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1.
为了解禽流感病毒(AIV)在我国华南地区的流行情况,我们对活禽市场中分离得到的两株鸭源H6N8亚型AIV[A/duck/Fujian/S2191/2011 (H6N8) (FJ/191/11)和A/duck/Guizhou/S4035/2011 (H6N8) (GZ/035/11)]进行全基因序列测定,并进行其对SPF鸡和BALB/c小鼠的致病性试验.序列分析显示:HA裂解位点基序为339pQIETR ↓GLFG348,为低致病性AIV特征.内部基因分别源于两个国内流行的H6亚型病毒家系(ST339-like和HuN573-like).序列分析表明FJ/191/11和GZ/035/11为H6亚型病毒与其他亚型AIV的N8NA基因发生重组,呈现明显的异源性.两分离株的感染性试验显示,它们对鸡和小鼠均呈低致病性;而且不能在鸡体内有效复制;对小鼠的感染性实验结果显示,小鼠肺脏和鼻甲病毒分离结果为阳性,其他脏器病毒滴定结果为阴性.  相似文献   

2.
本研究对2012年从湖南活禽市场中分离到的一株鸭源H8N4亚型禽流感病毒(AIV)A/duck/HuN/S3160/2012(H8N4)进行全基因组序列和进化分析,并对其进行SPF鸡、SPF鸭和BALB/c小鼠的致病性试验.序列分析显示:HA裂解位点序列为339pSIEPK ↓ GLF347,为典型的低致病性AIV特征.内部基因来源较复杂,HuN/160/12的PB1、NS基因分别与A/spot-billed duck/Xianghai/427/2011 (H5N2)和A/wild bird/Korea/A81/2009(H5N2)的同源性最高,其余内部基因同源性最高的病毒株来自H2、H3、H4、H7、H10等亚型分离株,呈现明显的异源性.感染性试验结果显示,病毒在SPF鸭体内可以通过呼吸道和消化道向外排毒,并且能够在气管、肾脏、盲肠扁桃体及法氏囊检测到病毒,而不能在鸡体内有效复制及排毒.对小鼠的感染性试验结果显示,仅在鼻甲和肺检测到病毒存在,其他脏器病毒滴定结果为阴性,体重呈一过性下降,表明该病毒为低致病性AIV.  相似文献   

3.
2019年11月本实验室从家禽监测样品中分离鉴定到一株低致病性H5N6亚型禽流感病毒(AIV),命名为A/chicken/Hebei/S1/2019(H5N6)(简称CK/HeB/S1/19)。为进一步了解其生物学特点,本实验对其全基因组测序并进行遗传演化分析,结果显示,该病毒属于2.3.4.4h分支,碱性裂解位点为PLRESR↓GLF,属于低致病性AIV(LPAIV)。对其各基因节段分别经BLAST比对后发现,其外部基因来源于H5N6亚型AIV,内部基因完全来源于H9N2亚型AIV,推测该分离株为一株重组病毒。将CK/HeB/S1/19病毒株接种SPF鸡及BALB/c小鼠研究其致病性,结果显示,该病毒虽然能够感染鸡,但不能在鸡体内有效复制,而该病毒未经适应就可在3只小鼠的鼻甲和肺中进行复制,对小鼠呈低致病性。本研究为H5亚型AIV的检测和其感染的综合防控提供了参考依据。  相似文献   

4.
为了解我国首次分离的H13N6亚型禽流感病毒(AIV)生物学特性,本研究对该分离株进行全基因序列测定和分析,并对其进行BALB/c小鼠和SPF鸡致病性试验以及豚鼠传播试验。序列分析表明HA碱性裂解位点序列为PAISNR↓G,为低致病性AIV。遗传进化分析表明NA基因属于北美谱系,其余7个基因均属于欧亚谱系;其中NA、NP、M、NS基因来源于鸥类,而HA、PB2、PB1、PA基因来源于野鸭类。动物致病性和传播试验结果显示,该病毒株在鸡和小鼠体内不能进行有效复制,在豚鼠和鸡体内也不能进行排毒和有效传播。基因序列分析结合致病性和传播性试验表明H13N6亚型AIV分离株可能是通过候鸟迁徙而传入我国的新型重组AIV,但该病毒株仍只能感染野生水禽尚未获得跨越种间屏障感染陆生家禽和人的能力,尚不具备哺乳动物间和家禽间的传播能力。  相似文献   

5.
旨在对2021年分离自我国宁夏回族自治区野鸟粪便中的1株低致病性H7N3禽流感病毒(AIV)A/mallard/Ningxia/Y37/2021(H7N3)株进行了全基因组测序、遗传进化分析及对小鼠致病性试验。全基因组序列分析表明，HA基因裂解位点仅有1个碱性氨基酸，符合低致病性AIV的分子特性。遗传进化分析结果表明，HA基因和韩国野鸭源H7N7亚型AIV同源性较高；NA基因与韩国野鸟源H5N3亚型AIV同源性较高；PB2、PA基因与H5N2亚型AIV有较高的同源性；PB1基因与H5N3亚型AIV有较高的同源性；NP基因与H3N2亚型有较高同源性；M、NS基因与H3N8亚型有较高同源性，具有明显的遗传多样性。血凝抑制(HI)试验结果表明，该毒株与H7N9-Re4疫苗株抗血清的HI效价比同源毒株低16倍，抗原性差异显著。小鼠感染性试验结果显示，该病毒能在小鼠的肺部与鼻甲中复制，并引起感染小鼠体重下降，表明该毒株有感染哺乳动物的风险。本试验通过对1株野鸟源H7N3亚型AIV部分生物学特性的分析，为H7N3亚型禽流感的预警和综合防控提供重要理论参考。  相似文献   

6.
为了解H11N3亚型禽流感病毒(AIV)的生物学特性，本研究对2020年在福州市某活禽市场鸭中分离的一株H11N3亚型AIV进行了全基因组测序、遗传进化分析和对BALB/c小鼠的致病性试验。测序结果显示，分离株HA裂解位点为PAIASR↓GLF，符合低致病性AIV分子特征；HA蛋白226L和228S突变显示病毒具有结合人源受体(SAα-2,6 Gal)的特征性氨基酸。PB1、PA、NP和M1蛋白均出现对哺乳动物致病性增强的特征性氨基酸。遗传进化分析显示，H11N3 AIV的8个基因节段均属于欧亚分支，其HA基因与A/duck/Fujian/SD061/2017 (H11N3)株HA基因序列相似性最高，而NA基因与A/EN/Fujian/02754/2016 (H3N3)株NA基因序列相似性最高。该病毒内部基因分别与浙江、福建和云南等地鸭和鸡体内分离的H7N9、H7N7、H1N2、H7N2、H7N7和H9N6等亚型AIV相关基因高度同源。小鼠致病性试验结果显示，该病毒未经适应即可在小鼠鼻甲和肺脏中高效复制，表明该病毒株具备感染哺乳动物的能力。上...  相似文献   

7.
为进一步了解2014年分离自我国南方野鸟粪便中的一株H9N2亚型禽流感病毒(AIV)Wide Bird/Hu N/SC1400/2014(H9N2)(WB/400/14)的生物学特性,本研究对其进行全基因组序列测定、进化分析及SPF鸡、SPF鸭和BALB/c小鼠的感染性试验。序列分析显示:该分离株的HA裂解位点基序为333PAASDR↓GL340,其中不存在多个连续的碱性氨基酸,符合低致病性禽流感病毒(LPAIV)氨基酸序列特征。该分离株不同基因片段来源较复杂,分别与H9、H6、H4、H1、H11、H10、H3等多种亚型的LPAIV同源性较高,呈现明显的多样性。感染性试验显示,WB/400/14不能够在SPF鸡和小鼠体内有效复制,但病毒感染SPF鸭后能够在部分脏器中检测到病毒的存在,并且感染鸭能通够过咽喉和泄殖腔同时向外排毒,而同居感染鸭仅通过泄殖腔向外排毒,表明分离株在SPF鸭群中具有良好的水平传播能力。本研究为AIV的监测和防控提供实验依据。  相似文献   

8.
为了解H5N3亚型流感病毒的生物学特性,本研究对2017年浙江省分离到的一株H5N3亚型禽流感病毒(AIV)[DK/ZJ/S1368/2017(H5N3)]进行了遗传演化分析及小鼠感染性实验。遗传演化分析结果显示,该株病毒的HA蛋白裂解位点处仅含一个碱性氨基酸,属于低致病性AIV。同时,该病毒的血凝素(HA)基因与H5N7亚型流感病毒亲缘关系较近;聚合酶碱性蛋白2(PB2)基因和核蛋白(NP)基因与H10N7亚型流感病毒亲缘关系较近;碱性聚合酶蛋白1(PB1)基因与H1N1亚型流感病毒亲缘关系较近;酸性聚合酶蛋白(PA)基因与H6N2亚型流感病毒亲缘关系较近;神经氨酸酶(NA)基因与H10N3亚型流感病毒亲缘关系较近;基质蛋白(M)基因与H3N8亚型流感病毒亲缘关系较近;非结构蛋白(NS)基因与H1N1亚型流感病毒亲缘关系较近。表明其基因来源复杂。小鼠感染实验结果显示,该分离株无需提前适应即可以在小鼠肺脏和鼻甲中复制,小鼠感染病毒后无明显临床症状,与对照组相比其体质量变化不明显,表明该病毒对小鼠呈低致病性。本研究通过对该H5N3亚型AIV的生物学特性的分析,发现该病毒基因来源复杂,无需提前适应就可以在小鼠体内复制,具有感染哺乳动物的潜在威胁,提示应当持续加强对H5N3亚型AIV的监测和相关生物学特性的研究工作。  相似文献   

9.
为了解从湖南省某活禽市场分离的一株鸭源H10N1亚型禽流感病毒(AIV) A/duck/Hunan/S10078/2015(H10N1)(简称Hu N/78/15)的生物学特性,本研究对其进行全基因组序列的测定及遗传演化分析,并对其进行BALB/c小鼠的感染试验。序列分析结果显示,该病毒HA基因的裂解位点只含有一个碱性氨基酸,为低致病性AIV (LPAIV)的分子特征。遗传演化分析结果表明该病毒的HA基因与NA基因分别来源于H10N7与H5N1亚型AIV,内部基因来源于H7N9、H4N6、H3N2、H11N7亚型AIV,呈现明显的遗传多样性。小鼠感染试验结果显示,Hu N/78/15能够在小鼠的鼻甲和肺脏中有效复制,但仅引起小鼠轻微的体重变化,表明其对小鼠呈低致病性。本研究结果为H10亚型AIV的持续监测和生物学特性研究提供相应的参考依据。  相似文献   

10.
为进一步了解2015年分离于我国新疆野鸟粪便中的一株H6N6亚型禽流感病毒(AIV)A/WB/XJ/S1541/2015(H6N6)的生物学特性,本研究对其进行了全基因组测序、遗传演化分析以及BALB/c小鼠的感染性试验。序列分析结果显示:该分离株HA蛋白裂解位点的氨基酸序列为~(339)PQIETR↓GL~(346),仅有1个碱性氨基酸,具有低致病性AIV的分子特征。此外,分离株表面基因HA、NA均与一株H6N6亚型猪流感病毒A/swine/Guangdong/K6/2010高度同源,而内部基因均与H6N6亚型AIV A/pigeon/Guangxi/161/2014(H6N6)高度同源,提示该分离株基因来源的多样性。小鼠的感染性试验结果显示:该病毒可在小鼠的肺脏和鼻甲中有效复制,病毒滴度分别为5.33 log_(10) EID_(50)/mL、4.50 log10EID50/m L,提示其具有感染哺乳动物的潜在风险。本研究结果为H6亚型AIV的持续性监测和相关生物学特性的研究奠定基础。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
Tropical Animal Health and Production -  相似文献   

14.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

15.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

16.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

17.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

18.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

19.
The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.  相似文献   

20.
<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.  相似文献   

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