ACCT 205 Lecture Notes - Lecture 16: Parvovirus B19, Fifth Disease, Hematopoietic Stem Cell
Document Summary
Because of the limited coding capacity of their genome, viral replication is dependent on functions supplied by replicating host cells or by co-infecting helper viruses. Parvovirus b19 is pathogenic for humans and has a tropism for erythroid progenitor cells. It is the cause of erythema infectiosum ( fifth disease. The human bocaviruses have been detected in respiratory specimens from children with acute respiratory disease and in stool samples, but a role in disease is unproven. The icosahedral, nonenveloped particles are 18 26 nm in diameter (figure 1). The particles have a molecular weight of 5. 5 6. 2 106 and a heavy buoyant density of 1. 39 1. 42 g/cm3. They are stable between a ph of 3 and. 9 and withstand heating at 56 c for 60 minutes, but they can be inactivated by formalin, - propiolactone, and oxidizing agents. Virions contain two coat proteins that are encoded by an overlapping, in-frame dna sequence. The genome is about 5 kb, linear, single-stranded dna.
