鸭疫里默氏杆菌的鉴定及药敏试验

从四川某鸭场送检的病料中分离到1株疑似鸭疫里默氏杆菌(Riemeralla anatipestifer,RA)。经细菌形态学、培养特性、生化试验、PCR扩增与动物回归试验鉴定后,证实为鸭疫里默氏杆菌。该菌尿素酶试验阳性,不能发酵多种糖类,不能液化明胶,不产生H2S,不还原硝酸盐,吲哚试验、MR试验、VP试验均为阴性;菌株对左氟沙星、氧哌嗪青霉素、庆大霉素等极为敏感,而对青霉素、头孢拉定、链霉素等耐药。     

桑树1,5-二磷酸核酮糖羧化酶活化酶基因cDNA片段的克隆及原核表达与植物反义表达载体的构建

1,5-二磷酸核酮糖羧化酶活化酶(RCA)对桑树的光合作用具有重要调节作用。以桑树幼叶为材料分离mRNA,反转录合成cDNA,以cDNA第1链为模板,根据RCA的保守区域设计1对兼并引物,经PCR扩增获得RCA的基因功能区中间片段。对得到的桑树RCA的cDNA片段编码氨基酸进行BLAST分析表明,其与GenBank中其它植物来源的RCA有较高同源性。将RCA的部分编码区插入原核表达载体pET30a(+),并转化到大肠杆菌菌株BL21中,经IPTG诱导,RCA的部分编码区在BL21菌株成功表达。将得到的RCA基因片段反向插入植物表达载体,构建了RCA基因反义表达载体pBI121-RCA,以利于进一步阐明RCA与1,5-二磷酸核酮糖羧化酶相互作用和调控关系以及用基因工程手段深入探讨桑树光合作用机制。     

Granulocytic anaplasmosis in three dogs from Saskatoon,Saskatchewan

Three dogs from Saskatoon, Saskatchewan were diagnosed with acute granulocytic anaplasmosis. Fever, lethargy, inappetence, vomiting, diarrhea, and lameness were reported. Lymphopenia, thrombocytopenia, and splenomegaly were identified in all dogs. Inclusions were identified within the cytoplasm of blood neutrophils, and infection with Anaplasma phagocytophilum was confirmed by polymerase chain reaction.     

Heritability of juniper consumption in goats

Data from goats (n = 505), collected over a 4-yr period, were used to estimate the heritability of juniper consumption. Juniper consumption was determined by near-infrared spectroscopy on fecal samples (n = 1,080) collected from female Boer-cross goats grazing pastures with a variety of plants, including juniper. The animals with records were progeny of 72 sires. Individual goats had from 1 to 4 observations over a 4-yr period. Predicted juniper consumption for individual observations ranged from -5 to +62% of the diet. Data were analyzed with a mixed model that included management group as a fixed effect, BW as a covariate, and permanent environment, animal, and residual as random effects. Management group was a significant source of variation. Least squares means of juniper consumption, as a percentage of the total intake, for management groups varied from 19 to 47%. Heritability of juniper consumption was 13%. Repeatability of juniper consumption was 31%. These results suggest that progress to selection for goats that will consume greater amounts of juniper is obtainable, but is expected to be slow.     

复方中药多糖对雏鸡免疫功能的影响

随着畜牧业日趋集约化,采取各种措施以提高机体免疫力在畜禽传染病控制方面显得日益重要.通过疫苗免疫来控制疾病的发生是非常重要而有效的手段,但是免疫失败或免疫抑制的情况时有发生.中药免疫增强剂因其资源丰富、作用广泛、标本兼治、安全低毒、不易产生耐药性、无污染、无残留等特点,具有营养与保健的双重功能[1],因此成为当前国内外研究的热点.     

Growth pattern and partial proteome of Mycobacterium avium subsp. paratuberculosis during the stress response to hypoxia and nutrient starvation

Mycobacterium avium subsp. paratuberculosis is an important pathogen that causes Johne's disease in animals and has been implicated in Crohn's disease in man yet few data exist on its physiological adaptation in either the host or the environment. In this study, the proteomic responses of the two distinct strains of M. a. paratuberculosis, cattle (C) and sheep (S), to hypoxia and starvation were studied in vitro. Nutrient starvation inhibited growth of both strains and was lethal for S strain after 12 weeks. Hypoxia induced a state of very low metabolic activity but rapid resuscitation occurred upon restoration of an aerobic atmosphere, consistent with the dormancy response of other mycobacteria. A total of 55 protein spots differentially expressed in response to starvation and/or hypoxic stress in one or both strains were identified from 2D gels and classified based on biological function. Antioxidant enzymes, oxidoreducatse enzymes and proteins involved in amino acid metabolism, fatty acid metabolism, ATP and purine biosynthesis, proteolysis, cell wall synthesis, protein synthesis, signal recognition and hypothetical proteins with putative functions including dormancy response regulators and universal stress proteins were identified. These proteins are potential screening targets for future diagnosis, prevention and control of M. a. paratuberculosis infection and their identification will assist understanding the pathogenesis of diseases caused by this organism.     

Periparturient use of parenteral micronised procaine penicillin to reduce the risk of clinical mastitis in heifers after calving

Mastitis in primiparous heifers immediately postpartum can be both a significant welfare concern and a heavy economic loss. Interventions successfully researched include intramammary therapies. This study considered the clinical and practical effects of a parenteral approach to controlling clinical mastitis in heifers immediately postpartum. The objective of this field trial was to determine whether preventative treatment of heifers with a single parenteral treatment of 15 million iu micronised procaine penicillin within 12h after calving would reduce the incidence of clinical mastitis in early lactation as detected by farmers. All heifers (n=609) calving on three commercial dairy farms in New Zealand during the spring of 2006 were randomly allocated to either treatment or no treatment. Treatment (15 million iu micronised procaine penicillin) was given at the first milking following calving. All clinical mastitis was recorded. Treatment reduced the odds of having clinical mastitis within the first 7 days in milk by over half (Mantel-Haenszel adjusted OR=0.456; p=0.044); and reduced the odds of having mastitis within the first 100 days in milk by just under half (Mantel-Haenszel adjusted OR=0.518; p=0.027). Treatment had a significant effect on increasing the median days to clinical mastitis (p=0.019; beta=1.961, LCI 1.117, UCI 3.445). Preventative treatment of heifers immediately following calving with 15 million iu micronised procaine penicillin parenterally could be of benefit as part of a control programme aimed at reducing the incidence of clinical mastitis in heifers in their first lactation.     

The effect of a low molecular weight heparin on coagulation parameters in healthy cats

The low molecular weight heparin (LMWH), dalteparin sodium, was administered subcutaneously (100 IU/kg) to 8 healthy cats twice daily for 13 doses. Anti-activated factor X (anti-Xa) activity was measured prior to administration (time 0), and 4, 6, 8, and 12 h after the 1st dose, 4 h after administration of the 3rd dose, and at 4, 6, 8, and 12 h after the last dose. Four cats developed measurable anti-Xa activity 4 h following a single dose, returning to baseline by 6 h. Anti-Xa activity was not detected at any time point in 4 cats. Prothrombin time (PT), activated partial thromboplastin time (APTT), and antithrombin (AT) concentrations were unaffected by LMWH administration. Dalteparin, at 100 IU/kg SC, did not achieve anti-Xa activity in 4 out of 8 cats and failed to maintain anti-Xa activity beyond 4 h in the other 4 healthy cats.     

野生大豆碱胁迫反应的研究

从吉林省白城市盐碱地采集了野生大豆Glycine soja 345份,用不同盐碱化程度的盐碱土从播种开始胁迫,随着盐碱胁迫程度增加,发芽率和株高逐渐降低,pH值为9.02可抑制50%野生大豆的萌发和生长。用浓度为0、50、75、150、300、500 mmol/L的NaHCO3胁迫3周龄幼苗,浓度为0、50 mmol/L时幼苗可以正常存活,浓度为75、150、300、500 mmol/L时幼苗分别于19、6.5、3、0.5 h左右开始萎蔫。筛选能够在pH值9.0的盐碱土中发芽、生长、开花、结实的野生大豆材料,选择其中发芽率和结实率均较高的9份材料,测定了叶绿素含量、相对电导率和丙二醛含量,编号为G07048、G07092和G07256的3份材料在胁迫前后3个指标差异不显著,具有较强的耐盐碱能力。