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β防御素是猪体内分泌的一类抗菌肽,广泛分布于各个组织中,在抵抗病原入侵和免疫调节中发挥着重要作用。猪β防御素对细菌、真菌和病毒都有很强的杀灭作用,并且具有分子量小、热稳定性好、无残留等优点,是理想的抗生素替代品。研究表明,猪β防御素的表达与个体抗病力正相关,增加内源性防御素表达或直接摄入外源性防御素均能增强机体免疫力并促进生长。脂肪酸、氨基酸、维生素、益生菌、病原微生物等外源刺激皆可影响β防御素的表达。随着防御素相关研究的深入,将有望解决养猪生产中长期使用抗生素而导致的耐药性、药物残留及环境污染等问题。文章介绍了猪β防御素的结构特征、表达特异性及生物学功能,主要综述了外源刺激对β防御素表达的影响及其作用机制,初步说明外源β防御素作为饲料添加剂在仔猪生产中的效果,旨在为猪β防御素的深入研究及其在生猪健康养殖中的应用提供参考。 相似文献
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防御素是广泛分布于脊椎动物体内的高度保守的小型阳离子肽,具有抵抗病原微生物的能力,并在先天性免疫与适应性免疫中发挥重要作用。猪β-防御素129(Porcine β-Defensin 129,pBD129)和猪β-防御素114(Porcine β-Defensin,pBD114)广泛分布于猪的各个器官和组织中,它们除抵抗病原微生物、调节机体免疫功能外,还对猪的繁殖与发育具有重要作用。近年来研究表明,pBD129和pBD114在公猪附睾中有较高的表达量,并参与精子的成熟、运动和受精过程,对雄性动物的精子功能和受精能力具有重要影响。本文对pBD129和pBD114在猪体内的表达分布情况、参与调节的信号通路以及相关生物学功能等进行综述,旨在为pBD129和pBD114的功能研究和应用提供理论和参考依据。 相似文献
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随着抗生素在饲料产业中的全面禁用,如何在后抗生素时代中保证动物的高效生产成为当前饲料行业的主要任务。防御素作为一类重要的免疫调节分子,是机体防御体系的重要组成部分。越来越多的证据表明,防御素参与并调控动物肠道的微生态平衡,而后者常被认为是决定高效生产中饲料养分沉积与转化的关键。因此,全面了解防御素的作用机制及其参与动物肠道稳态调节的作用显得尤为重要。文章介绍了防御素的来源、功能及作用机制,并着重分析防御素在增强肠道屏障功能、促进肠道黏膜免疫反应以及调控肠道微生物菌群的作用,以期为防御素在动物生产中的应用提供理论指导和依据。 相似文献
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β-防御素(beta-defensian,BD)在哺乳动物雌性生殖系统中广泛表达,在免疫、预防生殖道感染及胎儿正常发育等方面起到重要作用。主要对哺乳动物β-防御素在哺乳动物雌性生殖系统组织中的分布、作用及其调控进行了综述,并对其应用前景进行了展望,以期更好地揭示β-防御素在雌性生殖系统中的影响,从而为β-防御素的进一步研究提供理论依据。 相似文献
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β-防御素(beta-defensian,BD)在哺乳动物雌性生殖系统中广泛表达,在免疫、预防生殖道感染及胎儿正常发育等方面起到重要作用。主要对哺乳动物β-防御素在哺乳动物雌性生殖系统组织中的分布、作用及其调控进行了综述,并对其应用前景进行了展望,以期更好地揭示β-防御素在雌性生殖系统中的影响,从而为β-防御素的进一步研究提供理论依据。 相似文献
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Exogenous pituitary and recombinant growth hormones induce insulin and insulin-like growth factor 1 resistance in pig adipose tissue 总被引:1,自引:0,他引:1
In the present study, pigs were treated daily for 7 days with exogenous porcine growth hormone (pGH; 70 micrograms/kg BW) in order to determine whether pGH induced insulin and insulin-like growth factor 1 (1GF-1) resistance in pig adipose tissue. In the first experiment, pituitary-derived pGH (ppGH) decreased basal and insulin-stimulated lipogenesis by 50%. Insulin sensitivity decreased more than 90% as the result of pGH treatment. Sensitivity and responsiveness to IGF-1 were decreased 50% by ppGH. In a second experiment, pigs were treated daily (70 micrograms/kg BW) with exogenous pituitary pGH (ppGH) or recombinant pGH (rpGH) for 7 days in order to determine if the effects of pGH were intrinsic properties of the hormone. Both rpGH and ppGH caused similar decreases in basal rates of lipogenesis, insulin- and IGF-1-stimulated lipogenesis, and insulin and IGF-1 responsiveness in pig adipose tissue. In summary, the decrease in adipose tissue growth of pigs treated chronically with pGH is due in large part to the suppression of fatty acid synthesis and a decrease in the ability of insulin to stimulate lipid synthesis in pig adipocytes. These responses are intrinsic properties of pGH since the effects of rpGH mimicked those of ppGH. The role and importance of a decrease in IGF-1 responsiveness remains to be resolved. 相似文献
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为确诊贵州省都匀市某养殖场的猪死亡病因,采集病死猪病料进行猪繁殖与呼吸综合征病毒、猪瘟病毒、猪伪狂犬病病毒、猪圆环病毒2型核酸检测,细菌分离鉴定及药物敏感试验。结果:猪繁殖与呼吸综合征病毒实时荧光定量RT-PCR检测和猪圆环病毒2型PCR检测核酸均为阳性,其余病毒核酸检测均为阴性。细菌分离培养表明存在细菌感染,分子生物学鉴定为奇异变形杆菌;分离菌对硫酸安普霉素、硫酸粘菌素、盐酸大观霉素+盐酸林可霉素、氟苯尼考较敏感,对多种药物产生耐药。结论:确诊病例为猪繁殖与呼吸综合征病毒、猪圆环病毒2型、奇异变形杆菌混合感染。 相似文献
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为了解贵州省猪源沙门氏菌对β-内酰胺类抗菌药物耐药性及其耐药基因的流行情况,本试验从贵州省9个地区规模养猪场中分离鉴定130株沙门氏菌,采用微量肉汤稀释法测定其对常用的8种β-内酰胺类抗菌药物的敏感性,并用PCR法对β-内酰胺酶耐药基因进行检测。结果显示,沙门氏菌对常用的β-内酰胺类抗菌药物耐药性十分严重,其中对头孢他啶的耐药率为100%,其次是氨苄西林和阿莫西林,耐药率分别为80.77%和76.15%,耐药率最低的是头孢噻呋和头孢氨苄,均为46.15%。所有菌株均为多重耐药,其中最少为二重,占总数的2.31%,最多为八重,占总数的4.62%,多重耐药主要集中在四至七重,占总数的88.46%。PCR结果显示,SHV耐药基因未检出,TEM、OXA、CTX-M 3种基因检出率分别是85%、75%和46%,细菌的耐药性与相关耐药基因的检出率基本呈正相关。结果表明,猪源沙门氏菌对β-内酰胺类药物具有普遍耐药性,其中头孢他啶尤为严重。TEM、OXA、CTX-M基因是贵州省猪源沙门氏菌主要耐药基因,临床日益严重的耐药现象与耐药基因的普遍存在有很大的关系。 相似文献
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本试验旨在克隆、鉴定猪硒蛋白P基因(Sepp1),并探明其在猪不同组织中的mRNA相对表达量,为以猪为模型研究硒蛋白P(Sel P)的功能奠定基础。根据表达序列标签(EST)序列设计引物,利用c DNA末端快速克隆(3'-RACE)技术从猪肝脏总RNA中扩增出含开放阅读框(ORF)至poly A片段,然后与EST序列进行拼接;采用荧光定量PCR技术考察Sepp1在猪9个组织中的mRNA相对表达量。结果显示:1)扩增出共1 707 bp的片段,测序后与EST拼接获得了2 109 bp的猪Sepp1序列,并提交至NCBI Gen Bank数据库,序列号为EF113596.2;该基因1 170 bp的ORF编码区和对应的氨基酸残基与人相应序列分别有83.72%和75.64%序列同源性,其编码390个氨基酸,含有14个硒代半胱氨酸(Sec)残基,分别位于第59、267、286、309、311、327、339、352、354、361、376、378、385和387位。2)Sepp1 mRNA在猪组织中广泛分布,在肝脏中具有最高分布,依次为甲状腺肾脏睾丸下丘脑脾脏垂体心脏肌肉。本试验成功克隆、鉴定了猪Sepp1,检测了其在猪不同组织中表达分布情况,为其进一步以猪为模型探讨其功能奠定了基础。 相似文献
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抗菌肽可抵御细菌、病毒和真菌的入侵,在人类和家畜的先天性防御系统中具有重要的作用,是有望用于预防和治疗的药物,因此,抗菌肽被称为"新一代的抗生素"。抗菌肽是一个阳离子肽,其中的一个大家族就是防御素。防御素的结构中普通带有一个β-片状结构,其中包含3个分子内二硫键,可分为α-防御素、β-防御素和θ-防御素,其中β-防御素是最大的一个家族,在人类和家畜的组织内均有表达。结合已有的研究成果,作者主要对家畜体内防御素的表达、多态性及其作为健康和生产性能的遗传标记的潜在应用作一综述。 相似文献
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Campylobacter coli is a food-borne zoonotic pathogen causing human gastroenteritis worldwide. The organism is a commensal in the intestine of many food production animals including fattening pigs. The role of the pig as a potential reservoir for C. coli affecting human either directly or via poultry has hardly been investigated and genetic characterization of porcine strains is needed to address this question. For this aim multilocus sequence typing (MLST) and flaB typing was applied to 256 C. coli isolates from faeces of fattening pig collected during 2009 at different slaughterhouses in Switzerland. In addition genotypic resistances towards macrolides and quinolones based on point mutations in the 23S rRNA and gyrA genes, respectively, were determined. Of the 67 sequence types (STs) obtained by MLST, 37 were found for the first time. flaB typing revealed 46 different types with 14 of them being novel and was useful to further differentiate strains with an identical ST. Quinolone resistance was detected in 33.6% and macrolide resistance was found in 10.6% of isolates. Comparison with 99 C. coli pig isolates from 2001 revealed a significant decrease in antibiotic resistance towards both groups of antibiotics and there was high overlap between genotypes of 2001 and 2009. Little overlap of porcine genotypes was found with 97 C. coli isolates from poultry collected 2008, however, macrolide resistance was significantly higher in pig isolates. In conclusion, C. coli from Swiss pig are heterogeneous containing many novel STs, findings that could reflect the partitioned Swiss pig production with almost no international breed exchange. The antibiotic resistance echoes the use of corresponding drugs in the Swiss livestock production and indicates the efficacy of restrictive application of antibiotics in order to reduce resistances. 相似文献