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1.
检测鸭疫里默氏杆菌（Riemerellaanatipestifer,RA）10个基因在不同菌株间的分布并进行序列分析,研究其在不同菌株中的保守性。分别选取8株RA的10个基因进行PCR扩增,扩增产物克隆于pMD18-T载体,进行序列测定和分析。结果显示：测定的8株RA菌株中均能检测到Lipid A、LuxE和TCTR编码基因,表明这些基因在不同血清型RA菌株中的保守性良好;TR基因仅从6株具有致病性的RA菌株中扩增得到,而2株非致病性RA菌株NJ1和NJ4未能扩增到,表明TR基因可能与RA菌株的致病性相关;IS1仅从6株血清1型和2型的RA菌株扩增得到,2株血清10型菌株均未扩增得到,提示IS1为血清10型菌株缺失基因。 相似文献
2.
15 型鸭疫里氏杆菌分离株的鉴定 总被引：9，自引：3，他引：6
鸭疫里氏杆菌 (Riemerella anatipestifer,RA)是鸭传染性浆膜炎的致病病原 ,国际上已报道 2 1个血清型 [1] ,但有人认为 2 0型参考菌株 6 70 /89不属于 RA[2 ] ,故实际上 RA只有 2 0个血清型。国内已出现 1、2、6、1 0、1 1、1 3、1 4型共 7个血清型 [3 ] 。研究表明 ,RA菌苗具 相似文献
3.
为快速检测临床样品中鸭疫里默氏杆菌（RA）,建立检测RA的免疫胶体金方法。以血清1型和2型RA分别免疫BALB／c小鼠,通过细胞融合技术制备单克隆抗体。经ELISA筛选获得4株单克隆抗体2F7、3G9、5G7和2E6,5G7可与1、2、3、11型RA交叉反应,而其他3株与1、2、3型RA有交叉反应。选取单克隆抗体5G7进行纯化和胶体金标记,制备免疫胶体金试纸条,可检测1、2、3、11型RA,而与禽巴氏杆菌、大肠杆菌、沙门菌无反应。对RA模拟样品最低检出剂量为6×10^3 CFU细菌,与细菌分离方法相比,免疫胶体金试纸条对临床病料中RA检测的敏感性为100％,符合率为88．9％。 相似文献
4.
《中国家禽》2016,(16)
从贵州三穗地区某鸭场临床疑似鸭疫里默氏杆菌(Riemerella anatipestifer,RA)感染的病死鸭体内分离得到6株病原菌,经细菌形态观察、生化试验和PCR鉴定确定为RA。对6株RA分离株的血清型鉴定、耐药性及致病性试验,结果表明:6株分离菌中有4株为血清2型,其余2株血清型未定;所有分离株对大环内酯类和氨基糖苷类药物耐药,而对青霉素类和头孢类药物高度敏感;将血清2型RA菌株以9×107cfu/m L剂量经肌肉注射后可导致雏鸭发病死亡,病死鸭表现典型的鸭疫里默氏杆菌病临床症状。结果表明,贵州三穗地区主要流行血清2型RA,且对多种抗生素呈多重耐药且致病性强,应加强对血清2型RA的监测和防控。 相似文献
5.
为研究血清1型鸭疫里默氏杆菌(R.anatipestifer,RA)的灭活油乳剂疫苗,本研究将10株血清1型RA的临床分离株经腿部肌肉注射7日龄雏鸭进行动物体内复壮,结果表明所有被测菌株均具有较强的毒力,易感雏鸭致死率100％.对其中3株RA分离株CH3、WJ4和YL4的毒力测定结果表明其半数致死量(LD50)分别为2×108 cfu、3.25×108 cfu和2.37×106 cfu.选取5株RA分离株分别制备灭活油乳剂疫苗,分别于5日龄和18日龄对樱桃谷鸭进行两次免疫后,免疫鸭能够产生高水平的RA特异性抗体,对2 LD50 WJ4或CH3攻毒产生很好的保护效果,其中由CH3、CQ3和YXb12制备的灭活油乳剂疫苗对攻毒的保护率高达100％. 相似文献
6.
在广东省水禽养殖较密集的肇庆地区选择4个鸭疫里氏杆基本国策4 病发病鸭场和1个未发病鸭场，采集病料，进行病原分离，并用玻片凝集试验和琼脂扩散试验检测分离株的血清型。结果表明，该地区流行的鸭疫里氏杆菌（RA）仍以1型为主，但有1株与RA1型抗血清无交叉反应。对RA分离株进行8种抗生素的敏感性试验显示，分离株对丁胺卡那霉素极度敏感，对头孢唑啉、新霉素、头孢氨苄高度敏感，对氯霉素、卡那霉素、庆大霉素、恩诺沙星有不同程度的抗药性。 相似文献
7.
3型鸭疫里氏杆菌的分离与鉴定 总被引：3，自引：0，他引：3
采集福州市北郊某番鸭场接种过1型和2型鸭疫里氏杆菌（RA）双价灭活疫苗而发病死亡的雏鸭肝，从中分离到1株RA，经对分离菌培养特性、形态观察和血清型鉴定，属3型RA。 相似文献
8.
鸭疫里氏杆菌优势血清型变化的研究 总被引：2，自引：3，他引：2
近年来，从浙江省及其周边地区鸭场患有传染性浆膜炎的病死鸭中分离鉴定出的77株鸭疫里氏杆菌，用标准定型血清作凝集试验，鉴定出：RAⅠ型33株，RAⅡ型33株，二者共占总分离茵数的85．7％，而未定型茵11株，占14．3％。结果表明：RA的优势血清型在不同的时间出现不同的变化：1998年以前为单一的RAⅠ型：1999～2000年以RAⅠ为主，占总分离茵数的51．9％；2001年以RAⅡ型占绝对优势，占总分离菌数的89．5％；而到了2002年，未定型的菌株数增加到了33．3％。同时也证明：该地区的优势血清型为RAⅠ、Ⅱ型。 相似文献
9.
7型鸭疫里氏杆菌分离株的鉴定 总被引：14，自引：6，他引：8
鸭疫里氏杆菌(Riemerella anatipestifer,RA)是鸭传染性浆膜炎的致病病原,国际上已报道20个血清型,我们在国内也已发现1、2、6、10、11、13、14、15、17型共9个血清型。对RA分离株的血清型进行鉴定是研究鸭传染性浆膜炎流行病学的内容之一,其结果对于制定有效的免疫程序是至关重要的。2002年,我们从北京某鸭场共分离到4株RA,经鉴定为7型,这在国内尚属首次发现,因而将有关试验情况报告如下。 相似文献
10.
11.
The experimental induction of pneumonic pasteurellosis in groups of conventionally reared lambs by 8 serovars (A1, A2, A6, A7, A8, A9, T10, and A11) and untypable (UT) strains of Mannheimia haemolytica (Mh) were examined and compared. The groups of lambs were inoculated intratracheally with 1.4 x 10(8) +/- 0.6 x 10(8) (mean +/- SD) colony-forming units of the Mh serovars or UT isolates in the 6-hour log phase of growth. The variables measured as indicators of disease severity were clinical score, percentage lung consolidation and microbiological re-isolation. The clinical parameters for each group were computed daily for 6 days post infection and the lambs which died were necropsied while the remaining lambs were killed on day 7 pi and the extent of lung consolidation was measured. Clinically, the mean scores for the M. haemolytica serovars were A1 (6.1), A2 (18.8), A6 (0.5), A7 (17.4) and A9 (8.5). The mean percent lung lesion scores for M. haemolytica serovars were A1 (12.5), A2 (66.3), A6 (5.0), A7 (51.3), A9 (33.8) and A11 (2.5). The percent mean pneumonic lung lesions recorded for groups inoculated with A2, A7 and A9 were significantly (P < 0.05) higher than the extent of lung lesions in the other groups. A statistically significant correlation was observed between clinical scores and the severity of the lung lesions (r = 0.96, P < 0.01). High titres of M. haemolytica were recovered from lung lesions, with 10 to 100 times the number of organisms inoculated being present in the lung lesions of lambs inoculated with serovars A2 and A7. These data indicate that although M. haemolytica serovars A1, A2, A6, A7, A9 and A11 are important primary lung pathogens of lambs, serovars A2, A7, and A9 are to be regarded as highly virulent strains that have a greater predilection than the other serovars for causing pneumonia in lambs. 相似文献
12.
The aim of this study was to investigate beta-casein polymorphism among 320 Japanese cows sampled from eight dairy farms. We used a newly-developed genotyping method that involved collecting DNA from hairs and a Cycleave polymerase chain reaction (PCR) assay to detect the A1, A2, and B variants. Results revealed the presence of five genotypes (A1A1, A2A2, A1A2, A1B, and A2B). We found that the most common genotype was A2A2 (0.42), followed by A1A2 (0.39) and A1A1 (0.11). The A1B and A2B genotypes were less frequent (<0.05). The frequencies of alleles A1, A2, and B were calculated to be 0.32, 0.64, and 0.04, respectively. Our study is the first to show the current status of beta-casein polymorphisms in Japanese dairy farms. Given the adverse effects of A1 beta-casein on human health, attempts have been made to develop herds consisting solely of A2A2 cows. Our study provides a reference for improving cow populations in Japanese dairy farms. The Cycleave PCR-based assay we developed here can be used for rapid and reliable genotyping of bovine beta-casein. 相似文献
13.
上海崇明白山羊具有高繁殖率的优良特性,为探索这一特性的遗传基础,本研究利用PCR-SSCP联合PCR产物测序的方法分析了gdf-9基因的多态性,结果发现在崇明白山羊gdf-9基因的编码区内存在3处多态位点,分别为A183C、G1188A和G1189A。其中G1188A变异位点在其他山羊中尚未有报道。经氨基酸编码分析,A183C和G1188A处的多态性未造成氨基酸的编码改变,G1189A处的G→A多态变化导致了缬氨酸→异亮氨酸的改变。两相邻多态位点G1188A和G1189A的产仔率分析结果表明:在75只崇明白山羊中,G1188A位点的3种等位基因型G(G)、G(A)和A(A)的基因频率分别为86.67%、13.33%和0;G1189A位点的3种等位基因型G(G)、G(A)和A(A)的基因频率分别为60.00%、40.00%和0;G1188A位点处G(G)型个体产仔数的最小二乘均值大于G(A)型个体(P>0.05);G1189A位点G(A)型个体的平均产仔数大于G(G)型个体(P>0.05)。综合G1188A和G1189A两个位点,不同基因型的最小二乘均值关系为AC>AA>AB,但3种基因型间差异不显著(P>0.05)。综上结果,崇明山羊gdf-9基因变异位点的多态性对产仔数没有显著性影响。 相似文献
14.
del Río ML Martín CB Navas J Gutiérrez-Muñiz B Rodríguez-Barbosa JI Rodríguez Ferri EF 《Research in veterinary science》2006,80(1):55-61
The Haemophilus parasuis aroA gene encodes 5-enolpyruvylshikimate-3-phosphate synthase and participates in the aromatic amino acids and the folic acid universal metabolic pathway of bacteria. The application of aroA-based PCR-RFLP methodology yields a significant degree of diversity in H. parasuis and Actinobacillus species. PCR amplification of the aroA gene rendered a 1,067-bp fragment in all 15 H. parasuis serovars, and also in Actinobacillus pleuropneumoniae serotypes 1-12, Actinobacillus lignieresii, Actinobacillus equuli, Actinobacillus porcinus, Actinobacillus rossii, Actinobacillus suis, Actinobacillus ureae, Actinobacillus minor and Actinobacillus indolicus. Sau3AI and RsaI digestions of the aroA PCR products rendered seven different restriction fragment length polymorphism (RFLP) patterns: group I (H. parasuis serovars 1, 2, 4-6, and 8-15, A. porcinus and A. ureae), group II (H. parasuis serovars 3 and 7, and A. pleuropneumoniae serotypes 1, 4, 5, 9, 11 and 12), group III (A. lignieresii), group IV (A. pleuropneumoniae serotype 7), group V (A. pleuropneumoniae serotypes 2, 3, 6 and 8, A. equuli, A. rossii, A. minor and A. indolicus), group VI (A. suis) and group VII (A. pleuropneumoniae serotype 10). This is the first report describing the presence of aroA gene in H. parasuis, A. lignieresii, A. porcinus, A. rossii, A. suis, A. ureae, A. minor and A. indolicus and the data presented here demonstrates a significant degree of aroA genetic diversity in H. parasuis and species of the genus Actinobacillus. 相似文献
15.
Effects of level and frequency of supplementation with alfalfa (A) on feed intake and digestion by steers fed bermudagrass (B) or orchardgrass (O) were determined in two Latin square experiments. In Exp. 1, six Holstein steers (224 kg) were fed B (2.25% N; 71.4% NDF) or O (2.52% N; 64.3% NDF) with 0, 15 or 30% (DM) A (2.70% N; 44.0% NDF). Total DMI was 2.43, 2.72 and 2.85% BW for B and 2.98, 3.00 and 2.87% BW for O with 0, 15 and 30% A, respectively. Total DMI was affected by forage (P less than .05), A level (linear; P less than .06) and a forage x A level (linear) interaction (P less than .05). Digestible OM intake increased .42 (15%) and .67 kg (24%) with feeding of 15 and 30% A, respectively, for B, but for O, only dietary inclusion of 30% A elevated digestible OM intake (.14 kg and 4% increases). In Exp. 2, five Holstein steers (165 kg) were fed B (1.81% N; 78.6% NDF) alone or with A (2.76% N; 52.8% NDF). Morning meals consisted of ad libitum B (OA), .3% BW of A daily (.3A), .6% BW of A every 2nd d (.6A), .9% BW of A every 3rd d (.9A) or 1.2% BW of A every 4th d (1.2A). All steers received B in the afternoon ad libitum, and B was given in the morning when A was not fed. Total DMI was 2.31, 2.12, 2.12, 2.26 and 2.29% BW for OA, .3A, .6A, .9A and 1.2A, respectively (SE .049). Grass characteristics affected response in feed intake to legume supplementation. Frequency of dietary legume addition may alter feed intake. 相似文献
16.
A total of 343 calves (males and females) were evaluated for preweaning average daily gain, weaning weight (WW), feedlot average daily gain to slaughter (ADGF), slaughter weight (SW), pelvic height (PH), pelvic width, pelvic area, weaning conformation score (WS) and ratio of weaning weight to the dam's weight at weaning (R). Mating types included straight-bred Angus (A) and Santa Gertrudis (S), the reciprocal crosses of these two breeds and Gelbvieh (G) X Angus. Straightbred S and A X S crosses had the heaviest WW, followed by S X A and G X A crosses; straightbred A had significantly smaller WW than all other mating types. The crossbreds and the straightbred S had higher WS than straightbred A. The ratio of WW to cow weight was largest for S X A. The straightbred S and A X S crosses had significantly lower R values than the other mating types. Weaning weight per cow exposed, computed as the product of weaning rate and weight, indicated that straightbred A had an advantage over the other mating types (156.5 kg), whereas S and S X A were intermediate (147.9 and 147.6 kg, respectively) and A X S was lowest (128.9 kg). Feedlot gain was highest for A X S, though not significantly greater than for straightbred S or G X A. Straightbred A gained significantly less than other mating types except S X A. Straightbred A were found to be significantly smaller at slaughter than the other mating types. The S X A and G X A were intermediate; the straightbred S and A X S were significantly larger for SW.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
17.
２，４-二叔丁基苯酚对啤酒花幼苗生长与光合特性的影响 总被引：3，自引：2，他引：1
前期对不同植龄啤酒花根系分泌物及根际土壤的化学物质进行了分离鉴定,结果发现有酚类物质的存在且２,４-二叔丁基苯酚含量较高,为了进一步证实啤酒花是否存在自毒作用,采用田间小区栽培试验,研究了不同用量［０（ＣＫ,Ａ０）,７．５（Ａ１）,１５．０（Ａ２）和２２．５ｍｍｏｌ／ｍ２（Ａ３）］２,４-二叔丁基苯酚处理对啤酒花幼苗生长及光合特性的影响。结果表明,２,４-二叔丁基苯酚用量Ａ１ 和Ａ２ 处理,啤酒花生长好,地上部、地下部、总生物量及日均光合速率均比对照高,且达到显著差异（犘＜０．０５）;２,４-二叔丁基苯酚用量Ａ３ 处理,啤酒花地上部、地下部和总生物量及光合特性均较对照降低,差异达到显著水平（犘＜０．０５）。啤酒花幼苗叶片光合速率日变化呈双峰型,最高峰出现在上午９：００左右,次高峰出现在中午１５：００左右,午间有明显的“午休“现象,与对照（Ａ０）相比,Ａ１、Ａ２、Ａ３ 三个处理的次高峰出现的时间均有推迟,且Ａ１ 和Ａ２ 处理的幼苗午休”现象不太明显,气孔因素是导致其“午休”的主要原因。 相似文献
18.
Avian leukosis virus subgroup A (ALV‐A) is a retrovirus which infects egg‐type chickens and is the main pathogen of lymphoid leukosis (LL) and myeloid leukosis (ML). In order to greatly enhance the diagnosis and treatment of clinical avian leukemia, two monoclonal antibodies (MAbs) to ALV‐A were developed by fusion between SP2/0 and spleen cells from mice immunized with expressed ALV‐A env‐gp85 protein. Using immunofluorescence assay (IFA), two MAbs reacted with ALV‐A, but not with subgroups B and J of ALV. Western blot tests showed that molecular weight of ALV‐A envelope glycoprotein recognized by MAbs was about 53 kD. Isotyping test revealed that two MAbs (A5C1 and A4C8) were IgG1 isotypes. These MAbs can be used for diagnosis and epidemiology of ALV‐A. 相似文献
19.
以黄河源区果洛州玛沁县建植14年的垂穗披碱草 (Elymus nutans) 栽培草地为研究对象,针对以甘肃马先蒿 (Pedicularis kansuensis) 和黄帚橐吾 (Ligularia virgaurea) 为主的阔叶型毒杂草,选择6种除草剂及5种复配剂进行防除试验,6种除草剂为单一除草剂,即2, 4-滴丁酯(A)、使它隆(B)、龙拳(C)、阔诺(D)、刹阔(E)、苯磺隆(F) ;5种复配剂为2, 4-滴丁酯与其他除草剂的复配剂,即(A + B)、(A + C)、(A + D)、(A + E)、(A + F)。结果表明,喷施B、F、A + E除草剂不同程度地降低黄帚橐吾的高度、盖度及生物量,且F和A + E对生物量影响显著 (P < 0.05) ;A、E、F、A + B、A + C和A + F 6种除草剂显著降低了甘肃马先蒿的高度、盖度及生物量(P < 0.05);复配除草剂A + F能有效防除群落毒杂草,防除等级达到最高3级,A + E处理下牧草的盖度和生物量显著高于对照 (P < 0.05);喷施除草剂群落物种丰富度指数、Shannon-Wiener指数呈下降趋势,但均匀度指数比对照略高。通过鲜重防效评价了11种处理的防除效果,结果表明,防除黄河源区栽培草地的毒杂草可选择A + E、F、A + F 3种除草剂。 相似文献
20.
选取6只安装永久瘤胃瘘管羯羊(白萨福克♂×小尾寒羊♀)为瘤胃液供试动物,采用4×6二因子析因试验设计,共设2个因子,分别为不同精粗比日粮(A1(20:80)、A2(30:70)、A3(40:60)、A4(50:50))和不同甘露寡糖添加量(B1 (0)、B2 (0.4%)、B3 (0.8%)、B4 (1.2%)、B5 (1.6%)、B6 (2.0%)),进行尼龙袋半体内试验,旨在研究不同精粗比日粮中添加甘露寡糖对绵羊瘤胃中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)降解率的影响。结果表明,A因子对日粮中不同时间点NDF、ADF瘤胃降解率、降解参数及有效降解率均产生了显著影响(P< 0.05),A1处理组的NDF和ADF各个时间点(除3 h外)的瘤胃降解率均显著高于A3和A4处理组(P< 0.05);B因子对3、6、9、12、48 h的瘤胃ADF降解率均产生了显著影响(P< 0.05),其中B5处理组显著高于B1、B2处理组(P< 0.05);A3处理组的NDF有效降解率显著高于A1、A2处理组(P< 0.05),稍高于A4处理组(P >0.05)。综上所述,在精粗比为40:60时,NDF和ADF的瘤胃有效降解率处于较高水平。 相似文献