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1.
为了解浙江省H9N2亚型禽流感病毒(AIV)血凝素(HA)和神经氨酸酶(NA)基因的分子特征和遗传变异情况，本试验对2012—2021年分离到的14株H9N2亚型AIV分离株进行HA和NA基因序列测定和分析。结果显示：14株分离株的HA和NA基因均属于Y280分支，HA核苷酸同源性为91.5%～99.4%,NA核苷酸同源性为89.0%～98.7%,其与疫苗株CK/SS/94、CK/F/98、CK/6/96和CK/1/00的HA核苷酸同源性为86.0%～91.1%。14株分离株HA蛋白裂解位点氨基酸组成均为RSSR↓GLF;受体结合位点主要表现为K141N、A142T、T155N、H183N和V190T突变，其中第226位和第228位全部为L和G,可与α-2,6唾液酸受体结合，具有感染人的特性；蛋白潜在糖基化位点均为6个，主要变异表现在第200～202位1个位点缺失和第295～297位1个位点增加；抗原相关位点主要表现为G82E、S137D、D145G、N159G、A160D、T192R和N193D突变，此外，有5株出现D160N突变。14株分离株NA蛋白存在6个潜在糖基化位点，其中1株... 相似文献
2.
猪圆环病毒2型江苏分离株的遗传进化分析 总被引：1，自引：0，他引：1
采用PCR方法扩增了15个猪圆环病毒2型（PCV 2）江苏分离株的基因组DNA,以这些毒株的ORF2核苷酸序列进行遗传进化分析。经序列比较发现,所有分离株均属于2b基因群,其中7株为1A/1B亚群、8株为1C亚群;毒株间核苷酸同源性为93.6%~100%,所编码的Cap蛋白氨基酸同源性为92.3%~100%。PCV 2江苏分离株Cap蛋白的主要变异区域为53~90、121~151和190~210位氨基酸;R59、R89、S90、S121、T134、S169、A190、E210为1A/1B亚群分离株的特征氨基酸,而F8、I53、N68、L89、T90、T121、N134、R169、D210、I215、K234则是1C亚群分离株的特征氨基酸。 相似文献
3.
为了解国内鸡群马立克病毒(MDV)流行毒株的分子特征,采用细胞培养法对马立克病疑似病鸡抗凝血进行MDV分离,间接荧光法鉴定MDV血清型,PCR扩增分离病毒的meq和pp38两个主要致病基因,所得序列与MDV参考毒株的序列进行比对分析。结果显示,共分离鉴定出2株MDV I型毒株,分别命名为JS0316和JS0424。meq基因编码的氨基酸序列结果显示,2个MDV分离株缺乏弱毒疫苗株的特征(A71S、P194-),具有MDV强毒分离株的分子特征(D80Y、V115A、T139A、P176R和P217A)。同时,JS0316 Meq蛋白出现Q93R和V123A突变,pp38蛋白出现L98I和F240S突变,而JS0424 Meq蛋白出现P217T突变,pp38蛋白出现W67G和V210A突变。因此,2株MDV均具有国内流行强毒株的分子特征,同时存在新的基因突变。 相似文献
4.
本研究将禽呼肠孤病毒广西两分离株R1、R2和美国分离株Iso1 S1基因中编码σ3蛋白的基因片段进行克隆和鉴定.对克隆片段测序后与参考株S1133、1733、138、176毒株的S1基因相应序列进行比较分析.结果表明,广西分离株R1、R2与美国分离株Iso1以及S1133、1733、176毒株的核苷酸和推导氨基酸的同源性均在95%以上,上参考株138的同源性在81%～85%之间.由此可见,除了与138参考株外,广西分离株R1、R2和美国分离株Iso1与其他比较的毒株的S1基因上存在很大的相关性. 相似文献
5.
我国部分地区鸡新城疫病毒流行株遗传变异分析 总被引：3，自引：2，他引：1
将近年来从不同地区临床病例中分离鉴定的10株鸡新城疫病毒(NDV)流行株,用RT-PCR方法分别扩增出大小为535 bp的F基因重要功能区,并克隆到pGEM-T载体上,经酶切分析结合核苷酸序列测定而确诊。10株分离株核苷酸序列同源性达到81.9%～99.4%,其中8个分离株F蛋白裂解位点的氨基酸顺序为:112R-R-Q/R-K/R/R/F117,为NDV强毒株,且具有基因Ⅶ型的典型特征,即在101位和121位氨基酸残基分别为K(赖氨酸)和V(缬氨酸);其余2株病毒F蛋白裂解位点的氨基酸顺序为:112G-R-Q-G-R-L117,表明它们为NDV弱毒株,在13位和17位氨基酸分别为M(蛋氨酸)和I(异亮氨酸),属于基因Ⅱ型。根据上述测序结果并参照已发表NDV F基因序列绘制出遗传进化树,遗传进化树显示,上述8个强毒株和台湾95年分离株同源性较高,而2个弱毒株与La Sota株同源性较高。 相似文献
6.
《中国兽医学报》2019,(8):1513-1525
H9N2禽流感病毒自1994年在广东首次报道暴发以来,已在国内广泛地流行,给养禽业带来了极大的损失,甚至威胁着人类的健康。为了解2017年国内H9N2亚型禽流感病毒的遗传进化和分子特征变化,本研究从江苏、安徽、山东等地区的大型鸡场中分离到了10株H9N2亚型禽流感病毒。对10株分离株的基因分析表明,所有分离株均属于在2013年后占主导地位的G57型,由BJ/94系的HA、NA和NS基因,DK1系的PB2基因,F/98系的PB1,PA和NP基因以及G1/97系的M基因的四重组病毒组成,并且分离株的EID_(50)显著低于早期分离的H9N2禽流感病毒。10株分离株中有7株受体结合位点的198位发生了A到T,或者A到V的替换,并发生糖基化位点在218位的缺失,313位的增加。与近5年已经发表的流行株HA蛋白比较,所有分离株的抗原位点均发生了S127R、S183N、D216E、T220I、Q235M、S283R突变,NA基因在61～63位缺失NIT;表明分离株的抗原发生了变异。而分离株内部基因PB2上的K318R突变,PB1上的L13P突变,PA上的K356R突变、Q/T/S400P突变,NS上的E227K突变,NP上的D34S、K398Q突变,M1上的V15I突变以及M2上的I28V、L55F突变,使分离株更易感染哺乳动物,说明必需要继续加强H9N2禽流感病毒的监测,密切关注其对人类可能造成的影响。特别是10株分离株中首次出现的NA基因的E433D突变和PB2基因的E627V突变是否会给H9N2禽流感病毒增加新的生物学特性还有待进一步研究。 相似文献
7.
免疫鸡群新城疫病毒的分离与分子鉴定 总被引：3，自引：1，他引：3
从免疫鸡群中分离到9株新城疫病毒（NDV），其中5株为强毒株，4株为中强毒株。用RT—PCR扩增F基因cDNA片段，并将其分别克隆到pGEM—Teasy载体中。序列分析结果表明，上述分离株F基因长度为1662bp，编码553个氨基酸，其F蛋白的氨基酸序列同源性为96．0％～99．8％；但与常见疫苗株的氨基酸同源性仅为87.6％～92.2％，F蛋白裂解位点序列为^112R-R-Q／R—K—R—FI—G^119,均属于基因Ⅶ型NDV。 相似文献
8.
用SDS—PAGE分析鸡毒霉形体广西分离株的结构蛋白 总被引：6，自引：1，他引：5
应用SDS－PAGE对鸡毒霉形体（Mycoplasma gallisepticum,MG)4个标准株和5个广西分离株的结构蛋白进行了比较分析。结果，在凝胶电泳图谱中10－100ku蛋白分子质量之间，F株缺少87ku蛋白带，Y3株在最靠近87ku蛋白带的上方和下方各缺少1条蛋白带，H2株和Y2株缺少64ku蛋白带，CH株缺少29ku蛋白带，97、75、43ku处的蛋白带为4个MG标准株和5个MG分离株所共有。表明9个MG供试菌株的结构蛋白都存在一定的差异，广西MG分离株的结构蛋白呈现多样性。 相似文献
9.
新城疫病毒广西分离株F基因的克隆和序列分析 总被引：4，自引：1，他引：4
根据GenBank中登录的新城疫病毒(NDV)F基因序列设计了2对引物，对从广西分离的10株NDV毒株的F基因进行了分段扩增和序列测定，其基因序列全长均为1662bp，编码553个氨基酸，均有6个潜在的糖基化位点。将其F基因的核苷酸序列及推导的氨基酸序列与已发表的10株NDV参考株的F基因序列进行了比较。结果表明，核苷酸序列的同源性为82．6％～98．1％，氨基酸的同源性为87．7％～98．7％。这10株NDV广西分离株在裂解位点的氨基酸序列(^112R—R—Q—K／R—R—F^117)与NDV强毒株特征相符合。系统发育树、酶切位点分析和基因分型结果表明，10株NDV广西分离株中GX1／00、GX2／00、GX4／00、GX6／02、GX7／02、GX9／03、GX10／03和GX11／03为基因Ⅶd亚型，GX3／00和GX5／00为基因Ⅲ型。 相似文献
10.
《云南畜牧兽医》2020,(3)
建立西藏环状病毒(Tibet orbivirus, TIBOV)RT-PCR诊断方法。根据云南省新分离到的TIBOV Seg-7片段序列设计1套巢式引物为120S7F1/R1、120S7F2/R2。以TIBOV DH13C120株病毒核酸为模板,优化反应条件,建立巢式RT-PCR检测方法,并对云南省新分离的9株TIBOV进行核酸检测。分别采用外引物(120S7F1/R1)和内引物(120S7F2/R2)对TIBOV DH13C120株进行RT-PCR扩增,退火温度分别为52℃和54℃,外引物扩增出片段大小为1 050 bp条带;内引物扩增出的片段大小为500bp,扩增条带大小与设计预期相一致。而蓝舌病毒(BTV)JCC12-7株和阴性对照两轮扩增均为阴性,采用该方法对云南省新分离的9株TIBOV、2株BTV和1株鹿流行性出血热病毒(EHDV)进行检测,9株TIBOV扩增均为阳性,而BTV、EHDV和阴性对照均为阴性。建立了TIBOV巢式RT-PCR检测方法,该方法可用于云南省目前动物或媒介中流行的TIBOV核酸检测。 相似文献
11.
中国猪瘟兔化弱毒株（C-株）兔脾组织毒主要保护性抗原E2（gp55）基因序列分析 总被引：7，自引：2，他引：5
利用反转录（RT）及套式PCR（N-PCR）方法扩增了中国猪瘟兔化弱毒株（C-株）兔脾组织毒主要保护性抗原E2（gp55）基因，成功地将其克隆并测定了核苷酸序列，与国内外已发表的猪瘟病毒（HCV）E2基因序列比较的结果是C-株兔脾毒与C-株细胞（SK6）毒、C-株疫苗（犊牛睾丸细胞，HCLV-C）毒、HCV-SM株（石门）毒、Brescia株（荷兰）毒、Alfort株（德国）毒的E2核苷酸序列同源性分别为98.87％、98.34％、94.58％、91.00％、80.78％；氨基酸同源性分别为98.95％、97.37％、94.22％、91.60％、89.23％。对C-株兔脾毒与C-株细胞毒、经典强毒及国内流行野毒E2上的A、B、C三个中和性抗原区的氨基酸组成进行了比较，其结果为C-株兔脾毒与C-株细胞毒的差异很小甚至没有差异，而与流行野毒及经典强毒在B、C区有较大的差异。我国经典强毒石门毒与国内80年代和90年代流行毒之间有明显的差异，表明我国猪瘟流行毒株发生了变化。 相似文献
12.
9株鸡毒支原体29 Ku多肽基因的克隆与序列分析 总被引：4，自引：0，他引：4
根据已发表的鸡毒支原体(MG)S6株29Ku多肽基因序列设计了1对引物,以9株(广西分离株5株、标准株4株)DNA为模板进行PCR扩增,均得到802bp的特异性片段,将9株MG PCR产物纯化后克隆到pMD18-T载体上,得到重组质粒.重组质粒经PCR法和EcorⅠ、SalⅠ双酶切等方法鉴定后,测定了9株29 Ku多肽基因序列,并在基因库中S6标准株的29 Ku多肽基因序列进行分析比较.结果表明,5株分离株与5株标准株29Ku多肽基因核苷酸序列同源性分别为94.4%～99.9%,推导的氨基酸同源性分别为89.7%～99.2%.从各毒株的进化分析表明,5个分离株与标准强毒株S6、A5969、K1501和PG31强毒株间遗传距离较近,而5个分离株与标准株F疫苗株间遗传距离则较远. 相似文献
13.
Mycoplasma gallisepticum (MG) is an important avian pathogen causing significant economic losses within the poultry industry. In an effort to develop tools to aid in MG research and diagnostics, we have compared sequences of the attenuated MG vaccine strain ts-11 to those of commonly used pathogenic challenge strains in search of a simple means of differentiation. Via gapA sequence alignments and comparisons, we have identified and designed primers facilitating strain differentiation. When applied to conventional polymerase chain reaction (PCR) assay at low annealing temperature, the primer sets allow for the differentiation of MG attenuated vaccine strains ts-11 as well as the attenuated MG vaccine strain 6/85 from the commonly utilized MG challenge strains R(low), R, and S6. Conventional PCR differentiation is based on the visualization of sole products with the attenuated MG strains ts-11 and 6/85 and the lack of the corresponding products from MG strains R(low), R, and S6. When applied to MG strain F, product visualization varies with the applied primer set. The differentiation of MG strains ts-11 and 6/85 from the pathogenic challenge strains was also accomplished via real-time analyses, however, the primer sets were not able to differentiate MG strains ts-11 and 6/85 from selected MG field isolates. 相似文献
14.
Two new monoclonal antibodies (MAbs), D6D8D5 and B3E6F9, both directed against Haemophilus paragallinarum serovar C hemagglutinating (HA) antigen, were produced, and characteristics of the MAbs were compared with those of the previously described MAb F2E6 in dot-blot and hemagglutination-inhibition (HI) tests using two representative H. paragallinarum strains each of serovars A, B, and C strains and 55 Japanese serovar C field isolates. MAb D6D8D5 and MAb F2E6 reacted with all serovar C strains and field isolates in the dot-blot test. However, MAb D6D8D5 showed various degrees of inhibition of the HA activity of field isolates. In the enzyme-linked immunosorbent assay-competition test, MAb D6D8D5 did not compete with MAb F2E6. MAb B3E6F9 reacted with strain S1, serovar C but not with strain Modesto, serovar C in both dot-blot and HI tests. Three out of 55 field isolates did not react with MAb B3E6F9. Neither MAb reacted with the serovar A and B strains. 相似文献
15.
In order to determine the mutations responsible for virulence, three Croatian field infectious bursal disease viruses (IBDV), designated Cro-Ig/02, Cro-Po/00, and Cro-Pa/98 were characterized. Coding regions of both genomic segments were sequenced, and the nucleotide and deduced amino acid sequences were compared with previously reported full-length sequenced IBDV strains. Phylogenetic analysis, based on the nucleotide and deduced amino acid sequences of polyprotein and VP1, was performed. Eight characteristic amino acid residues, that were common to very virulent (vv) IBDV, were detected on polyprotein: 222A, 256I, 294I, 451L, 685N, 715S, 751D, and 1005A. All eight were found in Cro-Ig/02 and Cro-Po/00. C-Pa/98 had all the characteristics of an attenuated strain, except for glutamine on residue 253, which is common for vv, classical virulent, and variant strains. Between less virulent and vvIBDV, three substitutions were found on VP5: 49 G --> R, 79 --> F, and 137 R --> W. In VP1, there were nine characteristic amino acid residues common to vvwIBDV: 146D, 147N, 242E, 390M, 393D, 511S, 562P, 687P, and 695R. All nine residues were found in A-Ig/02, and eight were found in B-Po/00, which had isoleucine on residue 390. Based on our analyses, isolates Cro-Ig/02 and Cro-Po/00 were classified with vv IBDV strains. C-Pa/98 shared all characteristic amino acid residues with attenuated and classical virulence strains, so it was classified with those. 相似文献
16.
SUMMARY Confirmation of the occurrence of equine herpesvirus type 1 (EHV1) abortion in both epizootic and sporadic form epizootic in Australia for the first time in 1977 against a background in which a reasonably diligent search for such viruses during the preceeding 11 years failed to associate EHV1 with abortion, provided a special opportunity to compare the properties of the newly isolated foetal (F) strains with a collection of endemic respiratory (R) strains that had been recovered at fairly regular intervals since 1967. Using plaque size and host cell range all of 7 R strains tested were clearly distinguishable from 7 of 11 F isolates. The remaining 4 F strains had plaque diameters of R strains but 3 of the 4 viruses conformed in their host cell range with F strains. Only one F isolate (from Tasmania) had both plaque morphology and host cell range of R strain viruses. The mean diameter of plaques produced by R strains in equine foetal kidney (EFK) cells after 4 days under a methyl cellulose overlay was 1.52 mm (range 1.30–1.84 mm) while the mean diameter of small plaques produced by F strains was 0.82 mm (range 0.68–0.91 mm). In addition to EFK cells all R and F strains grew in an equine dermal (EDerm) cell line and all but two of 19 isolates grew in a pig kidney (PK) cell line. None of the low passage R strains grew in bovine embryo tracheal (EBTr) or feline embryo (FEmb) cells whereas all but one of 11 F isolates grew in EBTr cells. 8/11F isolates also grew in FEmb cell line. Growth of viruses at 33° and 40.5°cf. a usual growth temperature of 37° was of no detectable value in differentiating R and F strains of EHV1. In a limited geographic and time frame the criteria of plaque size in EFK cells and growth in EBTr cells unambiguously distinguished between R and F isolates and represent simple markers worthy of additional study. 相似文献
17.
Recombinant DNA probes for Mycoplasma synoviae 总被引：1，自引：0，他引：1
A genomic library was prepared from Mycoplasma synoviae (MS) strain WVU 1853 cloned in plasmid vector pUC8 and transformed in Escherichia coli host JM83. In dot blot assays, four transformed E. coli clones hybridized with 32P-labeled chromosomal DNA of MS but not with 32P-labeled chromosomal DNA of M. gallisepticum (MG) strain S6. In Southern hybridization, each of the CsCl-purified recombinant plasmid clones was shown to contain two MS DNA fragments between 1.0 to 2.3 kbp in length. 32P-Labeled probes prepared from each of the four recombinant plasmids hybridized in dot blot assays with MS strain WVU 1853 and nine MS field isolates but not with MG strains S6, K810, F2F10, four MG field isolates, and 15 other species of avian mycoplasmas. 相似文献
18.
E K Barbour J A Newman J Sasipreeyajan A C Caputa M A Muneer 《Veterinary immunology and immunopathology》1989,21(2):197-206
The antibody response to different proteins of Mycoplasma gallisepticum (MG) was studied in chickens experimentally infected with virulent MG R strain. The chickens were challenged at 8 weeks of age by the intranasal route. Each cockerel received 1.3 X 10(6) colony-forming units (CFU). MG strains (R and F) were banded by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). The banding pattern was distinctively different between the two strains in the range of 92.5 to 200 kilodaltons (kD). Chicken sera collected at different times following challenge were analyzed by Western blot to determine the patterns of antibodies raised to specific MG proteins (R versus F strains). Early in infection (2 weeks postchallenge), antibodies to 60-kD and 75-kD polypeptides of MG R strain were produced. Subsequently (greater than or equal to 4 weeks postchallenge), antibodies recognized a larger number of MG antigens in both strains. The immunoblot patterns remained the same in the period 8-11 weeks postinfection in each of the two strains; however, the patterns were different when the two strains were compared. The early response recognized the 75-kD protein in the R strain while it recognized the 80-kD protein in the F strain. The late response recognized the 130-kD protein and the protein slightly heavier than 200 kD in the R strain. These two bands did not appear in the immunoblot performed against the F strain of MG. Electroeluted protein of MG R strain, namely adhesin (75 kD), showed a hemagglutination activity (HA) on chicken red blood cells. With the appearance of antibodies specific to the 60-kD and 75-kD polypeptides, there was a significant rise in hemagglutination-inhibition geometric mean titer of chicken sera. 相似文献
19.
Antigenic variation of Mycoplasma gallisepticum, as detected by use of monoclonal antibodies. 总被引：8，自引：0，他引：8
V S Panangala M A Morsy M M Gresham M Toivio-Kinnucan 《American journal of veterinary research》1992,53(7):1139-1144
A panel of monoclonal antibodies (MAb) developed against Mycoplasma gallisepticum strain PG31 was used to probe the antigenic profiles of 5 recognized strains (PG31, R, S6, F, A5969) and 6 field isolates of M gallisepticum. Monoclonal antibody G9 predominantly recognized antigens at apparent molecular mass positions of 90 to 98 kDA. The MAb reacted with all strains and isolates, but the molecular mass position of the antigens varied among some mycoplasmas. Monoclonal antibody G12 reacted with all strains and isolates of M gallisepticum and had an identical banding pattern. However, MAb G10 and G11 reacted selectively only with a limited number of strains and/or isolates. Surface distribution of the MAb-recognized antigens was revealed by immunoelectron microscopy. Partial physicochemical characterization of MAb G9-recognized antigens identified glycopeptide characteristics. Monoclonal antibody G9 reacted with surface antigens and, hence, participated in agglutination of M gallisepticum. However, the degree of agglutination varied among the various strains and isolates, indicating a quantitative or conformational limitation or an alteration in the anomeric expression of the epitopes. Antigenic variation in M gallisepticum may be mediated by immunologic selective pressures, or a proclivity for habit niche in the host. 相似文献
20.
Differentiation of Mycoplasma gallisepticum strains using amplified fragment length polymorphism and other DNA-based typing methods 总被引：1，自引：0，他引：1
Hong Y García M Levisohn S Savelkoul P Leiting V Lysnyansky I Ley DH Kleven SH 《Avian diseases》2005,49(1):43-49
Amplified fragment length polymorphism (AFLP) was used to type 34 strains of Mycoplasma gallisepticum (MG) including vaccine strains ts-11, 6/85, and F. Using AFLP, a total of 10 groups, with 30 distinguishable AFLP typing profiles, were generated in the analysis. The AFLP method was able to identify and differentiate both MG field strains from recent outbreaks and those that were epidemiologically related. The AFLP procedure will provide assistance in identifying the sources of mycoplasma infections. Vaccine strains were also differentiated from other field strains, which will be useful in the evaluation of vaccination programs. The AFLP discrimination potential was compared to other molecular typing techniques such as gene-targeted typing by DNA sequence analysis of the MG cytadhesin-like protein encoding gene, mgc2, and random amplified polymorphic DNA assay on the same MG isolates. The three assays correlated well with one another, with AFLP analysis having a much higher discriminatory power and reproducibility. 相似文献