从白喉棒状杆菌PW8株中筛选高产毒株

Corynebacterium diphtheria PW8-weissensee was grown on different mediafor screening high toxin produce. Through six times of screening (selecting butyrousbrilliant smooth small colonies and teshng their toxin production capacity) fromoriginal strain producing toxin l60Lf/ ml, a high toxin- producing descendandculture was obtained, which produced 79% more toxin than the original strain did.

流行性感冒病毒鸡胚高产株的遗传特性分析

Influenza virus strain A/PR/8/34(H1N1)acquired a high-yielding property after serial passages in fertilized eggsSix internal RNA segments of the high-yielding strain were sequenced from their cloned cDNAs and compared with the corresponding original sequences in the prime A/PR/8/34(H1N1)strainNinety-three point mutations were found accumulated in six genes(PB2,PB1,PA,NP,M,and NS),which lead to 27 amino acid changesA significant low mutation frequency without amino acid change was observed in PA geneThe mutation frequency at the amino acid level was the highest(about 3%)in M2 proteinOur data suggest that the unequal distribution of mutations among different viral proteins may correlate with individual role of each protein in viral

提高病毒疫苗抗原产量的策略

疫苗接种是预防传染病的一种重要策略。然而,目前许多疫苗在生产过程中存在抗原产量偏低的问题,由此导致疫苗的生产成本较高、有效抗原含量低和免疫效果差等问题。为此,研究人员尝试了不同策略来提高病毒疫苗抗原的产量,以改进疫苗的质量并降低生产成本。文中总结了近年来提高疫苗中病毒抗原产量的主要方法,包括改造病毒基因、改善病毒对细胞的适应性、优化抗原表达体系、改进疫苗生产工艺等方面。并分析了不同策略的优点和存在的问题,提出了提高疫苗抗原产量的一些设想。