四引物扩增受阻突变体系PCR技术在中国明对虾SNP基因分型中的研究

采用四引物扩增受阻突变体系PCR(Tetra-primer ARMS-PCR)技术,对中国明对虾(Fenneropenaeus chinensis)的80个单核苷酸多态性位点(Single Nucleotide Polymorphisms,SNPs)进行验证.结果表明,通过优化PCR反应条件、调整内外引物浓度和采取To...     

Genetic characterization of Streptococcus phocae strains isolated from Atlantic salmon, Salmo salar L., in Chile

Streptococcus phocae is a beta-haemolytic bacterium frequently involved in disease outbreaks in seals causing pneumonia or respiratory infection. Since 1999, this pathogen has been isolated from diseased Atlantic salmon, Salmo salar , causing serious economic losses in the salmon industry in Chile. In this study, we used different molecular typing methods, such as pulsed-field gel electrophoresis (PFGE), randomly amplified polymorphic DNA (RAPD), enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR), repetitive extragenic palindromic PCR (REP-PCR) and restriction of 16S–23S rDNA intergenic spacer regions to evaluate the genetic diversity in S. phocae . Thirty-four strains isolated in different years were analysed. The S. phocae type strain ATCC 51973^T was included for comparative purposes. The results demonstrated genetic homogeneity within the S. phocae strains isolated in Chile over several years, suggesting the existence of clonal relationships among S. phocae isolated from Atlantic salmon. The type strain ATCC 51973^T presented a different genetic pattern with the PFGE, RAPD, ERIC-PCR and REP-PCR methods. However, the fingerprint patterns of two seal isolates were distinct from those of the type strain.     

我国新城疫分子流行病学研究进展

新城疫（Newcastle Disease,ND）是严重损害禽类健康的疾病之一，在世界范围内广泛流行，临床以高热、呼吸困难、下痢、神经紊乱、黏膜出血等症状为特征，严重危害禽类的生长繁殖及禽肉生产。新城疫由新城疫病毒（Newcastle Disease Virus,NDV）引起。NDV已有近100年的流行历史，能够感染鸡、鸭、鹅和鸽子等200多种禽类，其基因型众多，易变的基因型给新城疫防控带来巨大困难。鸟类迁徙在病毒跨境传播中起到重要作用，导致我国各地区新城疫疫情时有发生，给养禽业带来巨大的经济损失，严重制约了养禽业的健康发展。NDV分布范围广、宿主流动性强,是危害养禽业的重要病毒。为了解我国NDV的流行情况，通过对其分子流行病学及各基因型的时空分布进行分析，发现我国新城疫主要分布于广西、广东等华南地区，江苏、安徽等华东地区及陕西、甘肃等西北地区。这些地区分离出的高致病性Ⅱ类毒株包括多种基因型，其中基因Ⅱ型和基因Ⅶ型毒株为主要流行株。通过对NDV流行相关数据的整理与分析可为疫情防控和疫苗研究提供参考。