Pregnant women colonized by Streptococcus agalactiae, or group B streptococcus (GBS), are at an increased risk of premature delivery and stillbirth, and their neonates can be endangered by the development of an invasive GBS disease. In this study, the results of the GBS screening among pregnant women performed between 2012 and 2018 (n = 19267) are presented. For the GBS positive samples, the antibiotic susceptibility of the isolated strains was also tested (n = 3554). During the examined period, the colonization rate varied between 17.4% and 19.8%. The overall rate of erythromycin and clindamycin resistance in the GBS positive samples was 34.9% and 34.6%, respectively. The frequency of the erythromycin and clindamycin resistant strains showed an increasing tendency. An analysis of the MALDI-TOF MS spectra of 260 GBS isolates revealed that 46.5% of them belonged to either the ST-1 or the ST-17 sequence types, indicating a high prevalence of these potentially invasive GBS strains in our region. More than half of the strains identified as ST-1 (52.1%) proved to be resistant to erythromycin and clindamycin.

菌核病是菊花生产中的一种重要病害。为明确菊花菌核病病原菌的种类、品种抗性差异和有效的防治药剂,本研究采用组织分离法对病原菌进行分离培养,结合形态学特征、生物学特征和分子生物学研究进行鉴定,并筛选了33个切花菊品种以及7种杀菌剂。结果表明,从感病植株上分离得到的病原菌能够重新感染菊花,并且再次分离得到的菌株与原菌株相同。通过病原菌的形态、感染特征和分子序列分析,确定了该病原菌为核盘菌(Sclerotinia sclerotiorum)。病原菌在酵母浸出粉胨葡萄糖培养基(YEPD)上的生长速度最快,在20~30℃时生长最好,在pH值5~7时生长较快,对碳源的种类要求不严格,以蛋白胨为氮源时生长较好。共筛选了33份菊花材料,未发现免疫及抗病品种,有6份中抗品种,13份中感品种,14份感病品种,且离体与活体接种差异性不大。氟酰胺和肟菌酯对核盘菌具有显著抑制效果,半数效应浓度(EC₅₀)分别为0.09 mg·L^-1和0.65 mg·L^-1;此外,通过接种后喷施杀菌剂发现,氟酰胺和肟菌酯的防治效果分别达到了98.26%和90.93%,显著优于其他杀菌剂。本研究建立了菊花菌核病的鉴定、筛选与防治的基本方法,为后续菊花抗性育种与品种改良奠定了基础。