Outbreak of anaplasmosis associated with novel genetic variants of Anaplasma marginale in a dairy cattle

During early lactation, dairy cows may present a transient immunosuppressive state and develop anaplasmosis caused by Anaplasma marginale. In this study, clinical anaplasmosis in dairy cattle in the Thrace region of Turkey was investigated with respect to within-herd prevalence, vertical transmission, and genetic diversity. In March and September 2015, thirty lactating cows showed primary clinical signs of anaplasmosis, including fever, anaemia, decreased milk yield, anorexia, and laboured breathing. Symptoms disappeared in most cows after administration of long-acting oxytetracycline, but nine of them (30%) died. Following diagnosis based on clinical signs, microscopy and molecular findings, blood samples were collected from apparently healthy lactating cows (n = 184), pregnant heifers (n = 39) and newborn calves (n = 24). DNA was extracted from each sample and analyzed for the presence of major surface proteins (MSPs) of A. marginale, followed by sequencing to assess diversity of isolates. Microscopic examination of erythrocytes revealed A. marginale inclusion bodies in symptomatic cows. Examination of thin blood smears showed 3.8% of the lactating, clinically asymptomatic, cows to be infected with A. marginale, while nPCR detected 31.0% positive. A. marginale infection was not detected in pregnant heifers by either method. Congenital infection was found in one calf by nPCR. This is the first report of transplacental transmission of A. marginale in Turkey. The MSP4 sequence analyses showed high genetic diversity among the isolates, presenting 97.6-99.6% homology at the amino acid level. The sequences of MSP1a amplicons revealed genetic diversity providing three new tandem repeats.     

枯草芽孢杆菌在番茄病害防治上的应用与研究进展

综述了枯草芽孢杆菌在防治植物病害中的生防机制,包括竞争作用、拮抗作用、溶菌作用、诱导植物产生抗性和促进植物生长5个方面,介绍了枯草芽孢杆菌在6种番茄病害即灰霉病、青枯病、早疫病、立枯病、枯萎病、根腐病防治中的应用,并对其应用中存在的主要问题进行了总结、前景进行了展望。     

浅谈阜新蒙古族自治县玉米膜下滴灌农艺措施

以玉米膜下滴灌栽培技术研究成果为依据，总结了辽宁省阜新蒙古族自治县东部地区推广应用该成果的具体措施，并提出相应对策。     

Epidemiology of cashew anthracnose (Colletotrichum gloeosporioides Penz.) in Mozambique

Anthracnose of cashew (Anacardium occidentale) was studies on various genotypes and locations in Mozambique. Colletotrichum gloeosporioides was identified as the anthracnose causal agent using polymerase chain reaction. The relationships between incidence and severity of anthracnose on cashew genotypes were statistically analyzed by regression. Anthracnose leaf incidence, which is practically easy to evaluate, was consistently associated with leaf severity, and their relationships can be estimated using the restricted exponential function across locations, crop seasons, genotype and fungicide trials. Pooled data enabled estimation of initial incidence of 1.43% with percentage variance accounting for 83.2 and standard error of 8.3. By computing incidence data into the summary equation, 24 changes of 0, 1, 5, 10 and 40%, resulted in changes of severity estimates of 0.01, 0.05, 0.10, 0.50 and 1.00%, respectively. The maximum disease incidence was estimated as 80% when the severity reached only 5%. Increase in severity was observed afterward, approached a maximum of 25% when leaf detachment is observed. The use of incidence data for epidemic comparisons, genotype and fungicide evaluation in cashew orchards is recommended. Anthracnose incidence on leaves however, could not predict incidence on nuts.     

牛病毒性腹泻病毒检测方法研究进展

引起牛病毒性腹泻/黏膜病(bovine viral diarrhea—mucosal disease,BVD—MD)的病原为牛病毒性腹泻病毒(Bovine viral diarrhea virus,BVDV),牛感染后会出现与其他腹泻病相似的症状,仅通过临床表现和病理观察很难做出准确鉴别;其次持续感染(PI)牛是该病主要传染源,如何鉴别、净化牛场中PI牛十分重要。为了检测BVDV病原和净化PI牛,选择一种最佳的检测方法非常重要。文章对目前常用的不同BVDV检测方法进行了比较分析。不同检测方法在敏感性、特异性等方面均存在差异。实际应用时应根据检测目的综合考虑,选择适宜的检测方法。