同动物源分离的162株鼠伤寒沙门菌中有159株菌为多重耐药菌株,占98.1%;不同动物源鼠伤寒沙门菌多重耐药均以CIP-AMP-TET-FFC-SMZ 5耐谱型为主。经耐药基因分析,不同动物源鼠伤寒沙门菌耐药基因检出率为6.8%~97.4%,未检出blaSHV、qnrD、rmtB和mcr-1基因。综上,鼠伤寒沙门菌在新疆不同动物中流行率高,耐药现象严重,多重耐药菌株较多且耐药基因携带率高,部分不同动物源菌株间具有相同的耐药表型和耐药基因型。应加强畜牧业抗菌药物使用的管理制度,进而控制鼠伤寒沙门菌耐药性的发展趋势。  相似文献   
8.
This study aimed to provide new insights into the epidemiology of Salmonella in pig production, focusing on potential shedding patterns in breeding pigs throughout a full production cycle and the risk of transmission of infection from the sow to her offspring. A longitudinal study was conducted on five farrow‐to‐finish commercial pig farms. In each herd, shedding of Salmonella in faeces was monitored in breeders through service, gestation and lactation. Swabs of the farrowing room floor and pools of faeces from piglets were collected on two occasions during lactation. Environmental pen swabs were also taken in the weaning and finisher houses. Salmonella isolates were serotyped, tested for antimicrobial resistance (AMR) and typed by Multiple‐Locus Variable number tandem repeat Analysis (MLVA). Shedding by breeding pigs was low in all stages of the production cycle; 5% of sows shed at service, the production stage with highest risk of shedding (p < .01), 1.6% shed during gestation and 2.5% after farrowing. Salmonella was detected in 4% of piglet faecal pools in the second week post‐farrowing and 5% in the fourth week. Serotyping and AMR profiles of Salmonella isolates revealed that strains in sows and gilts were mostly different from strains isolated in weaner and finisher facilities. MLVA typing confirmed that the source of infection in piglets was in most instances the contaminated environment rather than their dam. Based on the typing results, it appears that sows do not pose a major risk in the maintenance and transmission of Salmonella to their progeny but instead the contaminated pen environment is more significant in the perpetuation of the organism on farm.  相似文献   
9.
Salmonella Dublin is strongly adapted to cattle causing enteritis and/or systemic disease with high rates of mortality. However, it can be sporadically isolated from humans, usually causing serious disease, especially in patients with underlying chronic diseases. The aim of this study was to molecularly type S. Dublin strains isolated from humans and animals in Brazil to verify the diversity of these strains as well as to ascertain possible differences between strains isolated from humans and animals. Moreover, the presence of the capsular antigen Vi and the plasmid profile was characterized in addition to the anti‐microbial resistance against 15 drugs. For this reason, 113 S. Dublin strains isolated between 1983 and 2016 from humans (83) and animals (30) in Brazil were typed by PFGE and MLVA. The presence of the capsular antigen Vi was verified by PCR, and the phenotypic expression of the capsular antigen was determined serologically. Also, a plasmid analysis for each strain was carried out. The strains studied were divided into 35 different PFGE types and 89 MLVA‐types with a similarity of ≥80% and ≥17.5%, respectively. The plasmid sizes found ranged from 2 to >150 kb and none of the strains studied presented the capsular antigen Vi. Resistance or intermediate resistance was found in 23 strains (20.3%) that were resistant to ampicillin, ciprofloxacin, chloramphenicol, imipenem, nalidixic acid, piperacillin, streptomycin and/or tetracycline. The majority of the S. Dublin strains studied and isolated over a 33‐year period may descend from a common subtype that has been contaminating humans and animals in Brazil and able to cause invasive disease even in the absence of the capsular antigen. The higher diversity of resistance phenotypes in human isolates, as compared with animal strains, may be a reflection of the different anti‐microbial treatments used to control S. Dublin infections in humans in Brazil.  相似文献   
10.
1. An experiment was conducted to compare the natural resistance of an indigenous breed of local village chickens to Salmonella gallinarum with two commercial breeds: ISA Brown and ISA White layers under experimental conditions.

2. A total of 72 chickens from each of these breeds were randomly distributed to 4 pens to provide equal numbers of two replicate pens maintained as infected and control (uninfected). All chickens in infected groups were inoculated orally with 1 × 108 CFU (1 ml dose) of a field isolate of S. gallinarum, at the age of 8 and 16 weeks given over 5 consecutive days. Growth performance, clinical signs, gross pathological lesions and antibody responses were measured.

3. A significantly higher mortality was observed in the brown layers compared with the white layers, and clinical signs and mortality were absent in village chickens. However, a large number of birds with gross lesions and high antibody titres were detected in village chickens, indicating that birds had the disease subclinically. Commercial breeds had a significantly higher body weight, feed intake and feed conversion efficiency.

4. There was a significantly lower proportion of positive reactors in village chickens in the whole-blood agglutination test (35%) compared to brown (100%) and white (90%) layers even after the second inoculation. Uninfected birds were negative in all groups. The indirect enzyme-linked immunosorbent assay confirmed these observations.

5. These results suggest that the indigenous breed had superior natural resistance to S. gallinarum than the commercial breeds.  相似文献   

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