2株鸭源 H11N9亚型禽流感病毒的基因遗传进化及致病性分析     

谭丹  黄建龙  王昌建  何世成  王卫国  唐小明  朱春霞  范仲鑫  汪洪冰  刘道新  邓国华 《动物医学进展》2015,(2)

为了解从湖南省洞庭湖区鸭群中分离的2株 H11N9亚型禽流感病毒变异特点、进化规律及生物学特性,本研究对2株H11N9亚型禽流感病毒的HA、NA序列进行同源性和遗传进化分析,并用2株毒株对SPF鸡进行致病性试验。结果显示,本试验分离到2株 H11N9亚型禽流感毒株的 HA裂解位点均没有多个连续的碱性氨基酸插入,属于低致病性毒株;HA基因的受体结合位点均非常保守,具有典型的禽源性特征;NA基因序列与在周边国家野鸟中分离的H11N9亚型毒株的氨基酸同源性较高;鼻腔接种SPF鸡后,均能使鸡感染并通过喉头或泄殖腔排毒,但感染的鸡均不表现明显的临床症状,并且不能使同居鸡感染排毒。  相似文献   

肺炎克雷伯氏菌强毒株的分离鉴定及16-23SrRNAITS序列分析   总被引：1，自引：1，他引：0  

李富祥  李华春  赵德宏  王娟  姚俊  廖德芳  熊和丽  宋建领  胡骑 《中国畜牧兽医》2015,42(2):352-357

为确诊疑似仔猪肺炎克雷伯氏菌(K.pneumonia)感染,并研究其病原的致病性、耐药性、16-23SrRNA ITS系统进化特征,本研究从云南因肺炎、腹泻而大量死亡的仔猪中分离到1株革兰氏阴性短粗杆菌,命名为KP14013,对其进行生化鉴定、16SrRNA鉴定,研究其对小白鼠和仔猪的致病性,并对其16-23SrRNA ITS基因进行测序和遗传进化分析。结果显示,KP14013分离株生化特征与肺炎克雷伯氏菌相符,其16SrRNA与GenBank中23株肺炎克雷伯氏菌代表株之间的同源性均为99%,将KP14013鉴定为肺炎克雷伯氏菌。KP14013对小白鼠半数致死量(LD50)为3×101.8 CFU,腹腔注射3×108 CFU可使仔猪100%致死。16-23SrRNA ITS系统进化关系结果表明,KP14013与GenBank中收录的15株肺炎克雷伯氏菌形成进化树的一个分支,属于同一个亚群,它们之间的核苷酸同源性为98.4%~99.2%。本研究证实了肺炎克雷伯氏菌是该起仔猪腹泻大量死亡的病原;KP14013分离株为毒力极强菌株,具有多重耐药性,其16-23SrRNA ITS与GenBank中收录的肺炎克雷伯氏菌代表株之间核苷酸存在差异,可用于肺炎克雷伯氏菌菌株间的鉴别。  相似文献   

Isolation,Identification and Multidrug-resistant Analysis of the New Sequence Type ST989 Strain of Enterococcus faecium     

ZHANG Fen-fen  LI Xue-rui  YANG Jian-she 《中国畜牧兽医》2015,42(5):1274-1282

Gram-positive cocci were isolated from half a month diseased lambs with a fatal infection in a sheep farm in Minhe county, Qinghai province.The clinical symptoms observed were drooping, reduced feed intake, emaciated and fever.The infected lambs died several hours after the disease been observed.Necropsy of two dying lambs revealed that for one lamb, the liver was enlarged and capsule of the liver dropped, and other organs had no obvious changes;For the other one, the organs had no obvious changes.After gram staining, gram-positive cocci were observed from all the samples.Partial Tuf gene sequences of these isolates were amplified and sequenced for species identification, BLASTn conparison result revealed that they had the highest sequence similarity with that of Enterococcus faecium (E.faecium) AUS0085 (99.8%), we thus primarily confirmed that these strains belonged to E.faecium.Antimicrobial susceptibility test indicated that these strains could be divided into two classes.Class 1 was resistant to β-lactams, aminoglycosides, macrolides, tetracyclines, quinolones, rifamycins, lincomycin and clindamycin;Susceptible to chloromycetin and vancomycin.Class 2 was resistant to β-lactams, aminoglycosides, tetracyclines, quinolones, rifamycins;Intermediate resistance to erythromycin and roxithromycin;But susceptible to clarithromycin, azithromycin, clindamycin, lincomycin, chloromycetin and vancomycin.Multilocus sequence typing (MLST) based on seven housekeeping genes for E.faecium revealed that E.faecium lby1 strain in class 1 and E.faecium lbg3 strain in class 2 were defined as a new sequence type ST989.Phylogenetic tree analysis revealed the representative strain of these isolates, E.faecium lbg3, was clustered together with E.faecium ST468.The pathogenicity test revealed that E.faecium lby1 and lbg3 strains both had pathogenicity.  相似文献   

Isolation,Identification and Analysis of Serotype and Antibiotic Susceptibility of Pathogenic Salmonella from Chickens     

SHI Kai-chuang  LI Feng-mei  ZOU Lian-bin  XU Xin-ting  WANG Hai-qing  ZHONG Cheng 《中国畜牧兽医》2015,42(8):2160-2168

To investigate the situations of predominant strain and antibiotic resistance of pathogenic Salmonella from chickens in Guangxi Zhuang Autonomous region, Salmonella was pre-enriched and isolated from tissues of clinical suspected chickens, and the Salmonella isolates were identified by biochemical test using ID 32E System for the identification of Enterobacteriaceae of VITEK System ATB Expression, serotypes were determined by slid agglutination test, antibiotic susceptibility was analyzed by ATB VET Susceptibility Test Strip of Enterobacteriaceae antibiotics.The results showed that 34 Salmonella strains were obtained from 310 clinical samples, of which 1 strain belonged to A serogroup, 1 to C2 serogroup, 15 to B serogroup, 14 to D serogroup and 3 to untyped serogroup, and S.typhimurium of B serogroup and S.pullorum of D serogroup were the predominant serotypes.All Salmonella isolates were sensitive to meropenem, imipenem, spectinomycine and apramycine, and the resistance rates to chloramphenicol, kanamycine and gentamicine were less than 10%, and the resistance rates to amoxicillin, streptomycine, flumequine, oxolinique, sulfamethizol, tetracycline and nitrofurantoine ranged between 50% and 90%, while the resistance rates to penicilline, oxacilline, fusidique, rifampicine and metronidazole reached to 100%.The results indicated that the serotype distribution of pathogenic Salmonella from chickens exhibited regional characteristics, and S.typhimurium and S.pullorum were the predominant serotypes in Guangxi Zhuang Autonomous region, and antibiotic resistance of Salmonella isolates was very serious which should be highly concerned.  相似文献   

丁型流感病毒在中国的流行状况及研究进展     

余界石  魏文康 《广东农业科学》2022,49(11):1-8

丁型流感病毒是继甲型、乙型和丙型流感病毒之后的一种新型正粘病毒,2011 年首次由美国从表 现出流感样症状的猪只中分离出来,并于 2016 年被国际病毒分类委员会正式命名为丁型流感病毒。目前丁型流 感病毒已广泛分布于美洲、亚洲、欧洲和非洲的数十个国家。丁型流感病毒利用牛作为其自然宿主和扩增宿主, 并定期扩散到其他哺乳动物物种,包括猪、马、羊和骆驼等。因此,丁型流感病毒具有广泛的地域分布和宽泛 的宿主范围。丁型流感病毒感染可导致牛患轻度至中度呼吸道疾病,被认 为是牛呼吸系统疾病综合征的重要关 联因子。血清学证据表明,丁型流感病毒具有感染人的潜在风险。我国研究人员于 2014 年首次在山东省的牛群 中检测到丁型流感病毒,随后,来自不同团队的研究人员分别于 2017、2021 和 2022 年报道了丁型流感病毒核 酸阳性病例。为更好地了解丁型流感病毒对我国畜牧养殖业的影响,系统综述了丁型流感病毒在我国的分布情 况和研究进展,并分析 了丁型流感病毒在我国的流行趋势及对我国畜牧养殖业的潜在威胁。  相似文献   

Involvement of the autophagy-related gene BdATG8 in development and pathogenicity in Botryosphaeria dothidea          下载免费PDF全文

LIU Na  LIAN Sen  ZHOU Shan-yue  WANG Cai-xia  REN Wei-chao  LI Bao-hua 《农业科学学报》2022,21(8):2319-2328

Botryosphaeria dothidea is a destructive fungal pathogen that causes Botryosphaeria canker and fruit ring rot on apple worldwide. Autophagy is a process of self-degradation that maintains intracellular homeostasis via lysosomal pathway. To date, the biological role of autophagy in B. dothidea remains unknown. In this study, we identified and characterized the autophagy-related gene BdATG8 in B. dothidea. BdATG8 was able to restore the defect in nitrogen starvation tolerance of Saccharomyces cerevisiae ATG8 deletion mutant. GFP-BdAtg8 was shown to be a useful marker for monitoring autophagy in B. dothidea. Target deletion of BdATG8 (ΔBdAtg8) blocked autophagy and significantly impaired mycelial growth, conidiation and perithecium formation. In addition, ΔBdAtg8 showed significantly increased sensitivity to phytoalexin and oxidative stress, suggesting that BdATG8 plays critical roles in overcoming phytoalexin and reactive oxygen species (ROS)-mediated plant immunity. Pathogenicity assays revealed that ΔBdAtg8 almost lost ability to infect hosts. Overall, our results indicate that BdATG8 plays an important role in fungal development, stress responses and pathogenesis in B. dothidea.  相似文献   

Neopestalotiopsis eucalypti,a causal agent of grapevine shoot rot in cutting nurseries in China          下载免费PDF全文

MA Xuan-yan  JIAO Wei-qi  LI Heng  ZHANG Wei  REN Wei-chao  WU Yan  ZHANG Zhi-chang  LI Bao-hua  ZHOU Shan-yue 《农业科学学报》2022,21(12):3684-3691

Grapevine (Vitis vinifera L.) is an economically important fruit crop in the world, and China ranks first in the production of grapes with approximately 15% of the world's total yield. However, diseases that cause the death of grapevine shoots pose a severe threat to the production of grapes. In this study, the fungus Neopestalotiopsis eucalypti was identified as a causal pathogen of grapevine shoot rot based on the morphology of conidia and a phylogenetic analysis. The phylogenetic analysis was performed with three isolates based on the combined sequence of internal transcribed spacer (ITS) region of ribosomal DNA, part of the translation elongation factor 1-alpha (Tef) and the β-tubulin (Tub2) genes. The three isolates were all identified as N. eucalypti. Pathogenicity tests of the three fungal isolates were conducted on grapevines shoots in vitro and in vivo. The results showed that all three fungal isolates caused severe rot lesions on the inoculated grapevine shoots, and N. eucalypti was re-isolated from the inoculated grapevine shoots. Therefore, N. eucalypti was confirmed as a causal agent of the grapevine shoot rot. This is the first report of N. eucalypti causing grapevine shoot disease in China.  相似文献   

大口黑鲈鲁氏耶尔森氏菌的分离鉴定、主要毒力基因及致病性研究     

王巧煌  林楠  元丽花  季静  林丹 《水产学报》2022,46(5):825-835

为探明2021年3月福建某水库养殖大口黑鲈疾病暴发的原因,实验从患病大口黑鲈肝脏、肾脏、脾脏中分离优势菌,通过人工感染实验确定病原菌,并综合16S rDNA基因序列分析、生理生化和质谱特征等技术对该病原菌进行种属鉴定,同时,进行毒力基因检测、药物敏感性实验以及组织病理学观察。结果显示,从病鱼脾脏中分离获得1株优势菌并鉴定为鲁氏耶尔森氏菌;该菌株对大口黑鲈的半致死剂量为3.8×10⁵ CFU/尾;该菌株携带yrP1、yhl A、yhl B等毒力基因,对恩诺沙星、盐酸多西环素、氟甲喹、硫酸新霉素、氟苯尼考等5种药物相对敏感。组织病理学观察发现,鲁氏耶尔森氏菌的感染造成大口黑鲈肝脏、肾脏、脾脏不同程度的损伤,表现为明显的变性、坏死及炎症细胞的浸润等。本研究首次报道了鲁氏耶尔森氏菌对养殖大口黑鲈的致病性,可为养殖大口黑鲈鲁氏耶尔森氏菌病的诊断和药物防治提供参考依据。  相似文献   

Molecular characterization and pathogenicity of a grouper iridovirus (GIV) isolated from yellow grouper, Epinephelus awoara (Temminck & Schlegel)     

S Murali  M-F Wu  I-C Guo  S-C Chen  H-W Yang  & C-Y Chang 《Journal of fish diseases》2002,25(2):91-100

Molecular characterization was carried out on an iridovirus isolated from yellow grouper, Epinephelus awoara . The major capsid protein (MCP) gene was located, sequenced and compared with homologous genes from other iridoviruses. The nucleotide sequence is 1392 bases long and contains a single open reading frame beginning at an ATG codon from the 5' end and terminating at a TAA codon at the 3' end. The open reading frame encodes a protein of 463 amino acids with a predicted molecular weight of 50 272 Da. Pairwise amino acid alignments detected a high degree of sequence identity between grouper iridovirus (GIV) MCP and the homologous genes of other iridoviruses. The MCP gene of GIV was most similar to the MCP gene from frog virus 3 (FV3) with 70% nucleotide and 73% amino acid sequence identity. The predicted molecular weight of the protein of this gene is comparable with the apparent weight obtained by SDS–PAGE. Pathogenicity of the GIV was investigated in yellow grouper by intraperitoneal injection of 10⁷ and 10⁴ TCID₅₀ virus. Cumulative mortalities reached 100% within 11 and 25 days post-infection, respectively, while no grouper died in the control group. The molecular studies demonstrated that GIV is a member of the genus Ranavirus .  相似文献   

一株GPV的分离鉴定及致病性研究     

饶桂波  邵洪泽  胡桂学  吴健敏 《家畜生态》2014,(1):49-53

为了确定导致吉林省某地区10日龄雏鹅发病的病原,从病死雏鹅的肝脏中分离到一株病毒,根据病毒的电镜照片,动物回归试验及PCR鉴定,确定为鹅细小病毒。PCR产物测序后经BLAST比对显示,分离毒株与NCBI收录的GPVVP3基因同源性均在92％以上,与GPV／CH／HLJ02／08VP3基因的同源性最高,达99％。致病性研究表明,分离株的ELD50为10^-6.5／0．2mL,毒力较强,且该毒株能被GPV标准血清所中和。  相似文献