Ebola virus (EBOV) and Marburg virus (MARV) belong to the family Filoviridae. Filoviruses cause severe filovirus hemorrhagic fever (FHF) in humans, with high case fatality rates, and represent potential agents for bioterrorism and biological weapons. It is necessary to keep surveillance of filoviruses, even though there is no report of their isolation and patients in China so far. To characterize MARV morphology, the Lake Victoria marburgvirus--Leiden was stained negatively and observed under a transmission electron microscope which is one of important detection methods for filoviruses in emergencies and bioterrorism. MARV showed pleomorphism, with filamentous, rod-shaped, cobra-like, spherical, and branch-shaped particles of uniform diameter but different lengths. Pleomorphism of negatively stained MARV is summarized in this article, so as to provide useful information for possible electron microscopic identification of filoviruses in China.
Animals ; Humans ; Marburg Virus Disease ; virology ; Marburgvirus ; growth & development ; ultrastructure ; Microscopy, Electron, Transmission ; Virion ; growth & development ; ultrastructure

This study was designed to discover filovirus entry inhibitors in a drug library of commercial medicines. One thousand and six hundred drugs were screened using the ZEBOV-GP/HIV model, a pseudovirus formed by an HIV-core packed with the Zaire Ebola virus glycoprotein. We identified 12 gonadal hormone drugs with inhibitory activities in ZEBOV-GP/HIV entry at final concentration of 10 μmol x L(-1). Among them, three drugs exhibited strong activities with IC50 < 1 μmol x L(-1), such as toremifene citrate (IC50: 0.19 ± 0.02 μmol x L(-1)), tamoxifen citrate (IC50: 0.32 ± 0.01 μmol x L(-1)) and clomiphene citrate (IC50: 0.53 ± 0.02 μmol x L(-1)); seven drugs had moderate activities with IC50 between 1 and 10 μmol x L(-1), such as estradiol benzoate (IC50: 1.83 ± 5.69 μmol x L(-1)), raloxifene hydrochloride (IC50: 3.48 ± 0.07 μmol x L(-1)), equilin (IC50: 4.00 ± 9.94 μmol x L(-1)), estradiol (IC50: 5.26 ± 9.92 μmol x L(-1)), quinestrol (IC50: 6.36?5.37 gmol-L1), estrone (IC50: 6.87 ± 0.03 μmol-L1) and finasteride (IC50: 9.94 ± 0.45 μmol x L(-1)); two drugs, hexestrol (IC50: 14.20 ± 0.55 μmol x L(-1)) and chlormadinone acetate (IC50: 24.60 ± 0.36 μmol x L(-1)), had weak activities against ZEBOV. Further, toremifene citrate, tamoxifen citrate, clomiphene citrate, raloxifene hydrochloride and quinestrol could block both pseudovirus type Sudan ebola virus (SEBOV-GP/HIV) and Marburg virus (MARV-GP/HIV) entries.
Antiviral Agents ; pharmacology ; Drug Evaluation, Preclinical ; Ebolavirus ; drug effects ; physiology ; Hemorrhagic Fever, Ebola ; Humans ; Marburgvirus ; drug effects ; physiology ; Selective Estrogen Receptor Modulators ; pharmacology ; Virus Internalization ; drug effects