鸡白痢沙门菌研究进展

鸡白痢沙门菌是鸡白痢的病原,具有高度适应专一宿主的特点。它可引起雏鸡的急性全身性感染,发病率和病死率极高;成年鸡被感染后可引起体质量下降、产蛋率和孵化率降低、组织病变、白痢和生殖道畸形等,给很多国家的养鸡业带来巨大危害,并引起严重的经济损失。为了更好的预防和控制、甚至最终净化该病,需要对鸡白痢沙门菌进行深入的研究。本文从病原学及其基因组特征、流行病学、致病性及毒力基因、检测方法和防控措施等方面介绍了鸡白痢沙门菌的研究进展,并对其研究趋势进行了展望。     

肠炎沙门菌感染鸡lncRNA表达谱分析

研究旨在分析鸡感染肠炎沙门菌后长链非编码RNA(lncRNA)的表达谱,了解lncRNA在肠炎沙门菌感染过程中发挥的作用.通过提取脾脏组织总RNA进行高通量测序,利用生物信息学方法进行比较分析.根据差异显著的lncRNAs与mRNAs之间的位置关系预测lncRNAs顺式调控的邻近基因,并对邻近基因进行GO富集和KEGG...     

鸡白痢沙门菌和鸡伤寒沙门菌PCR-RFLP鉴别

根据鸡白痢沙门菌和鸡伤寒沙门菌flic基因可变区两端的保守序列设计1对引物,PCR扩增出约866 bp的产物,用HinplI对PCR产物进行酶切,经RFLP分析区分鸡白痢沙门菌和鸡伤寒沙门菌.利用该技术对1株鸡白痢沙门菌标准株及2株鸡伤寒沙门菌标准株进行分子鉴别,结果与预计的RFLP模式相符,证明该方法可行.在此基础上...     

鸡白痢沙门菌研究进展

本文就鸡白痢沙门菌的基因组学、与鸡伤寒沙门菌的鉴别方法、感染与致病机制、防治措施等方面的研究进展进行总结,以期为相关研究提供参考。     

鸡白痢沙门菌外膜蛋白C的原核表达与免疫反应性分析

利用PCR方法扩增鸡白痢沙门菌主要抗原外膜蛋白C的基因,将其定向克隆至pET30a(+)原核表达载体,转化大肠杆菌BL21表达菌,利用His标签的蛋白纯化柱纯化重组蛋白,通过免疫印迹检测重组蛋白活性。通过BamHⅠ/HindⅢ双酶切鉴定获得了pET30a-C原核表达重组质粒,转化BL21表达菌后,通过IPTG诱导获得以包涵体形式存在的重组蛋白,重组蛋白纯化后免疫印迹检测显示具有良好的反应原性。本研究为鸡白痢基因工程抗原的制备及诊断试剂研究奠定了基础。     

鸡白痢沙门氏杆菌感染雏鸡后SOD及GSHPx活性的变化

2日龄雏鸡被鸡白痢沙门氏杆菌人工感染后，分别剖取其法氏囊，脾脏，心脏，肝脏和肾脏并测定其中超氧化物歧化酶（SOD）及谷胱甘肽过氧化的酶（GSHPx)的活性。结果表明：攻毒组与对照组相比，SOD活性除心脏外，其余被测器官均呈显下降；GSHPx活性在各被测器官中均呈显下降。     

鸡白痢沙门菌基因组差异片段的筛选与分析

采用抑制性消减杂交技术（SSH）对鸡白痢沙门菌C79-13株与鸡伤寒沙门菌Sg9株进行了基因组差异片段分析.结果,从C79-13株中共检出13个特异性差异片段.经同源分析,这些序列可分为3类：噬菌体相关序列、质粒相关序列和已知功能序列.这些差异片段包含一些重要的沙门菌毒力相关基因,如编码大肠杆菌素、IpaJ蛋白、尾突蛋白、切除酶的基因.结果表明,鸡白痢沙门菌C79-13株与鸡伤寒沙门茵Sg9株基因组问存在较多差异基因,这些差异片段为确定鸡白痢沙门菌特异性遗传标志,建立分子鉴别新体系提供了基础.     

肉鸡鸡白痢沙门菌的分离鉴定

2009年5月,北京郊区某肉鸡养殖户的2 000只7日龄雏鸡出现拉白色稀粪,肝脏有黄色结节等症状和病变的疾病。为探索该病病因及制定有效防治措施,对病鸡样品进行了细菌学检验。通过细菌分离、生化试验、PCR及16 S rRNA基因测序鉴定出1株鸡白痢沙门菌。该分离株感染试验鸡能复制出与其临床表现一致的病例并能引起死亡。表明鸡白痢沙门菌是危害北京郊区该养殖户肉鸡的病原。     

河北省保定地区雏鸡鸡白痢沙门菌的分离鉴定及耐药性检测

为了有效防控雏鸡白痢沙门菌病,试验自保定某蛋种鸡场疑似为鸡沙门菌病雏鸡采取肝脏病料进行细菌的分离培养、生化鉴定、鸡白痢沙门菌多价血清学鉴定及沙门菌inv A基因PCR鉴定,并对分离菌进行致病性检测及对7种抗菌药物的耐药性检测。结果表明,10株分离菌的形态特征、生化特性、血清学鉴定结果符合鸡白痢沙门菌的特征,说明从病死雏鸡组织中分离出的细菌为鸡白痢沙门菌。沙门菌inv A基因PCR扩增出373 bp目的片段,进一步证实分离菌为鸡沙门菌。用分离菌株接种雏鸡,其死亡率高达90%,表明该菌株有很高的致病性。10株分离菌株对阿莫西林和青霉素耐药率达100%,对阿齐霉素的耐药率达90%,而对阿米卡星、头孢唑林和庆大霉素耐药性较弱、对氧氟沙星较为敏感。3耐菌株多重耐药比例为42.86%,4耐菌株多重耐药比例为57.14%,5耐菌株多重耐药比例为71.43%,说明雏鸡沙门菌分离株对所试抗菌药物均表现出不同程度的耐药性,且表现出多重耐药现象。本试验为鸡白痢沙门菌病的防治提供参考。     

白痢沙门菌CpxR的生物信息学分析和原核表达

对白痢沙门菌二元调控系统响应蛋白CpxR进行生物信息学分析,提示CpxR可能发挥了重要的生理功能。同时,构建了重组表达载体pET32a-CpxR,转化表达菌株BL21后,对其进行诱导表达,SDS-PAGE和Western blot结果表明CpxR获得了正确表达。纯化蛋白免疫小鼠制备了多抗血清,Western blot验证其有一定的免疫原性。为深入研究其生理功能和调控机制奠定了理论基础。     

CpxR对鼠伤寒沙门菌的黏菌素耐药相关基因pmrB和phoQ调控作用的研究

为了探索 cpxR 对鼠伤寒沙门菌的黏菌素耐药相关基因 pmrB 和 phoQ 的调控作用,用overlapping PCR扩增得到 cpxR 、 pmrB 和 cpxR 、 phoQ 共表达基因 cpxR - pmrB 、 cpxR - phoQ ,用2倍微量肉汤稀释法对构建的 pmrB 、 phoQ 单基因过表达菌株JSΔ acrB Δ cpxR :: kan /p pmrB (JSΔΔ/p B )、JSΔ acrB Δ cpxR :: kan /p phoQ (JSΔΔ/p Q )和 cpxR - pmrB 、 cpxR - phoQ 共表达菌株JSΔ acrB Δ cpxR :: kan /p cpxR - pmrB (JSΔΔ/p RB )、JSΔ acrB Δ cpxR :: kan /p cpxR - phoQ (JSΔΔ/p RQ )进行黏菌素最小抑菌浓度(MICs)的测定,同时以各菌株在LB中的OD 600 nm 值绘制生长曲线,以各菌株在不同浓度的黏菌素中的存活率绘制杀菌曲线。结果:成功构建的鼠伤寒沙门菌 pmrB 、 phoQ 的单基因过表达菌株JSΔΔ/p B 、JSΔΔ/p Q 和 cpxR - pmrB 、 cpxR - phoQ 共表达菌株JSΔΔ/p RB 、JSΔΔ/p RQ 的MIC结果显示,JSΔ acrB Δ cpxR :: kan /p cpxR (JSΔΔ/p R )的MIC值较JS下降93.75%,与本实验室前期研究结果一致。JSΔΔ/p B 、JSΔΔ/p Q 的MIC值较JS均上升3倍,而JSΔΔ/p RB 、JSΔΔ/p RQ 的MIC值较JS分别降低50%和75%。生长曲线结果显示JSΔΔ/p R 的生长活性最低,JSΔΔ/p B 、JSΔΔ/p Q 、JSΔΔ/p RB 和JSΔΔ/p RQ 的生长活性均低于JSΔ acrB Δ cpxR :: kan /pHisA(JSΔΔ/pHisA)。黏菌素的杀菌曲线结果显示JSΔΔ/p B 和JSΔΔ/p Q 在不同浓度的黏菌素中的存活率显著高于黏菌素较敏感的JSΔΔ/p RB 和JSΔΔ/p RQ 。上述结果表明:CpxR能够通过PmrB和PhoQ调控鼠伤寒沙门菌对黏菌素的敏感性。     

食蟹猴骨髓采集穿刺方法及其骨髓象测定

为探索采集食蟹猴骨髓的操作方法及其正常骨髓象指标，试验采集了60只食蟹猴的髂骨骨髓，并测定其骨髓象、测得的骨髓象及采集过程中的注意事项。结果表明，可以顺利的采出骨髓，雌雄之间晚幼红细胞、粒红比有显著性差异（P〈O．05），其余无显著差异。     

Detection and Molecular Characterization of Salmonella enterica Serovar Eppendorf Circulating in Chicken Farms in Tunisia

Salmonella enterica subsp. enterica serovar Eppendorf, with antigenic formula 1,4,12,[27]:d:1,5, is an infrequent serovar. However, 14% (20 of 142) of the isolates recovered during June–July 2012 in chicken farms in Tunisia belonged to S. Eppendorf. These isolates were analysed for resistance and virulence profiles. None of them were susceptible to all antimicrobials tested, while 70%, 60%, 50%, 50%, 20% and 5% were resistant to sulphonamides (sul1, sul2 and sul3), streptomycin (aadA1‐like), trimethoprim (dfrA1‐like), nalidixic acid (GyrA Asp₈₇→Asn and not identified), gentamicin (not identified) and ampicillin (bla_TEM‐1‐like). About 30% of the isolates showed decreased susceptibility to ciprofloxacin and carried the qnrB gene; 65% of the isolates were multidrug resistant and contained class 1 integrons with sul1 or sul3 in the 3′ conserved segment. The orgA, ssaQ, mgtC, siiD and sopB virulence genes located on SPI1 to SPI5 and the fimbrial bcfC gene were present in all isolates; the sopE1 and sodC1 carried by prophages were variably detected; however, the prophage gipA gene and the spvC gene of serovar‐specific virulence plasmids were absent. Altogether, ten resistance and three virulence profiles were identified. Typing of the isolates with XbaI‐ and BlnI‐PFGE supports a close relationship, although they appear to be evolving under selective pressure probably caused by antimicrobial use in chicken husbandry. As far as we know, this is the first study investigating the molecular bases of antimicrobial drug resistance, the virulence gene content and the PFGE profiles of S. Eppendorf. The epidemiological surveillance of this serovar would be necessary to evaluate its possible impact on human health, particularly in Tunisia and other African countries where it was already reported.     

食蟹猴骨髓采集穿刺方法及其骨髓象测定

为探索采集食蟹猴骨髓的操作方法及其正常骨髓象指标,试验采集了60只食蟹猴的髂骨骨髓,并测定其骨髓象、测得的骨髓象及采集过程中的注意事项.结果表明,可以顺利的采出骨髓,雌雄之间晚幼红细胞、粒红比有显著性差异(P＜0.05),其余无显著差异.     

Profiles of Fatty Acids in Different Bone Structures of Growing Chicks

This study was concerned with the dynamics of fatty acids in tissues involved in the growth and mineralization of the femur of Starbro chicks from 1 to 50 days of age. Four chickens that died of suffocation were obtained each day. Altogether, 400 femoral bones were studied in five age groups (I–V). Compact bone, spongy bone and articular cartilage were sampled. Lipids were extracted according to Folch and fatty acids were separated using gas chromatography. The fatty acid profile was found to change with age. Fatty acids with the highest content in bone were C_18:1, C_16:0, C_18:2 and C_18:0. The highest content of fatty acids was found in spongy bone and the lowest in articular cartilage. Several correlations were revealed between individual fatty acids. The following conclusions were drawn. (1) Fatty acid profiles in compact bone, spongy bone and articular cartilage change with age of chicks. (2) Oleic (C_18:1), palmitic (C_16:0), linoleic (C_18:2), stearic (C_18:0) and arachidonic (C_20:4) acids accounted for most of the fatty acid pool. (3) Correlations in the content of fatty acids were noted between bone structures.     

Clonal relatedness of Salmonella isolates associated with invasive infections in captive and wild-caught rattlesnakes

This study examines the serotype distribution and clonal relatedness among Salmonella isolates obtained from healthy and diseased snakes. Isolates from extraintestinal body sites were obtained through routine diagnostic lab submissions from snakes in two facilities that had experienced a high prevalence of osteomyelitis in Crotalus species. Gastrointestinal isolates were predominantly from fecal samples collected from healthy snakes of both crotalid and non-crotalid species in one facility. PFGE macrorestriction analysis of Salmonella isolates confirmed the clonal and species-restricted nature of Salmonella serotype IIIa 56: z4, z23: - in one facility. Fourteen of 15 isolates from suspected osteomyelitis lesions in wild-caught snakes at the second facility were also from Salmonella subgroup IIIa (serotype IIIa 18: z4, z23: -) and appeared to be closely related by PFGE. Evaluation of a PCR assay for the spvC gene in 209 isolates demonstrated that this method consistently distinguished isolates of subgroup IIIa from those of subgroup IIIb. The data presented establish that Salmonella of subgroup IIIb are abundant and regularly associated with gastrointestinal shedding in snakes but that Salmonella in subgroup IIIa disproportionately cause infections in bone or other extraintestinal sites.     

不同光照下褪黑素变化对鸡骨髓内c-fos原癌基因表达的影响

为了找出褪黑素分泌变化与c-fos原癌基因表达之间的关系,本研究控制不同光照时间饲养1日龄雏鸡50只,取骨髓组织,经免疫组化试验,结果显示：①单核细胞系胞浆出现阳性信号;巨核细胞系、粒细胞系和淋巴细胞系胞核出现阳性信号;红细胞系无阳性信号;②随着光照时间的延长,c-fos原癌基因的表达量呈增长趋势。结果表明,c-fos与骨髓细胞的细胞增殖和分化相关。褪黑素的增高能够显著抑制c-fos原癌基因的表达,且褪黑素的减少能够刺激c-fos的表达。     

1例鸡白痢沙门氏菌的分离鉴定与耐药性分析

为查明河南省新乡市某规模化蛋鸡场疑似沙门氏菌感染病例的病原，进而制定合理的治疗方案，本研究无菌采集疑似病雏鸡肠管样品，用革兰氏染色、培养特性观察、生化试验、PCR方法对其进行确诊，并进行病原回归试验，采用药敏纸片琼脂扩散法（K-B法）分析分离菌对19种常见抗生素的耐药性。结果显示，本试验成功分离了一株革兰氏阴性短杆菌，该分离菌符合鸡白痢沙门氏菌的培养特性和生化特性；PCR成功扩出invA基因，通过与GenBank数据库比对分析确定该细菌为鸡白痢沙门氏菌；用分离细菌株感染SPF鸡能复制出与自然感染一致的病例，说明鸡白痢沙门氏菌是造成本养鸡场雏鸡发病的主要病原；分离株具有较强的致病性和多重耐药性，对阿米卡星、苯唑青霉素、青霉素耐药，对复达欣、氨苄青霉素、头孢曲松等药物敏感，将敏感抗生素用于临床治疗效果明显。结合以上结果，本研究提出该病的具体防治措施，并取得了较好的效果，为鸡白痢沙门氏菌的分离鉴定及防治提供了参考，对鸡白痢沙门氏菌病病原的早期诊断和治疗具有重要临床意义。     

鸭肠炎病毒感染鸭肝脏组织miRNA表达谱差异分析

为探究鸭感染鸭肠炎病毒（Duck enteritis virus,DEV）后肝脏miRNA表达谱的差异,试验以DEV-GZ株经腿部肌肉接种30日龄麻鸭,于感染后66、90和114 h采集鸭肝脏组织样本,提取组织总RNA,经质检合格后,采用高通量测序技术对对照组和试验组样品进行miRNA测序,筛选出DEV感染鸭肝脏组织的差异表达miRNA,对其进行生物信息学GO功能分类和KEGG信号通路分析,并随机选取部分差异表达miRNA进行实时荧光定量PCR验证。结果显示,鸭感染DEV后66、90和114 h,肝脏组织差异表达miRNAs数量分别为227、225和231个。GO功能注释显示,感染鸭肝脏差异表达miRNA在生物过程分类中主要为细胞过程、单有机体过程和代谢过程类别;在细胞成分分类中主要是细胞、细胞部分和细胞器类别;在分子功能分类中主要是绑定分子功能和催化活性功能类别。KEGG通路富集显示,差异表达miRNA主要涉及PI3K-Akt、JAK-STAT、磷脂酰肌醇信号通路系统、ECM-受体相互作用、MAPK、Wnt、Toll样受体、IL-17、脂质代谢、钙离子信号通路和cAMP等信号通路,其中感染66 h差异表达miRNA主要在生物系统及神经系统中发挥作用;感染90 h主要在内分泌系统及消化系统中发挥作用;感染114 h主要在全身生物、免疫和消化系统等中发挥作用。选取10个差异表达miRNAs进行实时荧光定量PCR验证,结果与高通量测序结果一致。表明DEV感染对鸭肝脏组织miRNA表达具有显著影响,为从宿主miRNA角度揭示DEV致病机制提供了参考依据。     

92匹马骨髓细胞正常值的测定

通过对92匹三河马（其中成年马67匹，育成马25匹）骨髓内各种细胞的形态学观察，计算出成年马和育成马骨髓细胞的正常值，为马血液疾病的诊断提供了参考依据。